Predictors of left ventricular remodeling in patients with acute myocardial infarction participating in cardiac rehabilitation.

BACKGROUND This study was designed to determine the factors influencing the development of left ventricular (LV) remodeling in patients participating in a comprehensive cardiac rehabilitation (CR) program after acute myocardial infarction (AMI), with special reference to exercise intensity and frequency. METHODS AND RESULTS A total of 72 patients with AMI participated in CR consisting of exercise training of moderate intensity (heart rate reserve 40-60%) and education for 12 weeks. Plasma concentration of brain natriuretic peptide (BNP) was measured at the beginning and the end of CR. Echocardiography was performed before and 1 year after CR. An increase in LV end-diastolic dimension (delta-LVDd) from baseline was used as an index of remodeling. Delta-LVDd was significantly greater in patients with an anterior AMI than with other infarct locations (p<0.05) and correlated significantly with baseline BNP concentration (p<0.05). Delta-LVDd >5 mm occurred exclusively in patients with baseline BNP >150 pg/ml. Variables representing the intensity and frequency of exercise training did not correlate with delta-LVDd. CONCLUSIONS In patients with AMI participating in CR, those having both anterior infarction and baseline BNP concentration >150 pg/ml are at high risk for subsequent LV remodeling, whereas neither exercise intensity nor participation frequency in CR appears to be associated with LV remodeling.