DETERMINANTS OF LEFT-VENTRICULAR FUNCTION 2 WEEKS AND ONE-YEAR AFTER AN ACUTE MYOCARDIAL-INFARCTION

This study examines possible covariates of left ventricular function t wo weeks and sixteen months after an acute infarction. It was performe d in a group of 312 patients randomized double blindly to recombinant tissue plasminogen activator (rt-PA) (n=156) or placebo treatment and followed thereafter for at least one year. Two weeks after the infarct ion, enzymatic infarct size, infarct-related vessel, and number of dis eased coronary arteries were significant determinants of the infarct-r elated regional wall motion (centerline method) (R(2)=0.25 to 0.60, P= 0.0001). Enzymatic infarct size, regional wall motion of both infarct- related and remote areas, reinfarction, and treatment allocation were significant independent correlates of ejection fraction (R(2)=0.76), e nd-diastolic volume (R(2)=0.20), and end-systolic volume (R(2)=0.69, P < 0.0001). Infarct-related coronary artery and predischarge end-systo lic volume were significant independent covariates of ejection fractio n at rest (R(2)=0.473 after sixteen months. Age, enzymatic infarct siz e, and predischarge end-diastolic volume were independent determinants of the maximal (R(2)=0.49, P < 0.0001) and peak exercise ejection fra ction (R(2)=0.49, P < 0.0001).