Background: Exercise is currently recommended for patients after myocardial infarction; however, the effects of regular exercise on the remodeling process remain to be defined. The aim of this multicenter, randomized study was to investigate whether a long-term physical training program influences left ventricular size and function in postinfarction patients with systolic dysfunction.
Methods and results: Consecutive patients with <40% ejection fraction after a first Q-wave myocardial infarction were randomly assigned to a 6-month exercise training program (n=39) or control group (n=38). After 6 months, a significant increase in work capacity was observed only in the training group (from 4.462+/-1.095 to 5.752+/-1.749 kilopond-meters [Kp-m], P<.01), not in the control group (from 4.375+/-1.143 to 4.388+/-1.199 Kp-m), whereas left ventricular volumes had increased in the control group (end-diastolic volume, from 94+/-26 to 99+/-27 mL/m2, P<.01; end-systolic volume, from 62+/-20 to 67+/-23 mL/m2, P<.01) but not in the training group (end-diastolic volume, from 93+/-28 to 92+/-28 mL/m2, P=NS; end-systolic volume, from 61+/-22 to 57+/-23 mL/m2, P=NS). Conversely, ejection fraction had improved in the training group (from 34+/-5% to 38+/-8%, P<.01) but not in the control group (from 34+/-5% to 33+/-7%, P=NS).
Conclusions: In postinfarction patients with systolic dysfunction, long-term exercise training may attenuate the unfavorable remodeling response and even improve ventricular function over time.