TISSUE-TYPE PLASMINOGEN-ACTIVATOR THERAPY VERSUS PRIMARY CORONARY ANGIOPLASTY - IMPACT ON MYOCARDIAL TISSUE PERFUSION AND REGIONAL FUNCTION1 MONTH AFTER UNCOMPLICATED MYOCARDIAL-INFARCTION

Objectives. This study sought to compare the impact of primary coronar y angioplasty and thrombolytic therapy for acute myocardial infarction (AMI) on 1-month infarct size and microvascular perfusion. Background . The effect of the reperfusion strategies of primary coronary angiopl asty and thrombolytic therapy on microvascular integrity still remains to be determined. Methods. Sixty two consecutive patients with a firs t AMI, undergoing intravenous tissue-type plasminogen activator (t-PA) therapy (32 patients, Group I) or primary angioplasty (30 patients, G roup II), were studied. Only patients with 1-month Thrombolysis in Myo cardial Infarction (TIMI) flow grade 2 or 3 were selected for the stud y, Patients in whom primary angioplasty was unsuccessful or those with clinical evidence of failed reperfusion were excluded. Microvascular perfusion was assessed at 1 month by intracoronary injection of sonica ted microbubbles. Contrast score index (CSI) and wall motion score ind ex (WMSI) were derived using qualitative methods. Results. At baseline there were no significant differences between groups for age, risk fa ctors, time to hospital presentation, Killip class on admission, preva lence of multivessel disease or anterior infarct site, infarct area ex tension before reperfusion, peak creatine kinase levels and postinfarc tion treatment. Conversely, significant differences between groups wer e found at follow-up for percent residual infarct related-artery (IRA) stenosis (70 +/- 12 vs 36 +/- 14 [mean +/- SD], p = 0.0001), CSI (1.0 2 +/- 0.4 vs. 1.49 +/- 0.5, p = 0.0003) and WMSI (1.67 +/- 0.3 vs. 1.4 5 +/- 0.3, p = 0.015). In particular, in the subset of patients with T IMI grade 3 flow, a perfusion defect occurred in one or more segments subtended by the IRA in 72% of Group I versus 31% of Group II patients (p < 0.00001) and in 27% of Group I versus 8% of Group II segments (p < 0.00001), Conclusions. The present study shows, in a highly selecte d cohort with successful IRA recanalization, that primary angioplasty is more effective than thrombolysis in preserving microvascular flow a nd preventing extension of myocardial damage at 1-month after AMI. (C) 1998 by the American College of Cardiology.