Influence of treatment delay on long-term left ventricular function in patients with acute myocardial infarction successfully treated with primary angioplasty

Background Myocardial salvage has been shown to be dependent on the time el apsed from the onset of acute myocardial infarction (AMI) to reperfusion. T he aim of this study was to evaluate the importance of time to reperfusion For left ventricular function recovery after primary angioplasty (percutane ous transluminal coronary angioplasty [PTCA]) for AMI. Methods Ninety-five patients undergoing long-term successful PTCA for AMI w ere studied. Echocardiography was per formed before and 3, 7, 30, 90, and 1 80 days after PTCA. End-diastolic volume index (EDVI) and end-systolic volu me index (ESVI), ejection fraction, and left ventricular wall motion score index (WMSI) were evaluated. Results Patients were divided into group A, 23 patients reperfused within 2 hours; group B, 32 patients reperfused between 2 and 4 hours; group C, 22 patients reperfused between 4 and 6 hours; and group D, 18 patients reperfu sed between 6 and 12 hours. Both EDVI and ESVI were reduced in groups A and B at 90 days. Groups C and D did not show any changes of EDVI and ESVI at any stage throughout the study. Ejection fraction improved only in groups A and B at 30, 90, and 180 days. At study entry, WMSI was similar in all gro ups. After 7 days, in group A and in group B, WMSI was improved, no changes were observed in group C, and a mild deterioration was observed in group D at 3 and 7 days. Subsequent evaluations showed progressive improvement of WMSI in all groups. Conclusions Myocardial salvage is achieved only in patients revascularized within 4 hours from AMI onset. However, revascularization after 6 hours may be worthwhile by preventing ventricular remodeling.