training compared with aerobic training,70 and no differences in measures of left ventricular performance after 6 months of exercise training compared with control status in male patients following myocardial infarction with baseline left ventricular ejection fractions of less than 40 percent. 18 An additional randomized controlled trial reported no differences in ST-segment depression or ventricular arrhythmia during home exercise training compared with no-exercise controls.12 The final two randomized controlled trials reported no significant differences in “complications” in intervention patients compared with control patients.36,37 Conclusions On the basis of the randomized controlled trials reported in the scientific literature, there is no evidence for reduction in cardiac morbidity, most specifically nonfatal reinfarction, as a result of exercise rehabilitation. No study documented an increase in morbidity comparing rehabilitation patients with control patients in 4,578 patients included in the controlled trials (randomized and nonrandomized) reviewed. No study reported reinfarction or other morbidity rates by gender or by age. Only one randomized controlled trial included patients with varied presentations of coronary disease:39 all other randomized controlled trials were of patients following myocardial infarction. The larger of the two surveys of adverse experiences during rehabilitative exercise training in 142 U.S. cardiac rehabilitation programs (1980-84) reported a very low rate of nonfatal reinfarction of 1/294,000 patient-hours.65 It should be emphasized that these 1980–84 survey data may not be applicable to contemporary treatment of coronary patients. Specifically, the widespread use of risk stratification procedures following myocardial infarction, the more aggressive management techniques including thrombolytic therapy and myocardial revascularization, as well as current pharmacologic therapies for postinfarction patients (e.g., beta blockers, ACE inhibitors) may further reduce reinfarction and morbidity in coronary patients. The current low nonfatal reinfarction rates may not be amenable to further reduction by exercise training as a sole intervention. Morbidity outcome data must be obtained for older coronary patients, female patients, and higher risk patients participating in exercise rehabilitation. Appropriately designed and conducted exercise-based cardiac rehabilitation can safely be undertaken in appropriately selected patients undergoing individualized initial assessment and surveillance. Mortality and Safety Issues RECOMMENDATION On the basis of the meta-analytical data, total and cardiovascular mortality are reduced in patients following myocardial infarction who participate in cardiac rehabilitation exercise training, especially as a component of multifactorial rehabilitation. Scientific Evidence (Strength of Evidence = B) The scientific evidence pertaining to the relationship of cardiac rehabilitation exercise training to mortality includes 31 scientific reports. Seventeen reports were from 16 randomized controlled trials (1 trial reported 3- and 10year followup data), eight were nonrandomized controlled studies, and six were observational reports. In addition, two survey questionnaire reports provided information regarding mortality rates. Four of the 16 randomized controlled trials reported a statistically significant decrease in mortality favoring rehabilitation versus control patients. Three-year coronary mortality and sudden death rates were significantly lower (p < .02) in patients following myocardial infarction with multifactorial cardiac rehabilitation starting 2 weeks after hospital discharge.14 This beneficial outcome persisted at the 10-year followup.49 The largest center from a multicenter European trial of exercise-only rehabilitation in male patients following myocardial infarction reported significant reduction in total mortality favoring rehabilitation versus control patients (p < .01).51 In a randomized controlled trial that demonstrated mortality reduction associated with exercise training as the sole intervention, benefit was limited to patients with inferior wall myocardial infarction (p < .01).10 The final randomized controlled trial that reported favorable reduction in total mortality compared myocardial infarction patients who received exercise rehabilitation with patients who received only counseling and usual care. Total mortality was significantly reduced (p = .03) in exercising patients compared with the combined counseling and usual-care patient groups. 52 The 10 additional randomized controlled trials, which involved 4,747 patients, reported no difference in mortality between rehabilitation and control patients. 16,17,36,39,50,153,161,249,259,260 Two additional randomized controlled trials reported no mortality difference comparing high- and low-intensity exercise training groups. 15.159 These trials are summarized in Table 8. No randomized controlled trial reported excess mortality in rehabilitation groups compared with control patient groups. Eight nonrandomized controlled trials reported mortality outcomes. Two of these trials reported a statistically significant reduction in mortality in rehabilitation versus control patients.40.252 Three multifactorial nonrandomized controlled trials showed no mortality difference between rehabilitation and control groups. 20,169,175 One study established significant mortality reduction only after 10 years of followup,40 compared with the 5-year followup data.169 No difference in mortality was noted in three other nonrandomized controlled trials in which exercise training was the sole intervention.21,83,261 The six observational studies that reported mortality data had no control groups for comparison.38,81,183,196,229,248 Two large survey reports establish low rates of cardiac death during rehabilitation exercise training: 1/116,400 patient-hours in the early years of rehabilitation (1960–77)59 and 1/784,000 patient-hours in more recent years (1980–84),65 Caution regarding these rates Table 8. (continued) Reference, Country Kallio, Hamalainen, Shaw Lamm, Patients Sample size: 325 (187 Gender: 150 men Intervention, Followup Outcome Intervention: Age: <65 years, mean psychosocial advice. Coronary mortality: Sudden death: Total mortality: 21.8% intervention 29.9% control (p <.10) Total mortality: CV mortality: 11/17 centers reported mortality favoring intervention vs. control (3 statistically significant, p < .05) Largest center (405 patients). Total mortality: 5.7% intervention, 15.6% control (p < .01). |