1.2.1

Goel K, Lennon RJ, Tilbury RT, Squires RW, Thomas RJ. Impact of cardiac rehabilitation on mortality and cardiovascular events after percutaneous coronary intervention in the community. Circulation 2011;123(21):2344–52

This retrospective observational study carried out in Olmstead County (Minnesota) deals with the effects of the enrollment – or not – in a cardiac rehabilitation (CR) program following percutaneous revascularization (dilatation or stent). The data pertaining to 2395 consecutive patients having undergone revascularization between 1994 and 2008 were analyzed by means of three robust statistical methods. During the follow-up period (6.3 years on the average), the authors recorded 503 deaths including 199 for cardiac reasons, 394 cases of acute coronary syndrome (ACS) and 755 revascularization procedures. The rate of participation in the CR program was 40%, with an average of 13 sessions taking place over the 3 months subsequent to the procedure. The results with regard to the primary criteria show significantly less all-cause mortality (RR: −45% to −47%) in CR program participants, with a pronounced tendency towards diminished cardiovascular mortality, regardless of sex, age and degree of urgency of the indication for revascularization. No effect was noted as concerns event recurrence or the new procedures. In order to explain this outcome, the authors put forward two hypotheses: (1) enhanced follow-up of the rehabilitating patients led to earlier detection and treatment of relapses; (2) the results were due to a diminution of the fatal events that led to an increase in non-fatal events, as is attested in this work by a lower composite rate of events (all-cause mortality + non-fatal heart attacks) in the rehabilitating group.

This work nonetheless shows a number of limitations, particularly as regards the lack of description of the rehabilitation programs carried out and a somewhat “elastic” definition of participation in the latter (participation in at least one session over the 3 months subsequent to the procedure) that may explain an inclusion rate higher than most of those generally reported in France and other European countries. Moreover, the indications for revascularization are not always clearly described. The study nonetheless has the interest of reflecting results encountered in “real life” and thereby differs from the clinical studies often opposing different types of management to each other. Such efforts have indeed underscored the interest of non-drug treatments, particularly for unstable angina , but they only partially reflect the usual experience of patients ideally benefiting from the two complementary types of management. Lastly, this work provides additional arguments of possible interest to the competent authorities in favor of the national and international recommendations on CR subsequent to revascularization for ACS (Class 1, Grade A), for stable angina and following planned angioplasty (Class 1, Grade B) . On the other hand, at the end of 2011 a negative trial on the effects of CR was published, but various peculiarities and/or limitations mean that the results should be interpreted cautiously . In this multicenter study conducted in Great Britain, the authors analyzed the clinical course of 1813 patient randomly divided into either a group undergoing CR (one or two outside sessions a week, for 6 to 8 weeks) or with control group receiving the usual care. The results were negative as regards the primary criteria, that is to say all-cause mortality at 2 years (RR = 0.98, 95% CI: 0.74–1.30) and also at 7–9 years (RR = 0.99, 95% CI: 0.85–1.15). Moreover, there was no difference as regards cardiac events, quality of life (excepting the SF-36 “physical function” sub-scale score) and physical activity. If these results should, so we repeat, be interpreted cautiously, there are several reasons. Firstly, the trial was prematurely interrupted on account of the funder’s withdrawal from a project in which calculation of the initial sample was predicated on inclusion of 3000 patients by category. Secondly, the study deals with patients included between 1997 and 2000; it is quite possible that since those dates, the CR programs have significantly changed. Lastly, these results are unlikely to be generalizable to other countries with different programs. Moreover and on the contrary, a meta-analysis recently conducted by Lawler et al. confirmed once again a reduction of mortality and event recurrence following a heart attack in patients having benefited from CR based on functional restoration programs (FRP). The main new element in this meta-analysis consists in its highlighting the probable efficacy of short programs, but this finding remains to be confirmed by larger, randomized trials. To conclude, the effectiveness of short and intense programs with regard to quality of life, anxiety-depression and quality of sleep has also been reported on an open French study involving 101 patients .

1.2.2

Temfemo A, Chlif M, Mandengue SH, Lelard T, Choquet D, Ahmaidi S. Is there a beneficial effect difference between age, gender, and different cardiac pathology groups of exercise training at ventilatory threshold in cardiac patients? Cardiol J 2011;18(6):632–8

The objective of this work was to compare the benefits of an individualized exercise program carried out at the heart rate observed at ventilatory threshold (8 weeks, three sessions of 45 minutes per week) for patients included in a CR program in accordance with age, sex and type of pathology. The study included 188 patients (62 post-bypass, 62 post-angioplasty along with 54 post-infarction and 50 valve replacement patients). Maximum performance, peak VO ₂ , VO ₂ at ventilatory threshold and heart rate at rest were all enhanced in every patient, regardless of age, sex and type of cardiac pathology. This study confirms both the interest of proposing these programs to different types of patients and the premise that age should not represent a contraindication. On the whole, these results have been corroborated by the meta-analysis of Sandercock et al. published at the end of 2011. The authors detail in revascularized post-infarction and angina patients the effects of the CR programs on exercise capacity and analyze the factors explaining the improvements (previous meta-analyses had rather dealt with their effects on morbi-mortality). The combined results of 31 studies (3827 patients) show mean improvement of 1.55 METs (95% CI: 1.21–1.89; P < 0.001), which is a clinically relevant finding since it has been reported that an improvement of one MET gives rise to a 12% decrease in relative risk of mortality . And in this analysis, even though patient characteristics substantially differ from those observed in the study by Temfemo et al. , it would appear that the gains are greater in patients having undergone at least 36 sessions, in young people and in men. Conversely, the improvements were independent of type of program (multidisciplinary or based on exercise alone) and initial exercise capacity, which means that the programs may constructively be proposed to even the most deconditioned patients. Finally, aside from physical characteristics and types of cardiac pathologies, comorbidities can obviously impede CR programs. Nevertheless, in another study, Listerman et al. tend to show that even if associated pathologies can indeed affect outcomes, all of the patients derive benefit from the programs. In their sample of 794 coronary patients (61.6 ± 10.6 years, 29% women) having taken part in a CR program between 1996 and 2008, the authors have analyzed the outcomes of three sub-groups: (1) no associated comorbidity ( n = 305), (2) moderate comorbidity index (1 to 2, n = 305) and (3) index greater than 2 ( n = 184). At the end of the program, improvement was noted with regard to the distance covered in the 6-minute walk test, BMI and quality of life in all three sub-groups. Among the youngest (< 56 years), the patients without associated comorbidity showed improvement significantly more pronounced than the patients under 56 years of age in the other two sub-groups. Conversely, among older patients, improvement was independent of the associated comorbidities.

1.2.3

Giallauria F, Acampa W, Ricci F, Vitelli A, Maresca L, Mancini M, Grieco A, Gallicchio R, Xhoxhi E, Spinelli L, Cuocolo A, Vigorito C. Effects of exercise training started within 2 weeks after acute myocardial infarction on myocardial perfusion and left ventricular function: a gated SPECT imaging study. Eur J Cardiovasc Prev Rehabil 2011 Sep 30

The goal of this work was to compare the evolution of exercise capacity and ventricular remodeling (evaluated with a technique more recent than thallium perfusion) in 50 patients having presented with ACS and ST-segment elevation (ACS-ST+); they were randomly divided into a “usual care” group ( n = 26, dietetic and lifestyle counseling along with regular physical exercise) and an intervention group ( n = 24, 6-month CR program starting 9 ± 3 days following the event). As expected, at 6 months only the intervention group showed a significant increase with regard to peak VO ₂ , VE/VCO ₂ slope and O ₂ pulse along with improvement in residual stress ischemia evaluated by ECG-synchronized spectrometry, improvement in parietal kinetics at rest and post-stress and in parietal thickness, but not in the ejection fraction. The authors explain this last result by the possible need for a longer period enabling observation of a transfer to this parameter of the improvements induced by training in parietal kinetics. No modification of the myocardial perfusion or ventricular remodeling parameters was observed in the control group. The study presents some limitations: the amount of physical activity undertaken by the control group was not reported, and the essentially multidisciplinary nature of the rehabilitation program does not justify attribution of the observed effects to exercise alone. It nonetheless confirms the possibility of quite rapidly proposing these programs to patients having presented with ACS-ST+, in which case the inclusion rate of patients in rehabilitation could be increased, with the close proximity of the cardiac event perhaps rendering them more inclined to agree to admission to the cardiac rehabilitation wards. In any event, these results are in agreement with the meta-analysis put forward by Haykowsky et al. , who confirmed the positive effects of exercise on ventricular remodeling in stable post-infarction patients, with an effect on the ejection fraction that was less and less pronounced the longer the time lapse between the acute event and the onset of rehabilitation. In fact, the most pronounced benefits occurred in the programs commencing the earliest and lasting at least 3 months. This trend has also been noted in management of heart failure patients, as is attested in the pilot study by Houchen et al. , who showed in 17 patients (including 13 men; mean age 67.3 ± 10.4; NYHA II–IV) hospitalized for acute left-sided cardiac decompensation the feasibility, innocuousness and effectiveness of a 6-month CR program starting within 4 weeks after discharge from intense care, and showing significant improvement within 1 year in exercise capacity (measured by shuttle-walking tests; one with respect to stamina, the other one incremental) and depression score as measured on the HAD scale (but not the anxiety score). Moreover, there were significantly fewer cases of hospital readmission within a year in comparison with the year preceding the acute episode triggering the CR.

1.2.4

Montiel-Trujillo A, Isasti-Aizpurua G, Carrasco-Chinchilla F, Jimenez-Navarro MF, Gomez-Gonzalez A, Bravo Navas JC, et al. Influence of cardiac rehabilitation on natriuretic peptides. Acta Cardiol 2011;66(5):641–3

This work deals with the question of the impact of exercise on the NT-proBNP ratio. The authors analyzed the evolution of this biological marker of left ventricular dysfunction before and after rehabilitation, and also before and after an exercise session, in 83 intermediate-to-high-risk patients. The exercise sessions brought about an increase of the NT-proBNP level that was less pronounced subsequent to the training. The patients presenting with ventricular dysfunction obviously likewise presented with higher NT-proBNP ratios and following the program, they showed mean exercise capacity improvement of 1.5 METs, whereas exercise capacity was not significantly enhanced in the sub-group with the lowest NT-proBNP ratios. The patients presenting with the highest initial levels achieved the most satisfactory functional recovery. The authors draw the conclusion that the NT-proBNP level might be useful in the selection of patients to be included in CR programs. These results are in congruence with those reported by Giallauria et al. , who claim that the degree of diminution of the NT-proBNP ratio could serve as a predictor of ventricular remodeling . Nevertheless, a still more recent HF-Action study showed that though NT-proBNP ratio was the best predictor of VO ₂ in the cohort of heart failure patients studied, the correlation remained relatively weak and that for the most part, exercise capacity variability was not adequately explained by clinical and biological factors .

1.2.5

Jolly MA, Brennan DM, Cho L. Impact of exercise on heart rate recovery. Circulation 2011;124(14):1520–6

Enhanced functioning of the autonomic nervous system (ANS) is a classic effect already objectified in several previous works on coronary and heart failure patients. The aim of this study was to determine whether or not improved heart rate recovery (HRR) is a major prognostic criterion with regard to coronary patients. With this in mind, 1070 patients included in a CR program underwent a HRR analysis before and immediately following an endurance program. The results showed that lack of HRR improvement as measured 1 minute after the exercise testing (exercise stress test) was an accurate predictor of mortality (RR at 2.15; 95% CI: 1.43–3.25, P < 0.05) (mean patient follow-up: 8.1 years). This study represents a breakthrough in the evaluation of patients having undergone CR programs; the chosen criterion is simple, inexpensive and potentially applicable to all patients involved. It should nonetheless be mentioned that its evaluative use entails strict respect of an invariably similar protocol for measurement of the heart rate immediately following the exercise testing. For example, in this study the exercise stress test was carried out on a treadmill with active recovery at 2.4 km/h with a 2.5% slope. On the basis of previous work, the threshold selected in consideration of a normal recovery was a heart rate decrease strictly greater than 12 beats a minute.

The study nonetheless presents some limitations, the main one being that it constitutes a retrospective trial requiring confirmation through new work. The outcome reported nevertheless underlines the interest of CR in detection of patients at particularly high risk of mortality, as was already shown in another study of a heart failure population, with lack of VO ₂ peak improvement constituting a predictor of higher morbi-mortality. These findings suggest a need to modify the latter-stage therapeutic approach towards patients remaining at high cardiovascular risk notwithstanding the CR program.

In addition, this study offers no window on the evolution of the parameters reflecting ANS activity subsequent to the CR period. Fortunately, however, another essay published in 2011 allows for an answer to the preceding question . The attendant study included 28 patients in the wake of ACS (STEMI and non-STEMI heart attacks) randomly divided into two groups (exercise vs. non-exercise/control). They were evaluated at 2 to 5 days, 1 month, 3 months and 7 months after ACS in terms of not only functional parameters (VO ₂ peak), but also spontaneous barofeflex sensitivity (SBR) and muscle sympathetic nerve activity (MSNA). At 3 months and 7 months, the results showed SBR, MSNA and VO ₂ peak improvement in comparison with the control group. While these results confirm those of other studies , in this instance they involve a larger population. The ANS analysis, in particular, might serve as an efficiency marker with regard to CR programs and could facilitate future decisions as to (re)providing medical care in accordance with whether or not the ANS parameter has been altered following ACS. It would appear that the effects of exercise retraining on the ANS are quite pronounced; in this study, the parameters of evaluation, particularly MSNA, have at 3 months improved in the exercise group and become comparable to those of matched healthy subjects after 7 months of exercise. It would consequently make sense that CR programs, which in France are generally of short duration (3 to 6 weeks) be relayed by phase III programs facilitating maintenance of regular physical activity.

1.3.1

Berent R, von Duvillard SP, Crouse SF, Sinzinger H, Green JS, Schmid P. Resistance training dose response in combined endurance-resistance training in patients with cardiovascular disease: a randomized trial. Arch Phys Med Rehabil 2011;92(10):1527–33

This work was aimed at measuring the effect of resistance training workload complementary to aerobic exercise in patients undergoing a phase 2 or phase 3 CR program. Two hundred and ninety-five (295) patients (62.7 ± 11.7 years) were randomly divided into groups carrying out at each training session either 2 × 12 repetitions (REPS) or 3 × 15 REPS of exercises involving the large muscle groups solicited in daily life activities (two sessions a week for 5 or 6 weeks). The workload was determined by a preliminary test in which the patient was asked to perform 13 to 15 repetitions at levels 4 to 6 on a modified 7-level Borg scale (MBS), with the workload meant to represent approximately 50% of maximal capacity (I-RM). The results show no difference between the two groups as concerns improved muscle strength, exercise capacity, and the hemodynamic and biological parameters under consideration, and no adverse side effects were to be noted. The authors conclude that the fact of practically doubling the number of muscle exercises (45 repetitions in three series vs. 24 repetitions in two series for each muscle group) yields no supplementary benefit. The study presents some limitations insofar as the population studied was highly heterogeneous with regard to both the pathology (post-ACS, post-bypass or valve surgery, heart failure) and to the time lapse with respect to the diagnosis or the acute event. The resistance training workload used in the study was comparable to the recommendations of the German Federation for Cardiovascular Prevention and Rehabilitation , but this study was one of the first major trials to attempt comparison of the effects of different training volumes on muscle strengthening. On this subject, the effects of programs combining muscle reinforcement with aerobic exercise were confirmed in 2011 in a meta-analysis including 12 different studies, and it would consequently appear important to pursue work facilitating personalized muscle strengthening prescriptions with optimal cost–benefit ratio while taking into account comorbidities, particularly in the bones and joints, for which a 50% prevalence has been reported by Marzolini et al. . Even in these types of patients, the authors report improvement, provided that the prescription is sufficiently customized, and its adaptation to their needs necessitates the array of multidisciplinary skills proper to CR units.

1.3.2

Carvalho VO, Roque JM, Bocchi EA, Ciolac EG, Guimaraes GV. Hemodynamic response in one session of strength exercise with and without electrostimulation in heart failure patients: A randomized controlled trial. Cardiol J 2011;18(1):39–46

This work was aimed at evaluating acute hemodynamic responses (heart rate along with systolic and diastolic blood pressure) during a muscle strengthening session involving the quadriceps (three series of eccentric contractions of the quadriceps of the dominant leg in a standing position) and associated or not associated with electrostimulation of the medial and lateral vastus muscles at an intermediate frequency (50 Hz) in 10 heart failure patients (mean left ventricular ejection fraction 31 ± 5%). The authors report no difference between the two conditions in terms of heart rate or blood pressure; moreover, there was no complaint of muscle pain immediately following or 24 hours after the exercise. This work brings together two kinds of strength training of particular interest in deconditioned patients, namely eccentric muscle exercise and neuromuscular electrostimulation (ESM). As regards the latter, the scientific community taken as a whole henceforth recognizes its pertinence in conservation and/or recovery of muscle mass during or after a period of immobilization or non-utilization . The technique has been the subject of several, mainly European studies pertaining to its efficacy in improvement of effort capacity (VO ₂ peak) and functional capacities (6-minute walk test) as well as muscle strength itself . In 2012, these works constituted the subject of a meta-analysis confirming the effectiveness of this technique as concerns the VO ₂ peak in comparison with a control group receiving the usual care without exercise or undergoing sham electrostimulation (mean improvement ± 46.9 m). This analysis also took note of a highly positive effect on quality of life as measured by the Minnesota Living with Heart Failure score. Moreover, total duration of the functional electric stimulation was highly correlated with VO ₂ peak gain. In comparison with aerobic retraining, on the other hand, this meta-analysis did not reveal differences as concerns quality of life, muscle strength or distance covered in the 6-minute walk test, while the VO ₂ peak appeared to have significantly improved with aerobic retraining (+0.32 mL/kg per minute). To conclude, it should be mentioned on the one hand that the just-cited results are based on a small number of studies including relatively few patients, and on the other hand that in association with increasingly convincing demonstrations of the technique’s efficacy, the work by Carvalho et al. serves to underline its interest as an alternative, particularly with regard to highly deconditionned or frail patients and in cases where dynamic retraining is out of the question.

Moreover, eccentric muscle strengthening could also be an interesting alternative for these patients insofar as it facilitates higher gains of muscle strength along with lowered oxygen consumption . Even though it still meets up with some reluctance stemming from fears of the delayed–onset muscle soreness frequently encountered in sports practice, its hemodynamic tolerance and its effectiveness in improving exercise capacity and muscle strength have already been confirmed in coronary patients , and a recent study likewise demonstrated its functional benefits through improved performance in standardized walk tests . Even more recently, tolerance for eccentric muscle strengthening was shown in patients with severe chronic obstructive bronchopneumopathy (COPD) , and its application in heart failure patients may legitimately be envisaged, since the intrinsic alterations affecting the skeletal muscles of these patients appear comparable to those reported in cases of COPD .

1.3.3

Caminiti G, Volterrani M, Marazzi G, Cerrito A, Massaro R, Sposato B, et al. Hydrotherapy added to endurance training versus endurance training alone in elderly patients with chronic heart failure: a randomized pilot study. Int J Cardiol 2011;148(2):199–203

This work was aimed at determining whether or not management combining hydrotherapy (HT) and aerobic endurance training (ET) is superior to ET alone in heart failure patients. Twenty-one male patients (68 ± 7 years, left ventricular ejection fraction 32 ± 9%, NYHA classes II-III) were randomly divided into a combined training group (CT: HT + ET; n = 11) and a group undergoing ET alone ( n = 10). There were three sessions a week for 24 weeks associating warm-ups (walking through water) and segmental exercises involving the upper and lower limbs through 10 repetitions by set of exercises, with the sets steadily increasing in number. The results showed significant improvement in both groups in the distance covered during the 6-minute walk test, but the improvement was significantly more pronounced in the CT group. As for diastolic blood pressure and heart rate, only in the CT group was a significant diminution recorded. In both groups, muscle strength improved, without intergroup difference. The authors conclude that for these types of patients, the combined program improves functional walking capacities as well as the hemodynamic profile. Were these results to be confirmed, hydrotherapy could be envisioned as an interesting addition to classical aerobic exercise insofar as it allows for variations in the kinds of exercises offered. More specifically, it may constitute a worthwhile alternative for obese patients, both enhancing their comfort level and minimizing risk of bone or joint injury.

1.3.4

Bosnak-Guclu M, Arikan H, Savci S, Inal-Ince D, Tulumen E, Aytemir K, et al. Effects of inspiratory muscle training in patients with heart failure. Respir Med 2011;105(11):1671–81

This study was aimed at evaluating the effects of specific training of the inspiratory muscles (IMT) with regard to functional capacity and balance, respiratory and peripheral muscle strength, pulmonary function, dyspnea and fatigue, depression and quality of life in heart failure patients. In this double-blind prospective study, 30 patients (NYHA II-III, LVEF < 40%) were randomly divided into a group benefiting from IMT at 40% of maximal inspiratory pressure ( n = 16) and a group undergoing sham training (15% of maximal inspiratory pressure, n = 14) over 6 weeks. All of the analyzed parameters showed more significant improvement in the 40% group, except for quality of life and fatigue, which showed improvement without intergroup difference. The authors draw the conclusion that this kind of training should be more frequently included in cardiopulmonary rehabilitation programs. Their results provide confirmation of those reported in 2004 by Laoutaris et al. . Cardiac rehabilitation units could derive substantial benefit from investment in special equipment that would not only help the directly concerned patients, but could usefully be extended to all patients at the postoperatory stage, especially those presenting with respiratory complications.

1.4.1

Mourot L, Tordi N, Bouhaddi M, Teffaha D, Monpere C, Regnard J. Heart rate variability to assess ventilatory thresholds: reliable in cardiac disease? Eur J Cardiovasc Prev Rehabil 2011 Sep 13. [Epub ahead of print]

This study applies to heart failure and/or coronary patients an original idea developed in 2006 with regard to healthy subjects practicing sports and involving the determination of ventilatory adaptation thresholds (first and second ventilatory thresholds) from heart rate variability registered by heart-rate monitoring alone, without resorting to pneumotachographic measurement of the respiratory parameters. With their 14 heart failure and 24 coronary patients, the authors compared the determinations of thresholds from the RR intervals that were analyzed in comparison with the determination derived from the exercise test in accordance with the same incremental exercise protocol. As regards existing methods of analysis of the RR interval, three were tested, and the first dealt solely with how the standard deviation of RR intervals (SDNN) evolved over successive one-minute periods, its diminution being interrupted during the exercise. As for the second method, it measured over successive one-minute periods the variability (standard deviation) of the differences between the successive RRs over during each period. Using the curve, the experimenters tried to detect the moment at which the aforementioned variability no longer diminishes during exercise (i.e. diminution less than 1 ms with regard to the preceding period). Finally, the third method takes into account the instantaneous spectral analysis by fast Fourrier transform (FFT) of the RR figures. Using this analytical software, the data curve is divided into successive 3-second periods, which leads to extraction of the peak frequency (fHF) of heart rate variability (HRV) and of high-frequency spectral power, that is to say for frequencies ranging from 0.5 to 1.8 Hz (HF), with the result of these two frequency measurements being monitored during the incremental exercise. In order to calculate the ventilatory thresholds, it is necessary to locate a first breakpoint (first ventilatory threshold) and then a second breakpoint (second ventilatory threshold) during the test. The outcomes of this study show that contrarily to the first two methods proposed, the third method is quite satisfactorily correlated with the classical determination of the ventilatory thresholds through gas-exchange analysis (mean difference in heart rate less than 5%, correlation coefficient of 0.78 (VT1) and 0.95 (VT2), ( P < 0.05). This method for evaluating thresholds is quite promising insofar as it may be carried out in more ecological contexts (field tests) or in cases where respiratory parameters cannot be measured, namely in centers lacking the necessary equipment or not having a specialist with expertise allowing for interpretation of the results drawn from gas-exchange measurement.

1.4.2

Schnohr P, Marott JL, Jensen JS, Jensen GB. Intensity versus duration of cycling, impact on all-cause and coronary heart disease mortality: the Copenhagen City Heart Study. Eur J Cardiovasc Prev Rehabil 2012;19(1):73-80. Epub 2011 Feb 21

This study was aimed at examining the impact of the two exercise parameters, that is to say exercise intensity and duration, on all-cause and on coronary heart disease death. 5106 apparently healthy cyclists, aged from 20 to 90 years, were included and monitored for 18 years. The results showed that relative intensity, and not duration, was closely associated with the figures registered for both all-cause and heart disease death. The study was conducted with a large cohort and the results reinforce the idea that in order to optimally affect health, exercise intensity should be prescribed as precisely as possible, and not be neglected in favor of longer sessions at lesser intensity. The authors consequently recommend that adults in primary prevention pedal vigorously rather than slowly.

1.4.3

Guiraud T, Nigam A, Juneau M, Meyer P, Gayda M, Bosquet L. Acute responses to high-intensity intermittent exercise in CHD patients. Med Sci Sports Exerc 2011;43(2):211–7

This study was aimed at carrying out a comparison, in stable coronary patients, between acute cardiorespiratory responses following a session of high-intensity interval exercise (alternation of 15 s phases at 100% of peak power output [PPO] with 15 s phases of passive recovery) and a continuous isocaloric exercise session carried out at 70% of PPO. No clinical, electrical or biological signs of ischemia (troponin T measurement), significant arrhythmia or abnormal blood pressure response were observed. Notwithstanding a degree of exercise intensity equal to 100% of PPO, all of the patients preferred the interval exercise protocol, with a mean score on the Borg scale of 14 ± 2 for HIIE versus 16 ± 2 for the continuous exercise (MICE) ( P < 0.05). This result may be explained by possible metabolic recuperation during the passive recovery phases (lowered VO ₂ , energy restocking). Nevertheless, even when a patient refrains from pedaling during the 15-second passive recovery intervals, the energy expenditure remains high, and an excellent effectiveness-comfort ratio is thereby attained.

Patients’ preference for HIIE may also be due to a sensation of lessened dyspnea, since mean ventilation was pronouncedly lower (58.9 ± 14.2 and 49.8 ± 8.2 L/min for moderate-intensity and high-intensity exercise respectively P < 0.001). As dyspnea is a factor that limits exercise, HIIE could help to improve long-term commitment to the CR program. Moreover, the change in rhythm imposed by the exercise is perceived by the patient as playful, which means that at times he forgets about the amount of effort to be exerted, and is that much more inclined to observe the rules . Finally, HIIE appears particularly interesting because in addition to its more pronounced effect on improvement of the VO ₂ peak, this type of intense exercise (85–100%) of the VO ₂ peak is also more effective than MICE in reduction of cardiovascular risk factors and insulin resistance .

1.4.4

Meyer P, Normandin E, Gayda M, Billon G, Guiraud T, Bosquet L, et al. High-intensity interval exercise in chronic heart failure: protocol optimization. J Card Fail 2012;18(2):126–33. Epub 2011 Nov 25

This study was aimed at comparing acute cardiopulmonary responses reported during the different HIIE protocols, and its goal consisted in characterizing the optimal protocol for heart failure patients. The principle was to assess duration of exercise tolerance time on an ergocycle in accordance with four distinct combinations that varied recovery intensity (0 to 50% of PPO) and exercise phase duration (30 s or 90 s) while the exercise/recovery ratio (1:1) remained the same, as did exercise phase intensity (100% of PPO). No heart rhythm disorder was observed, nor was there any biological ischemia stigmata (troponin T), ventricular overload or aggravated inflammatory syndrome. Taking into consideration total exercise time, preferred means of exercise, perception of effort, patient comfort and time spent at a high-percentage VO ₂ peak, short-interval (30 s) exercise and passive recovery appeared to constitute the optimal HIIE protocol for these types of patients .

Most studies on training have involved long exercise intervals (3–4 min) and long recovery periods (close to 50% of maximal VO ₂ ) . These works are the present-day references, but unfortunately, up until now they have not dealt, in principle, with acute responses. Even given the highly encouraging results with regard to acute exercise in terms of cardiovascular responses and innocuousness, the feasibility of the protocol devised by Meyer et al. still needs to be validated throughout a training program. It should nonetheless be mentioned that it appears to be well-tolerated by patients with limited physical capacities.

1.4.5

Moholdt T, Aamot IL, Granoien I, Gjerde L, Myklebust G, Walderhaug L, et al. Long-term follow-up after cardiac rehabilitation. A randomized study of usual care exercise training versus aerobic interval training after myocardial infarction. Int J Cardiol 2011;152(3):388–90

In this randomized study, Moholdt et al. compared the effects of a supervised 12-week program at a center employing either continuous or high-intensity interval exercise on functional capacity and on the different biological markers of post-infarct patients. The results indicate that both types of exercise improve endothelial function, the level of adiponectin circulating in serum, and quality of life. They also help to reduce the circulating level of serum ferritin and the heart rate of a patient at rest. As for HDL cholesterol, only following the intermittent exercise program did its level increase. The VO ₂ peak was significantly higher after HIIE than after traditional, continuous training ( P < 0.005). Moreover, the difference between the groups in terms of VO ₂ peak persisted after 30 months of home follow-up ( P < 0.005). These findings may be explained by a more pronounced improvement during the initial phase at the center along with a lessened decline during home follow-up, which would appear to once again show that given its playful aspect, HIIE has taken on a major role in attempts to ensure that patients observe the rules of the game.

To sum up, HIIE appears to be highly suitable for the coronary patient and its superiority to continuous exercise has been established beyond the shadow of a doubt. That said, the time interval to be respected subsequent to an ACS before safely adding HIIE to rehabilitation programs remains to be defined.

1.5.1

Brown JP, Clark AM, Dalal H, Welch K, Taylor RS. Patient education in the management of coronary heart disease. Cochrane Database Syst Rev 2011;12:CD008895

The effects of exercise and psychological support on patients with cardiovascular pathologies have already been submitted to meta-analysis performed by the Cochrane database, but this is the first Cochrane review specifically devoted to the effects of educational efforts on the morbi-mortality, the quality of life, and the medical costs incurred by coronary patients. The authors included 13 studies meeting the inclusion criteria, namely randomized controlled trials dealing with adult heart disease patients in which the main intervention was essentially educational, with at least 6 months of follow-up, and with publication having occurred after 1990. Thirteen trials involving 68,556 patients were included, with follow-up ranging from 6 to 60 months and interventions ranging from two simple clinic visits to 4-week residential programs with review sessions during an 11-month follow-up. The different interventions were essentially compared with the usual medical care programs. The authors did not find any effect on total mortality, cardiac events (coronary syndrome relapse, revascularization) or hospitalizations. Most of the studies reported improvement with regard to assorted quality of life aspects, but they provided no proof of the “across-the-board” superiority of educational intervention. Medico-economic analysis was rendered difficult on account of the need for comparison of the different currencies involved over different years, but it appears to show from an overall standpoint, this type of intervention is likely to be cost-effective. These results differ from those of the meta-analysis carried out in 2005 by Clark et al., and the respective studies differ in ways rendering them hard to compare. Clark et al. studied the impact of educational interventions on total mortality and coronary syndrome recurrence and found a significant effect in the 23 studies they considered. Brown et al. put forward some hypotheses meant to explain their results: a generally short follow-up period yielding a relative lack of analytical power on account of the limited number of events. The authors nevertheless recognize that rehabilitation programs should include educational interventions of which the efficacy with regard to smoking, diet, blood pressure and overall health awareness is now commonly admitted. To sum up, the effects of these disparate initiatives deserve to be confirmed by applying “hard” criteria. Moreover, it appears that the degree of effect on total mortality (RR lowered by 25%) and morbidity (RR lowered by 17 to 42%) is clinically relevant, especially with regard to coronary diseases, given their high prevalence. These observations once again show how difficult it may be to connect the data provided by meta-analyses of which the results may vary in accordance with the inclusion criteria and periods, the parameters studied and the reality of clinical practice most ideally associating the three types of intervention: exercise, education and psychobehavioral support.

1.5.2

Pinto BM, Goldstein MG, Papandonatos GD, Farrell N, Tilkemeier P, Marcus BH, et al. Maintenance of exercise after phase II cardiac rehabilitation: a randomized controlled trial. Am J Prev Med 2011;41(3):274–83

Given the generally low physical activity adherence among patients having undergone a CR stay, it appears important to implement a strategy designed to combat the sedentary lifestyle to which an overwhelming majority of patients revert following hospital discharge, notwithstanding the functional awareness program and their newly acquired sensitivity to the importance of physical activity. This study is aimed at measuring the effectiveness of standardized home-based exercise counseling delivered over the phone, which is derived from a transtheoretical model and associated with use of an accelerometer ( n = 64). Results are compared with those registered by a control group ( n = 66) benefiting from neither support nor feedback. They show that intervention over the phone indeed helps patients to maintain some degree of physical activity (measured at 0, 6 and 12 months), to prevent negative behavioral changes and to increase effort tolerance . The study consequently underscores the importance of post-hospitalization follow-up allowing patients to durably maintain the positive effects of their stay, preventing future cardiac events, and thereby limiting the number of hospital readmissions. With regard to heart failure patients, Domingues et al. have reported conflicting results involving a small number of subjects ( n = 48); 3 months of telephone monitoring following an educational intervention during their stays in the hospital were relatively ineffective . Aside from the dissimilar population, it is worthwhile to note that the calls were indeed limited to monitoring, and the disappointing results serve to underline the motivational and psychobehavioral importance of actual maintenance counseling over the phone.

1.5.3

Houle J, Doyon O, Vadeboncoeur N, Turbide G, Diaz A, Poirier P. Innovative program to increase physical activity following an acute coronary syndrome: randomized controlled trial. Patient Educ Couns 2011;85(3):e237–44

In this study, Houle et al. dealt with ACS patients and assessed the effects of the five personalized discussions they had with a nurse in visits associating behavioral support and explanation pertaining to physical activity with use of a pedometer. After 1 year of follow-up, they reported a significant impact on average steps/day and waist circumference . The results of this study are in agreement with those reported by Moore et al., who set up a series of five 90-minute visits comprised of three during the hospital stay and two over the 2 months subsequent to hospital discharge and concomitantly showed that patients having undergone usual treatment were 76% more likely to discontinue physical activity within a year of discharge than the patients having benefited from the aforementioned intervention.

Whether it is a question of bringing activity into the daily lives of patients who have not benefited from a stay in the center or of maintaining the motivation of discharged patients with whom a multidisciplinary team has managed to instigate a new cycle of activity, it would appear that the new strategies, which include counseling, “exercise” visits, telephone monitoring and portable accelerometers, offer patients a number of opportunities to remain active. These types of interventions constitute a range of promising and inexpensive alternatives facilitating supervision of physical activity, especially during the maintenance stage, but they can in way replace a stay at a center.

1.5.4

Pavy B, Tisseau A, Caillon M. The coronary patient six months after cardiac rehabilitation: rehabilitation evaluation research (RER study). Ann Cardiol Angeiol (Paris) 2011;60(5):252–8

This work was aimed at studying the feasibility of a systematic follow-up interview focused on monitoring cardiovascular risk factors and on evaluating the results. This prospective open study was proposed to coronary patients admitted to the CR unit of the Machecoul center (Loire Atlantique) and residing within 50 km. The results show that this type of follow-up corresponds to both the wishes and the needs of the patients. Out of 229 eligible patients, only one refused to participate, while six were excluded from the study because they had discontinued the rehabilitation and 11 patients were not interviewed at 6 months (five for professional reasons, and six on account of a comorbidity). The interview also allowed for assessment of the effects of the program among the 202 patients finally included (mean age: 63.4 ± 10 years, 93% men, 17% subsequent to ACS, 23% subsequent to angioplasty and 75% subsequent to coronary bypass) and showed improvement as concerns the cardioprotective dietary score and the Ricci-Gagnon physical activity score (not validated in cardiac populations, but adapted to the needs of the study) and maintenance of functional walking capacities as evaluated by the 6-minute walk test. Moreover, the objectives of the relevant European recommendations were met in 70% of the patients with regard to LDL, in 64% with regard to arterial pressure, in 82% with BMI lower than 30 and in 36% with BMI lower than 25, in 67% as regards waist circumference (< 102 cm for men and 88 cm for women), and in 82% for non-smoking. Four non-fatal cardiac events and seven vascular events were reported. To conclude, this work offers a promising track in terms of monitoring and motivation, but given the short duration of the follow-up period and the probability that since the patients knew that they would be reevaluated at 6 months and improved their behavior accordingly (even if the improvement corresponded to a need), its findings require further confirmation. Moreover, recruitment bias existed insofar as the follow-up was proposed only to patients residing close to the center, even though travel time to the rehabilitation center seem likely to exert some influence on participation and has been known to have a negative effect on inclusion in rehabilitation programs . Finally, there is the question of the financial and human costs of this type of follow-up, and confirmation of its effectiveness may come to constitute an argument to be addressed to the authorities in view of developing “risk factor and exercise” follow-up visits at Phase III.

1.5.5

Cowie A, Thow MK, Granat MH, Mitchell SL. A comparison of home and hospital-based exercise training in heart failure: immediate and longterm effects upon physical activity level. Eur J Cardiovasc Prev Rehabil 2011;18(2):158–66

Since one of the factors affecting participation in rehabilitation programs is service availability and wait time , it would appear necessary to develop alternatives to the supervised programs taking place in a hospital center. This study was aimed at evaluating the effects of a hospital or home exercise training program on the amount of physical activity objectively measured by an activPAL™ monitor enabling discernment of lying, sitting and standing periods along with the counting of steps taken by the patient. Sixty patients (mean age 70 years, NYHA II/III, 51 men/9 women) were randomly divided into a group training at home (ED), a group training in a hospital structure (EH) and a control group (C). The actual training consisted in a 1-hour circuit-training program carried out two times a week, for 8 weeks. The patients wore on their thighs an activPAL™ device at baseline and at 8 weeks, and the patients in the two intervention groups wore it again, for 1 week, at 6 months. At 8 weeks, the patients in the EH group had significantly increased the number of steps taken in the framework of long-term walking and approximately corresponding to the continuous moderate efforts recommended, but the two programs had not led to other modifications in the amount of physical activity carried out. At 6 months, duration in the upright position had improved in the ED group, while the activity level had remained the same. The authors conclude that EH intervention allowed patients to walk over longer lapses of time, but it also appeared clinically relevant to note that at 6 months, a period of time during which patients frequently revert to inactivity and decline, activity had been maintained in both the ED and the EH groups. What is more, these results are congruent with those reported in the meta-analysis by Hwang et al. , who credited home exercise programs with positive effects as concerns the VO ₂ peak, training duration, distance covered in the 6-minute walk test, as well as quality of life and hospital admission rate. It should nonetheless be mentioned that this meta-analysis involved studies with small samples and short follow-up, and that they essentially included men classified NYHA II-III, while the intervention was generally compared to usual care.

1.5.6

Worringham C, Rojek A, Stewart I. Development and feasibility of a smartphone, ECG and GPS based system for remotely monitoring exercise in cardiac rehabilitation. PLoS One 2011;6(2):e14669

The Australian authors initially take note of the fact that notwithstanding enhanced awareness of the obstacles to participation in CR programs, which are undertaken by only around 30% of the clinically eligible patients in Australia, solutions resorting to new technology have failed up until now to take hold, even though they could facilitate more flexible monitoring. They have consequently developed a system allowing patients to follow a home-based program involving walking exercises during which ECG changes, speed and location are forwarded by a Smartphone to a secure server enabling real-time monitoring. The feasibility of this type of remote management was studied in six patients having presented with an ACS (mean age 53.6 years, mean BM 25.9 kg/m ² ) and who could not participate in a hospital-based program on account of distance and/or professional obligations. The program lasted 6 weeks and involved three walking sessions a week at an intensity determined on the basis of a 6-minute walking test, which was also monitored by a GPS system. The patients carried out 116 of the 134 scheduled sessions, in the majority of cases with no technical difficulties, the most frequently encountered problem being an occasional loss of GPS network coverage. No serious ECG event was reported, while two minor asymptomatic events (ST segment modification and supraventricular arrhythmia) rendered it necessary for a patient to be advised to suspend the exercises and consult a cardiologist, but finally without any therapeutic modification. The patients were satisfied with the system (main satisfaction rating: 4.8/5 points), finding it convenient and easy to expeditiously use (mean set-up and removal time: 3 minutes). From a clinical standpoint, improvement was observed as concerns distance covered, 6-minute walk test performance, the SF-36 physical component score and fewer symptoms of depression. Given today’s popularizing of Smartphones, it would seem particularly interesting to employ them in the development of projects meant to monitor physical activity and/or organization of therapeutic education programs with regard to diversified cardiac pathologies, and to analyze the cost–benefit ratio found in these types of approach.

1.5.7

Dilles A, Heymans V, Martin S, Droogne W, Denhaerynck K, De Geest S. Comparison of a computer assisted learning program to standard education tools in hospitalized heart failure patients. Eur J Cardiovasc Nurs 2011;10(3):187–93

One possible track in improved management of the continually more numerous heart failure population consists in employing multimedia technology. This study was consequently aimed at comparing the effects of a computer-assisted learning (CAL) program with those achieved through the usual educational approach (T) (written brochures and oral encouragement) in terms of knowledge (evaluated by the Dutch Heart Failure Knowledge Scale) and self-care behavior (evaluated by the European Heart Failure Self-care Behavior Scale) along with satisfaction (evaluated by a questionnaire specifically drawn up for the study). The two programs were carried out during periods of hospitalization. Thirty-seven patients were randomly divided into a CAL group ( n = 21) and a T group ( n = 16). There ensued significant improvement in terms of knowledge and of self-care at discharge and at 3 months in the two groups, without any difference between them. The CAL group patients did not encounter any major difficulties, and the rate of satisfaction was good. The authors draw the conclusion that it is necessary to develop further studies aimed at analyzing the effects of this approach in terms of morbi-mortality and hospital readmission in conjunction with the medico-economic aspects. In the short term, it would seem that this alternative may be legitimately proposed, when available, in addition to the usual care management procedures.

1.5.8

Wittmer M, Volpatti M, Piazzalonga S, Hoffmann A. Expectation, satisfaction, and predictors of dropout in cardiac rehabilitation. Eur J Cardiovasc Prev Rehabil 2011

This work was aimed at studying how often, for what reasons, and on account of what factors CR programs were prematurely discontinued, as well as the degree of satisfaction. The authors proceeded to an analysis of medical, demographic and psychosocial data with regard to a cohort of 2521 patients consecutively included in a Swiss cardiac rehabilitation program from 1999 until 2008 (coronary heart disease: 85%; valvulopathy: 15%; others: 10%; age: 59.7 ± 11.4 years; 85% men). The satisfaction level was evaluated at 75%. The authors took note of 305 “dropouts” (12.9%), including 39 for cardiac reasons (1.7%). There existed significant differences between the patients who quit and the patients who completed the program as concerns peak exercise capacity at the time of the initial effort or stress test (116 ± 41 vs. 123 ± 39 watts), body mass index (28 ± 7 vs. 27 ± 4 kg/m ² ), diabetes prevalence (18 vs. 13%), smoking (32 vs. 16%), professional status (24 vs. 34% remaining active), widowhood (8 vs. 3%), level of studies (37.5 vs. 46.4% with higher education), white collar occupation (21 vs. 27%), and scores on the quality-of-life scale. In multivariate analysis, the independent predictors of premature cessation included low exercise capacity, high BMI, smoking, diabetes, and lack of family supports. This work with a large-scale cohort confirms how important it appears, in view of enhancing compliance with CR programs, to pay particular attention to and provide supportive counseling for subjects presenting the above characteristics. It would probably also be necessary to study these different predictors in the framework of long-term compliance.

1.5.9

Evans RA, Singh SJ, Williams JE, Morgan MD. The development of a self-reported version of the chronic heart questionnaire. J Cardiopulm Rehabil Prev 2011;31(6):365–72

This work was aimed at studying the psychometric properties of the self-administered version of the Chronic Heart Questionnaire (CHQ), which may serve as a valid, reproducible and change-sensitive instrument in evaluation of the perceived general health status of heart failure patients. Fifty patients completed the self-reported and interview-led versions of the CHQ (CHQ-SR and CHQ-IL) at a 2-week interval in a random order, and 43 patients completed the CHQ-SR twice at a 2-week interval. Construct validity was evaluated in comparison with the Medical Outcomes Short Form 36 (SF-36), as was sensitivity to change (responsiveness) during a randomized trial comparing a CR program to the usual care procedures. The respective results of the two versions appear comparable, without any significant differences between the mean scores in each area. There nonetheless existed a slight improvement in the “emotional function” area from the first to the second completion of the SR version. There also existed moderate-to-high correlation between the different SR fields and the corresponding SF-36 components. As regards sensitivity to change, the two versions were comparable. In conclusion, this version appears to possess psychometric qualities comparable with those of the IL version, and it may prove to be particularly interesting and time-saving in studies evaluating quality of life and involving numerous patients.

1.5.10

Fornari L, Giuliano F, Pastana C, Vieira B, Caramelli B. Children first: how an educational program in cardiovascular prevention at school can improve parent’s cardiovascular risk. Eur Heart J 2011;32:972–3 [Abstract supplement]

In this work, which was presented at the ESC congress in Paris in August 2011, the authors studied the effects of an educational intervention on healthy lifestyle habits among Brazilian children receiving information on their parents’ supposed cardiovascular risk. Indeed, documents intended for their parents were distributed to all the children involved ( n = 197, corresponding to 323 parents, and in addition, the intervention group benefited of a one year multidisciplinary program on cardiovascular prevention adapted to their ages. At the beginning and at the end of the year-long intervention, the parents filled out a questionnaire pertaining to their dietary habits and physical activity, and the following measurements were noted down: weight, height, waist circumference, arterial blood pressure and laboratory test results. On inclusion, 9.3% (15 subjects) of the control group parents ( n = 161 parents, mean age = 39 years, 53.4% women) and 6.8% (11 subjects) of the intervention group parents ( n = 162 parents, mean age = 38 years, 55.5% women) presented with a 10-year cardiovascular disease risk greater than 10% according to the Framingham score. At 1 year, the risk dropped pronouncedly more in the intervention group (that is to say a 91% decrease, with just one parent at risk > 10%) than in the control group (that is to say a 13% decrease, with 13 parents still at risk > 10%) ( P = 0.0002; 95% CI: 0.001–0.195). Even though the study deals with primary prevention and involves children, it perfectly illustrates the well-founded nature of educational approaches addressed to other members of the family, as is the case with regard to spouses in the CR program, and aimed at durably modifying family lifestyle habits, which can not be dissociated from individual care and management.

1.6.1

Stanek KM, Gunstad J, Spitznagel MB, Waechter D, Hughes JW, Luyster F, et al. Improvements in cognitive function following cardiac rehabilitation for older adults with cardiovascular disease. Int J Neurosci 2011;121(2):86–93

This work was aimed at evaluating potential improvement with regard to cognitive impairment in patients benefiting from a CR program. Given their frequency and the fact that they are often misperceived, cognitive impairement have drawn particular attention over recent years when observed in patients with cardiovascular pathologies . Such deficits have been reported in numerous areas, including memory, attention, and the executive functions . Several explanatory hypotheses have been put forward: decreased cardiac output, low effort capacity, endothelial dysfunction, and decreased cerebral blood flow. Given the positive impact of CR with regard to these factors, it appears likely that CR would likewise have a positive impact on the cognitive functions. The authors consequently carried out an open study on 51 patients who had undergone 12 weeks of training (three sessions per week involving 1 hour of aerobic exercise in the form of circuit-training and 30 minutes of education). The following evaluations took place both before and after the program (at baseline and at discharge): (1) a battery of cognitive assessments: global (modified MMS); attention-executive functions (Trail Making Tests A and B; frontal assessment battery; letter-number sequencing); memory (Hopkins Verbal Learning Test: HVLT); brief visual memory test; delayed recall (recognition determination), language (Boston naming test short form), (2) treadmill stress test evaluation; (3) a transcranial Doppler test evaluating blood flow velocity in the middle and anterior cerebral arteries (36 out of the 51 patients). The authors took note of the existence of multiple cognitive impairments in 31% of the participants and also reported pronounced improvement of cognitive functions in all relevant areas with the single exception of language, lower blood flow velocity in the anterior cerebral artery alone, and marked improvement in exercise capacity (+2.7 METs). No association was found between the number of sessions attended and the aforementioned improvements. On the other hand, the authors found a correlation between improved exercise capacity and improved memory as tested by means of the HVLT. To sum up, there existed significant exercise capacity enhancement and ACA velocity diminution, but these factors do not appear to explain the cognitive improvements. What is more, the reported results should be interpreted cautiously since the population being studied was heterogeneous (post-ACS, post-heart surgery, heart failure, stable angina and/or high blood pressure), and the presence of depression, which might alter cognitive functioning, was not sought out prior to inclusion. The work nonetheless interestingly draws attention to the positive cognitive effects of CR, but it requires further confirmation, especially insofar as the underlying explanatory mechanisms remain to be elucidated. As pertains to these mechanisms, focus on cerebral oxygenation appears particularly promising; a study conducted by de Tournay-Jetté et al. on 61 elderly subjects having undergone a coronary bypass has shown that lowered preoperative cerebral oxygen saturation was definitely associated with the arrival of postoperative cognitive dysfunction. The same team has also demonstrated the benefits for these patients of postoperative cognitive training . As a result, impairment could quite probably be detected and subsequently managed through the optimal combination of exercise and cognitive training.

1.6.2

Haykowsky MJ, Brubaker PH, John JM, Stewart KP, Morgan TM, Kitzman DW. Determinants of exercise intolerance in elderly heart failure patients with preserved ejection fraction. J Am Coll Cardiol 2011;58(3):265–74

The objective of this work, which included 48 elderly heart failure patients with preserved ejection fraction (HFPEF) and 25 healthy age-matched control subjects, consisted in determining the physiological mechanisms accounting for reduced VO ₂ peak in these patients, who had not previously been studied with any degree of frequency. Left ventricular volumes (2D echocardiography), cardiac output (echocardiography), VO ₂ and arterial-venous oxygen content difference (calculated by the Frick equation) were measured at rest and during incremental ergocycle exercise in the two groups. In comparison with the healthy control subjects, the HFPEF patients showed a lower VO ₂ peak, which was associated with significantly lower cardiac output and arterial-venous difference. The strongest independent predictor of VO ₂ peak was the variation of the arterial-venous difference between rest and maximal effort ((a-v)O ₂ Diff reserve) in both the HFPEF patients and the healthy control subjects. Simultaneous cardiac output diminution and arterial-venous difference during effort significantly contribute to severe exercise intolerance in the HFPEF patients. The fact that the (a-v)O ₂ Diff reserve served as an independent predictor of VO ₂ peak suggests that peripheral, non-cardiac muscle-related factors are major contributors to exercise intolerance in these patients. In any event, this study confirms with regard to HFPEF subjects the results reported by Fu et al. on the importance of peripheral muscle considerations as explanatory factors for exercise intolerance. And the fact that HFPEF patients constitute at least 50% of elderly heart failure patients underscores the clinical interest of the questions being studied. Only subsequent work may determine what types of clinical intervention or what type of functional restoration program (aerobics/muscle strengthening) could maximally improve cardiac output and, particularly, muscular perfusion and muscle oxygen extraction in such a way as to maximally heighten the VO ₂ peak. Additional studies will indeed be necessary in a heart failure population that, up until now, has been virtually neglected.

1.6.3

Fu TC, Wang CH, Hsu CC, Cherng WJ, Huang SC, Wang JS. Suppression of cerebral hemodynamics is associated with reduced functional capacity in patients with heart failure. Am J Physiol Heart Circ Physiol 2011;300(4):H1545-55. Epub 2011 Jan 28

This work included 101 heart failure patients (NYHA II and III) along with 71 healthy control subjects and was aimed at studying the underlying physiological mechanisms accounting for exercise intolerance on this type of population. The authors simultaneously measured and compared cardiopulmonary (ventilatory) as well as central, muscle and cerebral hemodynamic responses during an incremental maximal exercise test employing a bicycle ergometer. The central hemodynamic responses were measured by cardiac bioreactance and the muscle and brain hemodynamic responses were measured by near-infrared spectroscopy (NIRS) at the level of the vastus lateralis and the left frontal lobe. The younger control subjects had higher central hemodynamic (cardiac output), peripheral (arterial-venous difference), cerebral and muscle [Oxy-hemoglobin (0 ₂ Hb) and total hemoglobin (THb)] levels during exercise than did the other groups (older control, heart failure class II). The central, peripheral, cerebral and muscle responses were weaker in the class III heart failure patients than in the class II heart failure patients and the older control subjects. Cardiac output along with cerebral and muscle responses (THb and O ₂ Hb) were positively correlated with the VO ₂ peak along with the oxygen-uptake efficiency slope and negatively with regard to the VE-VCO ₂ slope. The study demonstrates that a reduced cardiovascular response contributes to reduction of exercise tolerance in heart failure patients. The reduction of brain and muscle perfusion/oxygenation associated with exercise would consequently appear to result from reduced cardiac output and ventilatory inefficiency, particularly in class III heart failure patients. In clinical terms, it would appear that exercise intolerance in heart failure patients originates both centrally (cardiac output, cerebral hypoperfusion) and peripherally (arterial-venous difference, muscle hypoperfusion). Interventions such as interval training and muscle strengthening aimed at optimally improving cardiac output, cerebrovascular functioning and peripheral muscle use should be privileged with regard to heart failure patients in view of reducing their exercise intolerance and enhancing their quality of life.

1.6.4

Fu TC, Wang CH, Lin PS, Hsu CC, Cherng WJ, Huang SC, et al. Aerobic interval training improves oxygen uptake efficiency by enhancing cerebral and muscular hemodynamics in patients with heart failure. Int J Cardiol 2011 Dec 22. [Epub ahead of print]

Abnormal ventilatory and hemodynamic responses to exercise commonly contribute to diminished functional capacity in heart failure patients. This study was aimed at measuring the effects of interval training (IT) and continuous training (CT) on ventilatory efficiency along with central, muscle and cerebral hemodynamic responses in heart failure patients. Forty-five heart failure patients were randomly divided into an interval training group (IT: 3-minute intervals at 80% of VO ₂ peak, followed by 3 min at 40% of VO ₂ peak for 30 min), a continuous training group (CT: 30 min at 60% of VO ₂ peak) and a control group (CG). Cardiac output was measured by cardiac bioreactance and muscle and cerebral O ₂ perfusion-extraction by near-infrared spectroscopy (NIRS) at the level of the vastus lateralis and the left frontal lobe. Following 12 weeks of intervention, the IT group showed more improvement in terms of the oxygen-uptake efficiency slope and the VE-VCO ₂ slope than did the CT ad CG groups. Moreover, only the IT group (and not the CT group) boosted its cardiac output and its muscle and cerebral O ₂ perfusion-extraction during the exercise period. Multivariate analyses have shown that cardiac output is the main predictor of VO ₂ peak and that cerebral and muscle THb are associated with the oxygen-uptake efficiency slope. Moreover, significant diminution of brain natriuretic peptide (BNP), myeloperoxidase and interleukin-6 levels along with higher quality of life scores (SF-36 and Minnesota Living with Heart Failure) have been demonstrated. Interval training (IT) would consequently appear to increase ventilatory efficiency and exercise tolerance while improving central and peripheral (cerebral and muscle) hemodynamics in the heart failure patient. What is more, IT diminishes the oxidative stress and inflammation associated with heart failure and enhances the quality of life of the concerned population. From a clinical standpoint, this study entails important repercussions with regard to heart failure management and exercise retraining for heart failure patients. It also confirms the superiority of IT in comparison to CT , of which the effects in the context of the study were distinctly limited. IT should consequently be preferred in a heart failure population so as to optimally enhance quality of life while significantly limiting oxidative stress and inflammatory manifestations. This type of training is particularly effective in improvement of ventilatory efficiency (lessened shortness of breath) as well as perfusion of peripheral cerebral and muscle tissues. The encouraging results have yet to be confirmed in more sizable cohorts, and it remains to be seen whether improved cerebral perfusion will be reflected in improved cognitive function in the impaired heart failure patient.

1.7.1

Cacciatore F, Abete P, Mazzella F, Furgi G, Nicolino A, Longobardi G, et al. Six-minute walking test but not ejection fraction predicts mortality in elderly patients undergoing cardiac rehabilitation following coronary Q8 artery bypass grafting. Eur J Cardiovasc Prev Rehabil 2011 Sep 20. [Epub ahead of print]

In patients having undergone coronary artery bypass grafting (CABG), age may possibly help to determine the possibility of predicting mortality on the basis of 6-minute walk test performances or the ejection fraction. Wishing to answer the question, the authors monitored 882 patients who had undergone CR subsequent to CABG, and they were stratified into two sub-groups: adults (< 65 years) and the elderly (> 65 years). Ejection fraction on admission to rehabilitation was respectively 52.6 ± 9.1% and 51.3 ± 8.9% in patients under and over 65 years of age, and the distances covered during the 6-minute walk test were respectively 343.8 ± 93.5 m and 258.9 ± 95.7 m ( P < 0.001). Mean follow-up was 42.9 ± 14.1 months, with a mortality rate of 8.2% in the adults and 10.9% in the elderly (non-significant difference). Regression analysis showed that ejection fraction higher than or equal to 50% and a performance higher than or equal to 300 m in the 6-minute walk test carried out at the beginning of CR appeared to be associated with lower mortality for the group taken as a whole. On the other hand, while ejection fraction was apparently “protective” in those under 65, that was not the case with those over 65, even though a distance of greater or equal to 300 m was associated with lessened mortality in the elderly subjects. Consequently, these two parameters would appear to independently protect bypass patients entering a rehabilitation program, with an association between more distance in the 6-minute walk test and lessened mortality in the most aged. These results serve to confirm the absence of strict parallels between on the one hand objective clinical parameters such as ejection fraction and mortality rate, and on the other hand the interest of the 6-minute walk test, bearing in mind that similar conclusions had already been drawn in older works exclusively focused on heart failure patients . The interest of the walking test as a prognostic factor had not previously been studied with any frequency in cardiac pathologies, even though it may be performed soon after sudden cardiac arrest (SCA) . This test is directly connected with aerobic capacities, and its intensity is in approximate correspondence with that of the ventilatory threshold in coronary patients and with a rate of perceived exertion (RPE) of 14 on the Borg scale .

1.7.2

Gremeaux V, Troisgros O, Benaim S, Hannequin A, Laurent Y, Casillas JM, et al. Determining the minimal clinically important difference for the six-minute walk test and the 200-meter fast-walk test during cardiac rehabilitation program in coronary artery disease patients after acute coronary syndrome. Arch Phys Med Rehabil 2011;92(4):611–9

The minimal clinically important difference (MCID) is a concept defined as “the smallest difference in a score that patients perceive as beneficial and that would lead, in the absence of harmful side effects or excessive costs, to adaptations in care management”. MCID differs from the minimal detectable change, which indicates the amount of change necessary to exceed the measurement error. When interpreting clinical measurements, it matters to consider that even though small changes may be statistically significant, they are not necessarily clinically relevant. By using two methods, one of them subjective and the other objective (based on performance distribution) in walk tests repeated every 2 weeks during a rehabilitation program involving 81 stable coronary patients (58.1 ± 8.7 years), the authors showed that the MCID was comparable to the one reported by Holland et al. for chronic obstructive pulmonary disease patients . The mean variation in the distance covered in the 6-minute walking test was −6.5 m for patients perceiving no improvement, as opposed to +23.3 m for those who perceived improvement in their walking capacities ( P < 0.001), a finding that was congruent with the distribution-based method of calculating the MCID (23 m). The threshold level of 25 m had positive or negative predictive value of 0.9 and 0.63 in detection of patients having perceived improvement. These figures were not in agreement with an MCID taking into account the judgment of the physiotherapist having supervised the training sessions. A distance of 25 m would consequently appear to be the minimal threshold allowing an intervention to be considered as providing an improvement that would be clinically perceptible by the patient and thereby enable the therapist to effectively interpret functional progress. Moreover, awareness of this threshold is helpful when calculating the number of subjects needed for clinical trials in which the 6-minute walk test constitutes one of the endpoint. For example, in order to show a predictable difference over 25 m between two groups, with a risk α and β of 5%, it would appear necessary to include 40 subjects in each group.

1.7.3

Gremeaux M, Hannequin A, Laurent Y, Laroche D, Casillas JM, Gremeaux V. Usefulness of the 6-minute walk test and the 200-metre fast walk test to individualize high intensity interval and continuous exercise training in coronary artery disease patients after acute coronary syndrome: a pilot controlled clinical study. Clin Rehabil 2011;25(9):844–55

International recommendations pertaining to the intensity of exercise sessions for coronary patients vary considerably, ranging from 50 to 80% of maximal exercise capacity . Determination of a target heart rate is the most widely and routinely used method in France since it is simple, necessitates only minimal equipment (heart rate monitor or manual pulse-taking), and allows the patient autonomy in effort management. It is consequently common practice to recommend the performance of continuous exercises at a heart rate corresponding to the one observed at the ventilatory threshold (VT) during exercise testing. On the other hand, the effects of some medications, particularly negative chronotropes, and the phenomenon of cardiac drift may lead to underestimation of optimal intensity . Moreover, VT determination necessitates analysis of respiratory gas exchanges, which in turn necessitates consequential human and material resources. As a result, the target heart rate is frequently calculated from equations based on the maximum heart rate observed during the exercise test. These equations have only rarely been validated in coronary patients, and French studies have shown that application of the widely employed Karvonen Formula may eventually lead to the “undertraining” of coronary patients . In another study, the same team has shown that prescription for training on the basis of intensity as subjectively perceived on the Borg scale definitely leads patients to higher intensity than during the sessions prescribed at the VT heart rate, though remaining safe . Given this finding, the authors tested a training prescription methodology based on the heart rate observed during the walking tests carried out at the onset of rehabilitation, and they postulated that these tests could combine the respective advantages of objective indicators (heart rate) and subjective indicators (regulation of walking speed by the patients themselves). Three training modes were thence tested in 27 stable coronary patients: (A) continuous training at 70% of the maximal exercise test heart rate ( n = 10); (B) continuous training at the heart rate observed at the end of the 6-minute walk test, which roughly corresponds to VT heart rate ( n = 8) and (C) interval training with 2-minute peak work periods at the heart rate noted at the end of the 200-m fast walk test, which corresponds to approximately 85% of the maximal heart rate ( n = 9). The results show significant ( P < 0.05) and comparable improvement of walking capacities in the three groups. Improvement of the VO ₂ peak (indirectly determined) was significantly more pronounced in group C than in group A. What is more and with regard to the continuous training modes, the patients trained on the basis of the 6-minute walk test heart rate were on the average closer to target heart rate during the rehabilitation sessions than those trained at 70% of maximal heart rate. This pilot study has its limitations (small sample of patients with relatively high capacities, total work differing from one group to the next) but is nonetheless in agreement with the data from the literature pertaining to the superiority of high-intensity interval training in these types of patients and demonstrating the interest of using indicators other then maximum heart rate in the exercise test or at the VT . In fact, the interest of this kind of training prescription individualization had already been underlined in older work on the elderly , and it was recently confirmed by a French team with regard to cystic fibrosis patients . To conclude, and with all else being equal from an efficiency standpoint, one may deem it worthwhile to choose modes that are more functional than theoretical, easier to implement without a technically complex environment, comparably easy to readjust and with respect to which, patients are as close as possible to the stated objectives. Walking tests would appear to more than adequately meet these requirements, which could be particularly interesting for phase three patients (after the rehabilitation phase) pursuing supervised activity in “cardiac health club” associations lacking the material means that would allow them to reassess maximal capacities in a medical setting.

1.7.4

Massucci M, Perrero L, Mantellini E, Petrozzino S, Gamna F, Nocella A, et al. Cardiorespiratory comorbidity: a new challenge for physical and rehabilitation medicine specialist. Eur J Phys Rehabil Med 2012;18(2):126-33. Epub 2011 Nov 25

This work had two main goals: (1) to assess the frequency of cardiorespiratory comorbidities in Italian rehabilitation units admitting patients presenting with motor disorders of orthopedic or neurological origin and (2) to evaluate the impact of these comorbidities on the outcomes of the rehabilitation programs proposed to these patients. A questionnaire sent out to 33 units indicated length of hospital stay, need for transfer to acute care units, degree of satisfaction of the therapists as concerns the functional recovery of patients presenting with cardiorespiratory comorbidities. Sixteen units responded satisfactorily, allowing for analysis of the data pertaining to 909 patients, with large-scale incidence of cardiovascular and respiratory pathologies (61.5%). Length of stay was significantly higher for these patients than for those without the comorbidities (46.5 ± 21 d vs. 37.3 ± 19 d), as was rate of transfer to acute wards (8.62% vs. 2.44%). Sixty-nine percent of the physicians questioned said they were “quite satisfied” with regard to the functional recovery of the patients with cardiorespiratory morbidities. What is more, the sub-group composed of neurology patients with cardiorespiratory pathologies presented a score significantly lower on the Functional Independence Measure (FIM) scale at admission compared to the patients without comorbidities (55.4 ± 20.6 vs. 73.7 ± 22.1). At discharge, however, there existed no significant FIM score difference between these two sub-groups. At a time when exercise retraining is being proposed with regard to an increasing number of incapacitating chronic pathologies including some that up until recently occasionally entailed exercise contraindications, this work underlines the extent to which cardiorespiratory pathologies exert a negative impact on length of stay and transfer to acute care of neurological and orthopedic patients, albeit with apparently little or no negative impact on functional outcome. It would consequently appear fundamental that the rehabilitating physician acquires at least minimal skills in the management and prescription of exercise that can have a favorable effect on the clinical evolution of associated comorbidities, and possibly minimize length of stay and incidence of acute complications.

1.8.1

Jones WS, Clare R, Ellis SJ, Mills JS, Fischman DL, Kraus WE, et al. Effect of peripheral arterial disease on functional and clinical outcomes in patients with heart failure (from HF-ACTION). Am J Cardiol 2011;108(3):380–4

This ancillary study by HF-Action constitutes a comparison of usual care vs. training + usual care over 1 year in heart failure patients with left ventricular ejection fraction less than 35% (NYHA II-IV), some of whom also presented with peripheral arterial disease (PAD), with the degree of influence of this type of comorbidity on clinical and functional outcome being poorly known. Among the 2331 patients included by HF-Action, 157 (6.8%) presented with PAD. At baseline and in comparison with non-PAD patients, they were characterized by shorter exercise test duration (8 vs. 9.8 minutes), a lower VO ₂ peak (12.5 vs. 14.6 mL/kg per minute) and less distance covered during the 6-minute walking test (306 vs. 371 m). At 3 months, PAD patients showed less improvement in the exercise test (duration: +0.5 vs. +1.1 minutes) and moderate improvement as concerns the VO ₂ peak (+0.1 vs. 0.6 mL/kg per minute). Even afer adjustment for age, smoking or non-smoking, ischemic origin of the heart failure, and presence or absence of diabetes, the difference remained significant. PAD presence was shown to be an independent predictor of all-cause death and hospitalization. This work has limitations insofar as it constitutes an a-posteriori analysis of a study of which the initial design was not conceived as to test this hypothesis, and the population studied may not have been representative. What is more, PAD prevalence was probably underestimated on account of having been limited to symptomatic cases since diagnosis was established on the basis of a dossier rather than a clinical or complementary examination. In practical terms, these data suggest the interest of screening by means of a simple test such as measurement of the systolic pressure index in view of detecting heart failure patients with a particularly unfavorable prognosis and of possibly customizing the exercise prescription for patients benefiting from rehabilitation. One must not forget that in this population, medication-based alternatives appear limited, the FDA having warned against use of phosphodiesterase inhibitors (Cilostazol) in heart failure patients.

1.8.2

Villemur B, Marquer A, Gailledrat E, Benetreau C, Bucci B, Evra V, et al. New rehabilitation program for intermittent claudication: Interval training with active recovery: pilot study. Ann Phys Rehabil Med 2011;54(5):275–81

In this prospective study, the authors tested the hypothesis according to which, interval training associating a period of non-maximal intensity exercise (70% of the patient’s maximal walking capacities) with a period of active recovery (40% of the patient’s maximal walking capacities) may combine the benefits of the high intensity reached during the effort phase with those stemming from low-intensity muscle activity characterizing the recovery phase. Eleven patients presenting with PAD (mean age: 68.3 years) underwent two weeks of treadmill training with two daily 30-minute sessions of increasing intensity. Each session consisted in a succession of five six-minute cycles, with 3 minutes of active effort followed by 3 minutes of active recovery. The training was associated with muscle strengthening exercises above and below the level of stenosis, with global gymnastic exercises and intermittent pressotherapy. All the patients completed the protocol without incident and said they were satisfied with the management. The walking distance covered significantly improved, increasing from 610 m on the average at the outset of the program to 1252 m at the end. This pilot study consequently provides a rational starting-point for an ambitious clinical trial, since the first-line treatment of intermittent arterial claudication is actually, in the absence of threatening injuries or cardiac contraindications, a form of reeducation . That much said, the most effective intensity for efforts involving the lower limbs has yet to be agreed upon, nor has the question of whether or not provocation of muscle ischemia (claudication, cramp) should take place during reconditioning.