Attenuation of Unfavorable Remodeling by Exercise Training in Postinfarction Patients With Left Ventricular Dysfunction

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/m 2 , P <.01; end-systolic volume, from 62±20 to 67±23 mL/m 2 , P <.01) but not in the training group (end-diastolic volume, from 93±28 to 92±28 mL/m 2 , P =NS; end-systolic volume, from 61±22 to 57±23 mL/m 2 , 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.