Chronic Refractory Angina

Cardiac Rehabilitation for Refractory Angina:
part 1 (authors)

The World Health Organisation¹ has summarised the medical goals of cardiac rehabilitation (CR) as;

• the prevention of early cardiac mortality

• a decrease in cardiac morbidity, e.g. reduced incidence of myocardial infarction (MI) and coronary artery bypass graft (CABG) closure,

• relief of symptoms such as angina and breathlessness.

The evidence strongly suggests that it can meet all of these aims. Meta-analyses of randomised trials of CR have shown reduced mortality of 20-25% and improvements in morbidity^2,3.

Numerous systematic reviews have been conducted and have endorsed its benefits. For example, the US National Heart Lung and Blood Institute reviewed the evidence for CR as secondary prevention and found it effective and financially warranted⁴. The NHS Centre for Reviews and Dissemination⁵ recently carried out a full systematic review of CR and came to the following conclusions;

• CR brings a range of benefits and this may include reduced mortality,

• it is effective in reducing morbidity, symptom report and improving quality of life,

• it is most effective when it combines exercise with psychological and educational interventions,

• exercise programmes alone do not reduce risk factors or mortality or improve quality of life.

The British Cardiac Society have endorsed the value of CR and listed those groups of patients who may benefit, these include; post MI and surgery patients and patients with heart failure and angina⁶.

CR for angina: the evidence

In describing angina, Heberden also noted the case of a patient who had set himself to sawing wood each day and achieved a complete abolition of angina⁷. This anecdotal observation has since been corroborated as an ancillary finding in some, but not all, studies of CR for post MI patients and more convincingly in controlled trials of CR programmes specifically designed for angina⁸. For example, Schuler used a low fat diet in combination with 12 months attendance at a high intensity exercise programme and reported a 54% reduction in exercise-stress-induced myocardial ischaemia (thallium-102 scintigaphy), accompanied by a 21% increase in maximum work capacity⁹. In a crossover trial comparing drug treatment with six months of a high-intensity exercise programme (the Canadian Air Force fighter pilots regime) in middle-aged men, Iain Todd demonstrated that exercise was as effective beta blockade as an anti-anginal agent¹⁰. Three studies of exercise in combination with a low fat diet have also shown regression, or relative halting, of atheroschlerosis¹¹. It is believed that exercise brings about these improvements through a reduction in effort-induced myocardial ischaemia caused by a decreased myocardial oxygen demand and increased work capacity¹². Certainly training can:

• increase exercise tolerance

• prolong the time to ischaemic ECG changes

• possibly promote the growth of collateral vessel formation within the myocardium.

As in other areas of cardiac rehabilitation, combining exercise training with psycho-social treatments and secondary prevention leads to significantly better results. Rehabilitation programmes that have included substantial amounts of attention to psychological factors have been particularly successful in reducing angina. In the Lifestyle Trial patients, who were removed from all medication, reported a 90% reduction in angina and 82% showed regression at one year¹³. In a crossover trial, of a specially designed 8 week Angina Management Programme, patients reported a 70% reduction in episodes of angina and a 72% improvement in QUOL at one year¹⁴. Many of these patients had already had CABG or angioplasty with poor results, or were unsuitable for these procedures. Psychological treatments may be particularly relevant in cases of refractory angina and are discussed in more detail in the accompanying chapter.

Who can take part?

Patients with unstable angina may be required to delay a formal exercise programme until further investigations or revascularisation has been undertaken¹⁵. However, once the angina is stable, participation in an exercise programme is likely to be beneficial. Patients with heart failure and arrhythmias may also benefit, although in the latter case any home exercise should obviously be carefully monitored. In our own work we have chosen to exclude (from the exercise component only) patients who experience a severe drop in BP on exercise testing. In summary, the greater cardiac reserve produced by exercise rehabilitation indicates that this type of programme is safe and effective for almost all patients with chronic stable angina.

What should a CR programme for angina consist of?

The ideal programme has not been established but it is important to realise that CR is a multidisciplinary activity requiring attention to both medical and psycho-social factors, a programme of exercise on its own does not accord with the national guidelines for cardiac rehabilitation¹⁶. A comprehensive cardiac rehabilitation programme should aim to include:

• secondary prevention through both medication and lifestyle change. As well as reducing cardiac risk, weight loss, improved control of blood pressure and optimal use of medication may all reduce angina.

• education and advice, not only about risk factors and medication but also to reduce many of the exaggerated fears that patients have, these are dealt with at greater length in the companion paper.

• screening and appropriate treatment for anxiety and depression , both are intimately linked to self report of symptoms. General `counselling' has not been shown to help in these conditions.

• many patient report that most of their angina occurs when they are stressed or excited relaxation training and stress management has been shown to help such patients.

• an exercise programme and home practice, ideally patients should exercise at least 5 times per week although sessions need not last more than 20 minutes⁷. Our experience and a comparison of results from the previous trials suggests that the average 6-12 weeks of exercise common in most CR programmes in the UK is not sufficient to reduce angina⁸ possibly because the beneficial cardiac adaptations take longer than this to develop.

• patients may also have social and vocational needs that require attention from specialist services.

Ideally the services of the following disciplines should be available, clinical psychologist, doctor, dietician, nurse, occupational therapist, physiotherapist, pharmacist and social worker. The national guidelines suggest that the patients' needs should be assessed using validated measures and that they should receive the appropriate treatment from a `menu' rather than all patients having to attend for every part of a regimented programme¹⁶.

Conclusions

There is good evidence that CR is a useful adjunctive treatment for angina that can improve exercise tolerance, reduce the frequency of anginal episodes and provide worthwhile secondary prevention. If patients can be persuaded to make radical lifestyle changes it may also be possible to prevent the further development of CAD.

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Authors:

David A Brodie (University of Liverpool) and Robert J P Lewin (University of York)

References

1. World Health Organisation. Needs and action priorities in cardiac rehabilitation and secondary prevention in patients with coronary heart disease. Geneva: WHO Regional Office for Europe, 1993.

2. O'Connor GT, Collins R, Buring JE et al (1989). Rehabilitation with exercise after myocardial infarction. Circulation; 82: 234-44.

3. Oldridge NB, Guyatt, GH, Fischer ME, Rimm AA (1988). Cardiac rehabilitation after myocardial infarction: combined experience of randomized clinical trials. JAMA; 260: 945-50.

4. Wenger NK, Froelicher ES, Smith LK et al (1995). Cardiac Rehabilitation as Secondary Prevention. Agency for Health Care Policy and Research and National Heart, Lung, and Blood Institute, Rockville, Maryland 1995.

5. NHS Centre for Reviews and Dissemination, University of New York. Cardiac Rehabilitation. Effective Health Care Bulletin 1988; 4: 1-2.

6. Horgan, J., Bethell, H., Carson, P., Davidson, C., Julian, D., Mayou, R.A., Nagle, R., (1992) British Cardiac Society: Working party report on cardiac rehabilitation. British Heart Journal, 67, 412-8.

7. Heberden, W. Some account of a disorder of the breast. Med. Transactions 1772; 2: 59-67.

8. Lewin, B. The psychological and behavioural management of angina. Journal of Psychosomatic Research 1997; 43: 5: 453-462.

9. Schuler, G., Schlierf, G., Wirth, A., Thumm, M., Roth, H., Mehmel, H.C. and Kubler, W. Low fat diet and regular, supervised physical exercise in patients with symptomatic coronary artery disease: Reduction of stress-induced myocardial ischaemia. Circulation 1988; 77: 172-181.

10. Todd, I.C. and Ballantyne, D. Antianginal effeicacy of exercise training: A comparison with b blockade. British Heart Journal 1990: 4: 14-19.

11. Regression of Atherosclerosis: A review, 1997, Schell WD, Myers JN, Progress in Cardiovasculr Disease, xxxix, 483-496.

12. National Institute of Health. NIH Consensus Statement, Physical Activity and Cardiovascular Health. 1995; 13(3): pp33.

13. Ornish, D., Brown, S.E., Scherwitz, L.W., Billings, J.H., Armstrong, W.T., Ports, T.A., McLanahan, S.M., Kirkeeide, R.L., Brand, R.J. and Gould, K.L. Can lifestyle changes reverse coronary heart disease? Lancet 1990; 336: 129-133.

14. Lewin, B., Cay, E.L., Todd, I., Soryal, I., Goodfield, N., Bloomfield, P. and Elton, R. The angina management programme: A rehabilitation treatment. British Journal of Cardiology 1995; September: 221-226.

15. British Association for Cardiac Rehabilitation. Guidelines for Cardiac Rehabilitation. Eds. Coats, A., McGee, H., Stokes, H. and Thompson, D. Oxford Blackwell Science, 1995.

16. Thompson, D.R., Bowman, G.S., Kitson, A.L., De Bono, D. and Hopkins, A. Cardiac rehabilitation in the UK: Guidelines and audit standards. Heart 1996; 75: 89-93.

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