A 2-month exercise training program increased maximal oxygen uptake by 26% (P<0.05) but had no significant effect on end-diastolic volume (196 vs 180 mL) or ejection fraction compared to control.
RCT (n=25)
randomized
Does a 2-month high-intensity exercise training program improve exercise capacity and affect myocardial remodeling in patients with reduced left ventricular function after myocardial infarction?
A 2-month high-intensity residential cardiac rehabilitation program significantly improves exercise capacity without causing deleterious myocardial remodeling in post-myocardial infarction patients with reduced left ventricular function.
Absolute Event Rate: 196% vs 180%
BACKGROUND: There are conflicting reports on the effects of training on the remodeling process in post-myocardial infarction patients with ventricular damage. METHODS AND RESULTS: Twenty-five patients with reduced ventricular function (mean ejection fraction, 32.3+/-6%) after an anteroseptal or inferolateral myocardial infarction were randomized to an exercise group (n=12) or a control group (n=13). Patients in the exercise group resided in a rehabilitation center for 2 months and underwent a training program consisting of two 1-hour sessions of walking daily, along with four monitored 45-minute sessions of stationary cycling weekly. Before and after the study period, maximal exercise testing and cardiac MRI were performed. Oxygen uptake increased 26% at maximal exercise (19.7+/-3 to 23.9+/-5, P<.05) and 39% at the lactate threshold (P<.01) in the exercise group, whereas control values did not change. No differences were observed within or between groups in MRI measures of end-diastolic (187+/-47 pre versus 196+/-35 mL post in the exercise group and 179+/-52 pre versus 180+/-51 mL post in the control group), end-systolic volume (118+/-41 pre versus 121+/-33 mL post in the exercise group and 119+/-54 pre versus 116+/-56 mL post in the control group), or ejection fraction (38.0+/-9 pre versus 38.2+/-10% post in the exercise group and 37.0+/-10 pre versus 38.3+/-13% post in the control group). Myocardial wall thickness measurements at end diastole and end systole and their difference in 80 myocardial segments determined by MRI yielded no significant interactions between groups. When myocardial wall thickness measurements were classified by infarct or noninfarct areas, no differences were observed between groups over the study period. CONCLUSIONS: A high-intensity, 2-month residential cardiac rehabilitation program resulted in substantial increases in exercise capacity among patients with reduced left ventricular function. In contrast to some recent reports, the training program had no deleterious effects on left ventricular volume, function, or wall thickness regardless of infarct area.
Dubach et al. (1997) conducted an RCT in Reduced left ventricular function after myocardial infarction (n=25). Exercise training program vs. Control group was evaluated on End-diastolic volume (mL). A 2-month exercise training program increased maximal oxygen uptake by 26% (P<0.05) but had no significant effect on end-diastolic volume (196 vs 180 mL) or ejection fraction compared to control.