Cardiac rehabilitation

Physiotherapists are valuable members of the multi-disciplinary cardiac rehabilitation team. This chapter provides important key information about the research evidence, exercise prescription and planning across the four phases of cardiac rehabilitation. For in depth information about planning and delivering exercise rehabilitation for special conditions such as patients with heart failure, implanted cardioverter-defibrillators and cardiac transplantation, the reader is advised to refer to the guidelines and texts listed at the end of the chapter.

Background

According to the World Health Organization (WHO), an estimated 17 million people die of cardiovascular disease (CVD) every year of whom 7.2 million die of coronary heart disease (CHD) and 5.7 million die of stroke. CVD is responsible for 10% of disability adjusted life years (DALYs) lost in low- and middle-income countries and 18% in high-income countries.

According to 2008 statistical data from the British Heart Foundation (BHF), CHD causes around 88,000 deaths in the UK every year. It is also the most common cause of premature death (death before the age of 75) in the UK. Eighteen per cent of premature deaths in men and 9% of premature deaths in women are from CHD. Nearly all deaths from CHD are a result of myocardial infarction (MI, heart attack). Around 124,000 people in the UK suffer a MI every year. There are 28,000 new cases of angina and 27,000 new cases of heart failure every year in the UK.

Over the last two decades of the twentieth century in the UK, there was a decline in the death rates from CHD. In a study by Unal et al. (2004), the authors concluded that 58% of CHD mortality decline in the 1980s and 1990s was owing to a reduction in major risk factors, primarily smoking. The remaining 42% of the decline in mortality was explained by treatments, including secondary prevention.

There remains considerable variation in the death rates across the UK. Deaths from CHD are highest in Scotland and the north of England. While deaths from CHD have declined overall, the difference between the most deprived groups and the least deprived groups remains high (5 : 1). South Asians living in the UK (Indians, Bangladeshis, Pakistanis and Sri Lankans) have a higher premature death rate from CHD than average. The death rate is 46% higher in South Asian men and 51% in South Asian women.

The overall burden of CVD is now far greater as a result of more people surviving cardiac illnesses and living much longer than before.

While genetic factors play a part, 80–90% of people dying of CHD have one or more major risk factors influenced by lifestyle. Physical activity, obesity, smoking and diabetes are major risk factors for CHD.

Many people find making significant lifestyle changes difficult, for example, people may be addicted to nicotine. If someone recently admitted to hospital with CHD needs to increase the amount of physical activity they undertake regularly, not only do they need to be well motivated but they and their families need to be confident that the exercise is safe.

Like all major illnesses, CHD has major physical, psychological and behavioural impacts on patients and their families. For some, the psychological consequences can be persistent and disabling. They can also be a barrier to making the lifestyle changes necessary to reduce the subsequent cardiac risk. For example, people with CHD can be afraid to take exercise or participate fully in their daily activities for fear of damaging their heart. After admission to the hospital, maybe following a MI or for coronary revascularisation, the advice and treatment provision in primary care may not always be sufficient. Many people require more intensive help to understand their illness and treatment to attain the lifestyle changes and to regain their confidence so that they can enjoy the best possible physical, mental and emotional health, and return to as normal a life as possible.

What is cardiac rehabilitation?

The WHO defines cardiac rehabilitation as:

The rehabilitation of cardiac patients is the sum of activities required to influence favourably the underlying cause of the disease, as well as the best possible physical, mental and social conditions, so that they may, by their own efforts, preserve or resume when lost, as normal a place as possible in the community. Rehabilitation cannot be regarded as an isolated form of therapy, but must be integrated with the whole treatment, of which it forms only one facet.

(WHO 1993)

Cardiac rehabilitation is a comprehensive intervention that offers education, exercise and psychosocial support for patients with CHD and their families and is delivered by many specialist health professionals. Cardiac rehabilitation can promote recovery, enable patients to achieve and maintain better health, and reduce the risk of death in people who have heart disease.

Definition

Cardiac rehabilitation is the process by which patients with cardiac disease, in partnership with a multidisciplinary team of health professionals, are encouraged and supported to achieve and maintain optimal physical and psychosocial health.

BACPR (2002)

Research evidence for cardiac rehabilitation

When well provided and when people are offered comprehensive and tailored help with lifestyle modification involving exercise training, education and psychological input, cardiac rehabilitation can make a substantial difference in reducing mortality by as much as 20–25% over three years.

The Cochrane Review 2004 (Jolliffe et al. 2004) (Table 8.1) established the importance of exercise-based cardiac rehabilitation. Cardiac mortality was reduced by 31% in the exercise-only cardiac rehabilitation and by 26% in comprehensive cardiac rehabilitation groups.

Table 8.1

Cochrane review 2004:
meta-analyses of 8440 myocardial infarction, revascularisation and ischaemic heart disease patients

Exercise-only rehabilitation	27% reduction all cause mortality 31% reduction in cardiac mortality
Comprehensive rehabilitation	13% reduction all cause mortality 26% reduction cardiac mortality

The research has been focussed around phase III of rehabilitation and in patients after MI and revascularisation.

Many studies still include only low risk, male, Caucasian, middle-aged MI patients and enroll only a small number of women, the elderly and ethnic minorities. Other cardiac patient groups, such as those following cardiac surgery, heart failure or heart transplantation, are excluded, thereby limiting the generalisability of the results.

Systematic reviews for chronic heart failure have demonstrated that exercise-based cardiac rehabilitation reduces mortality, increases the quality of life and that exercise is safe in this group of patients.

Evidence for physical activity and exercise

The WHO estimates that around 6% of all disease burden and around 30% of CHD burden to be caused by physical inactivity (WHO 2010). Physical activity levels are low in the UK. The Health Survey for England data (2008) show that only 39% of men and 29% of women meet the government guidelines of 30 minutes of moderate physical activity five or more times a week. The proportion of both men and women who met the recommendations decreased with age. Therefore, structured exercise as a therapeutic intervention is essential to the cardiac rehabilitation programme.

Women

Incidence of CHD tends to be higher in men; however, this difference decreases with increasing age. According to the BHF statistics 2010 (BHF 2010), every year 44,000 women in the UK have a MI. Uptake of cardiac rehabilitation among women is low. When women attend cardiac rehabilitation programmes, the outcomes are as good as, or better than, for men. Their need may be greater as they suffer greater loss of function in relation to return to work, activity and sexuality, and experience high levels of anxiety and depression. More gender-specific information, individualised and flexible programmes, and suitable environment are required to address the specific needs of this group.

Older adults

Over half of all MIs occur in people over the age of 70 years and this is going to rise further as the number of older people in the total population increases. Disability rates are very high in these patient populations, particularly in women and in patients with angina or chronic heart failure. The presence of depression is also a determinant of poor physical functioning. Cardiac rehabilitation has been demonstrated to be safe and to improve aerobic capacity and muscle strength in older adults. Elderly people can derive similar benefits from a comprehensive menu-based cardiac rehabilitation programme. Issues of access, transport, timings and flexible programmes need to be addressed to meet the requirement of this patient population.

Ethnic groups

The incidence of CHD is much higher in some ethnic communities (e.g. South Asians). It has been suggested that people from ethnic minorities are less likely to be referred and join cardiac rehabilitation programmes. While planning strategies for rehabilitation for ethnic groups, their heterogeneity and cultural and linguistic needs must be acknowledged. When a behavioural change is required, it is crucial that the message is clearly understood. Knowledge of the cultural influences on physical activity and dietary practices would be beneficial to the patient. Similarly, awareness of health education material in appropriate languages can enhance the quality of service. It will help to involve health professionals from similar cultural backgrounds to develop and evaluate progress.

A variety of settings appropriate to the targeted communities can be used, for example community centres, temples, mosques, churches, health centres, etc. Involvement of the family and the younger generation is vital.

Other groups

For these groups, individualised assessment and risk stratification is essential.

Cardiac transplant

This group is relatively small. There is some evidence that exercise-based cardiac rehabilitation improves exercise tolerance in this group of patients.

Valve surgery

Supervised exercise training in comprehensive cardiac rehabilitation is beneficial in improving functional capacity, reducing symptoms and improving the quality of life in this patient group.

Congenital heart disease

This group includes young people and children. Supervised exercises improve exercise capacity and psychological function in this patient group.

Implanted cardioverter-defibrillators

The number of patients with implanted cardioverter-defibrillators in a cardiac rehabilitation programme may be small; however, comprehensive cardiac rehabilitation is safe and improves exercise ability and psychological well-being significantly.

Provision in the UK and cost-effectiveness

The overall level of provision of cardiac rehabilitation programmes in the UK has increased rapidly in the last 20 years. Current data from the National Audit of Cardiac Rehabilitation reveal the number of programmes at 395. The national service framework for CHD has advocated the use of disease registers in primary care to provide long- term follow up of patients with CHD and has set standards and milestones for secondary prevention.

There are huge variations in programme types, duration, frequency and intensity of exercise training. Many centres are delivering the service in primary care, and menu-based programmes are provided by a multi-disciplinary team.

A UK estimate suggests a cost of £6900 per Quality Adjusted Life Years (QALY) and a cost per life year gained of £15,700 three years after cardiac rehabilitation. This offers good value compared with many other treatments currently provided by the National Health Service (NHS).

Components of cardiac rehabilitation

• Risk factor assessment and modification.

• Education.

• Exercise.

• Psychosocial support.

Operation and delivery

It transpires that cardiac rehabilitation is really a continuum of care from the time the patient is admitted until discharge and extends to outpatient care, as well as long-term follow-up in the community. Patient care is shared with the cardiology team, of which cardiac rehabilitation forms an essential part. Cardiology management includes patient assessment and risk stratification (predicting the likelihood of recurrence of cardiac events and disease prognosis). The patient also undergoes diagnostic tests and drug therapy, and may need revascularisation, such as angioplasty or a bypass grafting as appropriate.

Traditionally, cardiac rehabilitation is divided into four phases, progressing from the acute hospital admission stage to long-term maintenance of lifestyle change.

Phase I: inpatient period.

Phase II: early post-discharge period.

Phase III: supervised outpatient programme, including structured exercise.

Phase IV: long-term follow-up/maintenance in primary care.

Phase I: Inpatient period

Cardiac rehabilitation is offered as soon as it is practical as an integral part of care to someone who is admitted (or who is planned to be admitted) to hospital with CHD. It includes:

• assessment of physical, psychological and social needs;

• negotiation of a written informal plan for meeting these identified needs;

• initial advice on lifestyle, e.g. smoking cessation, physical activity (including sexual activity), diet, alcohol consumption and employment;

• mobilisation;

• education about prescribed medication, its benefits and possible side effects;

• involvement of relevant informal carer;

• provision of locally written information about cardiac rehabilitation;

• discharge planning.

Phase II: Early post-discharge period

This service shows variation in different regions and can vary from as little as a telephone helpline to group sessions or individual appointments (Figure 8.1). The National Service Framework recommendation includes:

Figure 8.1 Assessment with cardiac nurse.

• comprehensive assessment of cardiac risk, including physical, psychological and social needs for cardiac rehabilitation, and a review of the initial plan to meet these needs;

• provision of lifestyle advice and psychological interventions according to the agreed plan by the multi-disciplinary team;

• maintaining involvement of relevant informal carer;

• home visits, if appropriate.

Phase III: Supervised outpatient programme, including structured exercise

Traditionally, this phase is well set up in the form of an outpatient hospital-based programme, although more services are now shifted into primary care. It includes:

• risk stratification and identification of the high-, medium- and low-risk patient for exercise;

• individualised progressive exercise prescription and supervised exercise sessions which vary from 4–12 weeks in different regions;

• re-evaluation of risk factors for CHD and health promotion advice and education (Figure 8.2).

Figure 8.2 Physiotherapist measuring the height to assess body mass index.

• psychosocial interventions, such as stress management, counselling and vocational guidance.

Phase IV: Long-term follow-up/maintenance in primary care

This phase is now well set up in many districts, with emphasis on provision of exercise sessions available in community or leisure centres. Specialist training to exercise CHD patients in the community is available to the exercise instructors by the British Association for Cardiovascular Prevention and Rehabilitation (BACPR).

Phase IV includes:

• long-term maintenance of individual goals;

• professional monitoring of clinical status and follow-up of general progress;

• ongoing psychosocial support and support groups.

Cardiac rehabilitation team

The cardiac rehabilitation package individualised for each patient requires expertise and skills from a multi-disciplinary collaborative team of professionals (Figure 8.4). The team includes a cardiologist and staff from nursing, physiotherapy, dietetics, pharmacy, occupational therapy and psychology with training in cardiac rehabilitation. Continuation of care in the community involves the primary healthcare team that is the general practitioner and cardiac nurse, phase IV exercise specialist and a link from a local cardiac patient support group (Figure 8.3).

Figure 8.3 Dietician addressing a group of patients attending phase III cardiac rehabilitation programme.

The role of the physiotherapist

Physiotherapists have the knowledge, assessment skills and clinical reasoning, combined with evidence-based approach to treatment, to undertake the rehabilitation management of patients with multi-pathology problems. Physiotherapists are also trained to run group sessions and classes. Hence, the role of the physiotherapist within the multi-disciplinary team should focus on exercise prescription, training and education in phases I–III. The modification in exercise prescription needs to be discussed with medical and nursing team members. In a group setting where exercise is delivered to CHD patients, teamwork and liaison with other team members who are aware of patients’ clinical and psychosocial issues is essential.

Professional development

The Association of Chartered Physiotherapists in Cardiac Rehabilitation (ACPICR) recommends that physiotherapists wishing to specialise in this area should refer to the ACPICR competences for the exercise component of phase III cardiac rehabilitation and the Skills for Health: Coronary Heart Disease document (ACPICR 2008). They should consider undertaking professional development in exercise physiology and exercise prescription in cardiovascular disease. Use of clinical and cardiac networks to share experiences, for example interactive CSP (www.csp.org.uk), is recommended.

Benefits of exercise training

Definition

The term ‘exercise training’ applies to a programme of repeated exercises undertaken at a guided or prescribed intensity and frequency over a period of time, usually several weeks. It is based upon aerobic exercise designed to improve physical performance at both maximal and submaximal levels. It may be of low, moderate or high intensity, and may also include resistance training.

Research confirms that exercise training improves physical performance (exercise tolerance, muscular strength and symptoms), psychological functioning (anxiety, depression and well-being), and social adaptation and functioning in cardiac patients (Tables 8.2 and 8.4). It shows a reduction in mortality, morbidity, recurrent events and hospital readmissions. It is also found to have a positive impact on patients’ physical ability to exercise (Table 8.3). Therefore, exercise training as a therapeutic intervention is central to the cardiac rehabilitation programme.

Table 8.3

Symptomatic benefits of exercise training in chronic heart disease patients

Reduced risk of arrhythmias

Increased ischaemic threshold

Increased angina threshold

Improved coronary perfusion

Reduction in ST wave changes

Reduced angina episodes/shortness of breath

Table 8.4

Psychosocial benefits of exercise in chronic heart disease patients

Physiological adaptations to exercise training in healthy individuals and coronary heart disease patients

In healthy individuals physiological adaptations to aerobic exercise training are central (cardiac) and peripheral (skeletal muscle and vascular).

Adaptations at submaximal level of aerobic exercise

Adaptations at the submaximal level of aerobic exercise are reduction in heart rate (HR) owing to a decrease in sympathetic activity and increase in parasympathetic activity (vagal tone). The stroke volume increases owing to greater left ventricular filling and an increase in left ventricular mass. A decrease in the resting HR and blood pressure (BP) implies reduced myocardial oxygen demand. Also, the period of diastole is increased allowing greater time for blood to flow into the coronary circulation.

Cardiac output [CO = HR (heart rate) × SV (stroke volume)] must always match metabolic demand, but does so with reduced HR and increased stroke volume. Systolic BP (SBP) decreases and there is redistribution of blood flow to trained skeletal muscle and other tissues. Circulating catecholamines decrease and the arterio-venous oxygen difference increases.

Central changes as a result of aerobic exercise training

• Increased stroke volume.

• Increased left ventricular mass.

• Increased chamber size.

• Increased total blood volume.

• Decreased total peripheral resistance during maximal exercise.

Peripheral changes as a result of aerobic exercise training

• Increased arterio-venous oxygen difference.

• Increased number and size of mitochondria.

• Increased oxidative enzyme activity.

• Improved capillarisation.

• Increased myoglobin.

Key point

As a result of aerobic training there are functional and structural changes in skeletal muscle, the heart and the circulation. These changes improve the circulatory system’s capacity to transport oxygen to the working muscles (central changes) and the capacity of skeletal muscle to extract and use oxygen (peripheral changes).

Increase in VO_{2 max}

Oxygen consumption (VO₂) is expressed either in absolute terms as litres per minute (L.min⁻¹) or relative to body weight as mL per kg per minute (mL.kg⁻¹.min⁻¹). VO_{2 max} is the highest rate of oxygen consumption attainable during maximal exercise. Aerobic training increases VO_{2 max}.

In relative terms, an individual walking at 4 miles per hour uses 17.5 mL of oxygen per kg of bodyweight per minute. In absolute terms, a man weighing 70 kg will use 1225 mL or 1.2 L per minute.

Key point

The significance of increased VO_{2 max} is a reduction in physiological stress evoked by submaximal activity and not the ability to perform maximal bouts of exercise.

In CHD patients, the increase in VO_{2 max} is predominantly a result of peripheral adaptations. Central changes are associated with long periods of high intensity training. Although central changes have been shown with high intensity training in CHD patients in some studies, in the conventional cardiac rehabilitation programmes this regime is not suitable. Physical performance improvements are better seen in patients with low exercise tolerance.