The randomized controlled trials that documented favorable weight reduction in intervention versus control patients identified this outcome after relatively long followups of 4 years, 17 2 years, 14 and 1 year.41 Two of the seven nonrandomized controlled studies were multifactorial; both showed no difference between groups regarding changes in body weight.20,167 The remaining five nonrandomized controlled trials involved exercise training as the sole intervention. Two reported a favorable effect on body weight, body mass index, and lean body mass for exercise versus control patients.79,174 The other three reported no significant differences between groups in body weight, body mass index, or skin-fold measurements.23,72,172 Eight of the 16 observational studies of exercise-based rehabilitation reported significant reduction in measures of body weight or body mass index.30,177,179,185,186,196,198,223 Eight of the observational studies reported no significant change.31,79,168,173,182,189,200,202 Conclusions Rehabilitative exercise training, when a component of multifactorial intervention, appears to have a beneficial effect in improving body weight or other measures of excess body mass or percentage of body fat. Exercise training as a sole intervention has no consistent effect. No exercise-training study specifically targeted overweight coronary patients, and delineation of what constituted being "overweight" varied among studies. There is a clear need to scientifically evaluate the role of multifactorial cardiac rehabilitation in effecting desired weight change in overweight patients with coronary disease. Also, it is recognized that sustained weight loss has been a difficult goal to achieve in a number of different clinical and population studies. Approximately half of the studies dealt only with male patients, and studies that included women had a small proportion of women patients (12-20 percent). The sole study that reported outcomes by gender showed no significant difference between men and women in improvement in the percentage of body fat.182 No study presented outcomes based on the degree of patients' overweight or obesity at baseline. These studies principally involved patients who were younger than 65 years of age, with the mean age predominately in the 50s. One nonrandomized controlled trial reported favorable changes in body mass index in patients both younger and older than 65 years of age.30 Blood Pressure RECOMMENDATION Rehabilitative exercise training as a sole intervention has no demonstrable effect in lowering blood pressure levels. Multifactorial cardiac rehabilitation, including exercise training, has an inconsistent effect in lowering blood pressure levels; major confounding variables include the use of antihypertensive medication and medication changes. Scientific Evidence (Strength of Evidence = B) The scientific data that address the effect of exercise training, with and without other cardiac rehabilitation services, on blood pressure levels include 18 studies: 9 randomized controlled trials, 6 nonrandomized controlled studies, and 3 observational reports. Three of the nine randomized controlled trials involved patients after myocardial infarction and reported a favorable effect of rehabilitative exercise training versus control status on mean blood pressure levels, with an average blood pressure reduction of 7 mmHg systolic and 4 mmHg diastolic; 14.17.49 all three studies were multifactorial. Five randomized controlled trials reported no significant difference in blood pressure levels between exercise and control patients; three were multifactorial,41,160,228 and two involved only exercise training.16,42 One multifactorial study reported significant lowering of systolic blood pressure levels in intervention patients compared with control patients.39 Five of the six nonrandomized controlled studies reported a statistically significant greater reduction in blood pressure in rehabilitation patients versus control patients; these included four multifactorial studies28,162,167,169 and one exercise-only trial.79 One multifactorial study reported no difference.175 When sufficient data were available, average reductions in systolic and diastolic blood pressures between intervention and control groups were 13 and 10 mmHg, respectively. 14,162 One observational study reported improved home-monitored blood pressure control following rehabilitation,223 and two did not.31,173 Detailed information regarding potential confounding variables such as concomitant changes in body weight, percentage of body fat, habitual physical activity, dietary habits, and particularly the percentage of patients taking antihypertensive medications (as well as adherence to antihypertensive medications) was often lacking, thereby limiting the value of the results. Patients with elevated baseline blood pressure levels generally showed the greatest reductions in blood pressure with exercise training. Many coronary patients were normotensive or mildly hypertensive at baseline. Conclusions Review of the scientific evidence suggests that exercise-based cardiac rehabilitation has only modest effects in reducing blood pressure levels. The generalizability of these data is limited by the small numbers of women who were enrolled in these studies. Of major importance is that no study was specifically designed to address hypertension control in patients with elevated blood pressures participating in exercise-based cardiac rehabilitation. The confounding effects on blood pressure change of weight reduction, dietary habits, and antihypertensive medications was not addressed in any of the studies. It is unlikely that hypertensive patients with coronary disease would be provided solely exercise training without other appropriate therapies such as weight reduction, sodium restriction, moderation or abstinence from alcohol, or pharmacologic therapy, although these components may have been directed by the patient's treating physician. The panel supports the recommendations of The Fifth Report of the Joint National Committee on Detection, Evaluation and Treatment of High Blood Pressure (JNC V), advising physical activity as a nonpharmacologic approach to the control of elevated blood pressure.238 Most exercise-based cardiac rehabilitation studies that reported blood pressure changes were conducted in relatively young patients, generally younger than 65 years of age. Only two studies included elderly patients.31.39 The effect of exercise rehabilitation on elderly patients with elevated blood pressures has not been well defined. Furthermore, the more intensive use of pharmacologic therapies to control elevated blood pressure levels in contemporary cardiovascular care may render the information from older trials less meaningful. Psychological Well-Being RECOMMENDATION Cardiac rehabilitation exercise training-with and without other cardiac rehabilitation services-generally results in improvement in measures of psychological status and functioning. Exercise training as a sole intervention does not consistently result in improvement in measures of anxiety and depression. Exercise training is recommended to enhance measures of psychological functioning, particularly as a component of multifactorial cardiac rehabilitation. Scientific Evidence (Strength of Evidence = B) Nineteen scientific studies reported a variety of measures of psychological status or functioning before and after exercise-based cardiac rehabilitation. Nine were randomized controlled trials, eight were nonrandomized controlled studies, and two were observational studies. The randomized and nonrandomized controlled trials that reported measures of psychological outcomes are presented in Tables 5 and 6. Three of the nine randomized controlled trials involved only exercise training. Two of these three reported statistically significant improvement in various measures of psychological functioning favoring rehabilitation patients versus control patients.69,154 The other exercise-only trial reported no statistically significant difference between groups.219 One randomized controlled trial compared exercise versus exercise plus education/counseling versus control status in patients after myocardial infarction and evaluated changes in the Sickness Impact Profile at 3- and 6-month followups. 103 The measures of dysfunctional behavior showed significant improvement in the exercise plus education/counseling group versus exercise-only or control groups at both 3 and 6 months. The exercise plus education/counseling group showed significant improvement compared with control patients in measures of social interaction at 3 and 6 months. Four additional randomized controlled trials involved multifactorial interventions. Three showed significant improvement in psychological variables in the rehabilitation patients,151,156,239 and one showed significant improvement in measures of quality of life.156 One multifactorial randomized controlled trial reported no difference between groups. An additional randomized controlled trial compared high-intensity with light-intensity exercise training in men after myocardial infarction and reported no significant differences between groups in any measure of psychological functioning or quality of life at the 4- and 12-month followups. Significantly greater mean improvement in the score of occupational adjustment occurred in the high-intensity group, but there was no significant difference between groups at the 12-month followup.159 Five of the eight nonrandomized controlled studies reported statistically significant beneficial outcomes favoring intervention patients versus control patients. Three of these five involved exercise training as the sole intervention,72,167,173 and two studies were multifactorial.240,241 (One report described two separate studies, one observational and one nonrandomized controlled.) The three other nonrandomized studies did not report any tests of statistical significance for their results.78,165,166 Two observational studies reported improvement in psychological measures following rehabilitation,240,242 In summary, 13 of 17 randomized and nonrandomized controlled studies documented statistically significant improvement in various measures of psychological status favoring rehabilitation versus control patients, including 7 of 9 exercise-only studies and 4 of 6 multifactorial studies. No study documented worsening of measures of psychological status comparing rehabilitation with control patients. Conclusions Cardiac rehabilitation exercise training, either alone or as a component of multifactorial rehabilitation, often results in improvement in various measures of psychological status and functioning. This evidence from the scientific literature is consistent with the widespread belief among cardiac rehabilitation professionals that cardiac rehabilitation exercise training improves the sense of well-being among participants. The evidence particularly supports improvement among individuals with high levels of distress at the time of entry into the study. The instruments used to measure psychological outcomes differed widely and are those often designed to measure abnormal responses and changes in patients with psychological or psychiatric illness; even with use of these instruments, improvement in psychological status was documented in patients not specifically targeted because of psychological illness. Patients tended to perceive themselves as improving in a number of psychosocial domains, although these perceptions may not have been objectively documented. More sensitive tests may have to be developed to better ascertain changes in cardiac patients without specific psychiatric illness, and those data are very limited for elderly patients. |