Reverse left ventricular remodeling: effect of cardiac rehabilitation exercise training in myocardial infarction patients with preserved ejection fraction.

BACKGROUND: In the increasingly prevalent population of postmyocardial infarction (MI) patients with preserved left ventricular (LV) ejection fraction (>45%), the effect of cardiac rehabilitation (CR) exercise training on LV structure and function is unknown. AIM: To examine the reverse LV remodeling effect of CR exercise training in post-MI patients with preserved LV ejection fraction (>45%). DESIGN: Prospective, longitudinal, controlled trial. SETTING: Outpatient CR programme. POPULATION: Fifty six asymptomatic, post-MI patients without residual myocardial ischemia and LV ejection fraction >45%. METHODS: Within 3-6 weeks of MI, and 10 weeks later, echocardiography and cardiopulmonary exercise testing were performed. An exercise training group (N.=36) completed twice weekly gym based cardiovascular exercise (60-80% VO2 peak) and a resistance training programme, whilst a non-exercise group (N.=20) did not. RESULTS: In comparison to the non-exercise group, in which there was no change, 10 weeks of CR exercise training resulted in increased VO2peak and reduced LV end diastolic and systolic volumes (all P<0.05 vs. non-exercise group). CONCLUSIONS: In post-MI patients with preserved LV ejection fraction (>45%), CR exercise training is effective in improving functional capacity and reducing LV volumes. CLINICAL REHABILITATION IMPACT: In this previously unstudied population, the measurement of reverse LV volumetric remodeling may prove useful as an indicator of CR exercise programme efficacy. To maximize the potential clinical benefit from reverse LV remodeling, this patient group, should be actively encouraged to engage in CR exercise training