Does cardiac rehabilitation increase long-term survival after myocardial infarction?

Cardiac rehabilitation and 5-year mortality after acute coronary syndromes: The 2005 French FAST-MI study

BACKGROUND

Clinical studies have shown a beneficial effect of cardiac rehabilitation (CR) on mortality.

OBJECTIVE

To study the effect of CR prescription at discharge on 5-year mortality in patients with acute myocardial infarction (AMI).

METHODS

Participants, from the 2005 French FAST-MI hospital registry, were 2894 survivors at discharge, divided according to AMI type: ST-segment elevation myocardial infarction (STEMI; n=1523) and non-STEMI (NSTEMI; n=1371). The effect of CR prescription on mortality was analysed using a Cox proportional hazards model.

RESULTS

At discharge, 22.1% of patients had a CR prescription. Patients referred to CR were younger (62.4 vs. 67.5years), were more frequently men and more had presented with STEMI (67.8% vs. 48.3%) than non-referred patients. Ninety-four (14.7%) deaths occurred among patients referred to CR and 585 (25.9%) among non-referred patients (P<0.001). After multivariable adjustment, the association between CR and mortality remained significant (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.60-0.96). Analyses stratified by sex, age (<60 vs.≥60years) and AMI type showed that the inverse association was stronger in men (HR 0.64, 95% CI 0.48-0.87) than in women (HR 0.95, 95% CI 0.64-1.39), in younger (HR 0.34, 95% CI 0.15-0.77) than in older patients (HR 0.84, 95% CI 0.65-1.07) and in NSTEMI (HR 0.63, 95% CI 0.46-0.88) than in STEMI (HR 0.99, 95% CI 0.69-1.40).

CONCLUSION

After hospitalization for AMI, referral to CR remains a significant predictor of improved patient survival; some subgroups seem to gain greater benefit.

Process and Outcome in Cardiac Rehabilitation: An Examination of Cross-Lagged Effects

Cardiac rehabilitation patients improve cardiorespiratory fitness and quality of life, yet therapeutic processes that produce these changes remain unknown. A cross-lagged panel design was used to determine whether early-treatment enhancement of self-efficacy regarding abilities to change diet and exercise habits and the quality of the patient-staff working alliance predicted late-treatment changes in a wide range of outcomes, but not vice versa. Eighty cardiac patients participating in a 12-week program completed measures at early, mid- and late treatment. Early-treatment changes in exercise self-efficacy predicted late-treatment changes in activity level, depression, and working alliance, but not vice versa. Diet self-efficacy changes correlated with concurrent changes in fat intake and body weight. Early-treatment changes in cardiorespiratory fitness and activity level predicted late-treatment changes in working alliance, but not vice versa. Findings suggest that increased exercise self-efficacy represents an important therapeutic mechanism by which rehabilitation gains are realized. ((c) 2004 APA, all rights reserved)

Effect of exercise intensity and frequency on lipid levels in men with coronary heart disease: Training Level Comparison Trial

The objective of the Training Level Comparison Trial was to determine whether a more intense exercise program versus a less intensive program has additional favorable effects on blood lipids in men with coronary heart disease (CHD) over a 12-month period. The study-a randomized, controlled trial conducted at 2 clinical centers-enrolled 185 patients with documented CHD. A simple randomization procedure led to unequal numbers of patients in the 2 interventions: 82 in the low-intensity and 103 in the high-intensity group. Target heart rate during exercise corresponded to 50% of maximum oxygen uptake (VO(2 max)) +/- 5 beats/min in the low-intensity group and 85% +/- 5 beats/min in the high-intensity group. The intensity of exercise made little difference on lipid improvements. However, the attendance rates for the 6- and 12-month periods (percentage of total exercise sessions attended) were significantly related to increased high-density lipoprotein (HDL) cholesterol (r(s) [Spearman rank correlation coefficient 0.20 to 0.26, p <0.05]), and decreases in the ratios of low-density lipoprotein (LDL)-to-HDL cholesterol (LDL:HDL, r(s) = -0.24 to -0.28, p < 0.01) and total-to-HDL cholesterol (total:HDL, r(s) = -0.25 to -0.29, p < 0.01) at 6 and 12 months. The relation of the attendance rate to LDL:HDL and total:HDL ratios remained significant in repeated-measures regression analysis. Exercise frequency may be more important than intensity in improving HDL cholesterol and LDL:HDL and total:HDL ratios in men with CHD.

Cardiac rehabilitation: structure, effectiveness and the future

Despite advances in the investigation and treatment of angina and myocardial infarction, and increased knowledge of the factors associated with the development and progression of ischaemic heart disease, it remains the leading cause of death and morbidity in the majority of industrialized countries. Cardiac rehabilitation provides a means of modifying lifestyle and other risk factors in patients presenting with established, symptomatic coronary artery disease, thereby reducing the risk of further cardiac events. It has also been proven to be cost-efficient.

Evaluation of a home-based rehabilitation programme for patients recovering from acute myocardial infarction

There is substantial evidence of the importance of rehabilitation for patients recovering from acute myocardial infarction in reducing mortality, morbidity, and psychological distress. The aim of this study was to compare a recently established home-based coronary rehabilitation programme in a coronary care unit (CCU) with the provision of a selection of information leaflets commonly provided for patients after their myocardial infarction. A comparative study was carried out between two randomly allocated groups of patients receiving either the Heart Manual rehabilitation programme (n = 17) or general advice and information booklets (n = 17), with follow-up at 1, 3 and 6 weeks after discharge for both groups. Questionnaire measurements included anxiety and depression (HAD score), general practitioner (GP) visits, and patients' perception of their confidence of recovery and progress. The findings show that patients receiving the Heart Manual had significantly higher scores in their confidence of recovery and perception of their progress than the group receiving booklets. The Heart Manual group showed improved levels of anxiety with unchanged scores in depression, while patients receiving the booklets experienced increased depression with little change in their anxiety levels. These results help to provide guidance for health care professionals on a form of rehabilitation which is effective for patients and their families in hospital and within the community.

Design of the training levels comparison trial

The Training Levels Comparison (TLC) trial was a grant-supported, multicenter, randomized, controlled clinical trial designed to determine whether cardiac rehabilitation patients would benefit from supervised exercise for a prolonged period (2 years) and whether subjecting patients to a more vigorous exercise program than currently recommended would provide additional cardiac benefit. If high-intensity exercise does not enhance the cardiac benefit, then physical activity should be limited to low-intensity levels that are safer, easier to implement and more adaptable to a greater number of patients. Patients were randomly assigned to either a low-intensity or high-intensity training program. All patients were to attend three 1-hour supervised exercise sessions per week for a period of 2 years. Attendance at exercise sessions and adherence to assigned treatments were monitored throughout the study. Patients were evaluated for outcome measures at 3, 6, 12, and 24 months. This paper reports the study design and methodology for the TLC trial, and should be useful in providing methodologies to facilitate comparison of data from other studies with different levels of exercise as an intervention.

Economic evaluation of cardiac rehabilitation soon after acute myocardial infarction

Although there are extensive clinical evaluations of cardiac rehabilitation after acute myocardial infarction (AMI), no full economic evaluation is available. Patients with AMI and mild to moderate anxiety or depression, or both, while still in hospital were randomized to either an 8-week rehabilitation intervention (n = 99) or usual care (n = 102). Comprehensive costs and health-related quality of life, measured with the time trade-off preference score, were obtained in a 12-month trial, and together with survival data derived from published meta-analyses, cost-utility and cost-effectiveness of early cardiac rehabilitation were estimated. The best estimate of the incremental net direct 12-month costs for patients randomized to rehabilitation was $480 (United States, 1991)/patient. During 1-year follow-up, rehabilitation patients had fewer "other rehabilitation visits" (p < 0.0001) and gained 0.052 quality-adjusted life-year more than did the group with usual care. The cost-utility ratio was $9,200/quality-adjusted life-year gained with cardiac rehabilitation during the year of follow-up. This economic evaluation of cardiac rehabilitation does not consider the important distinctions between affordability and worth of alternative health-care services. The data provide evidence that brief cardiac rehabilitation initiated soon after AMI for patients with mild to moderate anxiety or depression, or both, is an efficient use of health-care resources and may be economically justified.

Exercise training for patients with coronary artery disease. Cardiac rehabilitation revisited

Medically prescribed and supervised physical activity forms the keystone for cardiac rehabilitation. A patient's potential and limitations for successful participation in an active restoration programme are determined by the degree of symptomatic recovery and physiological adaptations to a standardised, multistage exercise test. Confirmation of the effects of physical activity intervention is measured by the performance of the same exercise test under near identical conditions at periodic intervals. The prescribed physical activity regimen is usually performed minimally 3 times per week in sessions which last from 30 to 60 minutes. The object is to utilise from 100 to 200 kcal per exercise session. The demonstrated benefits of regular physical activity include reduction of the systolic blood pressure and heart rate at supine rest and while performing submaximal work, an increased level of physical work capacity, reduction in the myocardial oxygen cost at rest and during performance of submaximal exercise, reduction in percentage body fat with a concomitant increase in muscle mass, and reduction in plasma triglycerides. Regular physical activity, in and of itself, does not effect a reduction in plasma cholesterol or an increase in high density lipoprotein cholesterol, nor does it affect such lifestyle habits as cigarette smoking and alcohol consumption. While contraindications to performing medically prescribed and supervised physical activity are usually restricted to the physically incapacitated patient, failure to achieve an exercise threshold for systolic blood pressure of 140mm Hg or higher is probably a contraindication. This conclusion is based on findings which indicate that treated and control patients with this physiological limitation experience the same mortality rates over 3 years. Regularly performed physical activity by coronary artery diseased patients is associated with reductions in mortality from all cardiovascular causes except sudden death. This intervention does not effect morbidity. Although the scientific evidence warrants the prudent use of physical activity for coronary artery disease patients, the case for its long term benefits remains to be proved.

Effects of self-help post-myocardial-infarction rehabilitation on psychological adjustment and use of health services

A home-based exercise programme has been found to be as useful as a hospital-based one in improving cardiovascular fitness after an acute myocardial infarction. To find out whether a comprehensive home-based programme would reduce psychological distress, 176 patients with an acute myocardial infarction were randomly allocated to a self-help rehabilitation programme based on a heart manual or to receive standard care plus a placebo package of information and informal counselling. Psychological adjustment, as assessed by the Hospital Anxiety and Depression Scale, was better in the rehabilitation group at 1 year. They also had significantly less contact with their general practitioners during the following year and significantly fewer were readmitted to hospital in the first 6 months. The improvement was greatest among patients who were clinically anxious or depressed at discharge from hospital. The cost-effectiveness of the home-based programme has yet to be compared with that of a hospital-based programme, but the findings of this study indicate that it might be worth offering such a package to all patients with acute myocardial infarction.