Serial evaluation of perfusion defects in patients with a first acute myocardial infarction referred for primary PTCA using intravenous myocardial contrast echocardiography

Aims To investigate whether myocardial contrast echocardiography using Sonazoid(R) could be used for the serial evaluation of the presence and extent of myocardial perfusion defects in patients with a first acute myocardial infarction treated with primary PTCA, and specifically, (1) to evaluate safety and efficacy of myocardial contrast echocardiography to detect TIMI flow grade 0-2, (2) to evaluate the success of reperfusion and (3) to predict left ventricular recovery after 4 weeks follow-up. Methods and Results Fifty-nine patients underwent serial myocardial contrast echocardiography, immediately before primary PTCA (MCE1), 1 h (MCE2) and 12-24 h after PTCA (MCE3). A perfusion defect was observed in 21 of 24 patients (88%) with anterior acute myocardial infarction. All but one had TIMI flow grade 0-2 prior to PTCA. Nine of 31 patients (29%) with inferior acute myocardial infarction showed a perfusion defect and all had TIMI flow grade 0-2 prior to PTCA. Restoration of TIMI flow grade 3 was achieved in 73% of the patients by primary PTCA. A reduction in size of the initial perfusion defect of at least one segment (16 segment model) or no defect vs persistent defect in patients with anterior acute myocardial infarction was associated with improved global left ventricular function at 4 weeks; mean global wall motion score index 1.29 +/- 0.21 vs 1.66 +/- 0.31 (P=0.009). Multiple regression analysis in patients with an anterior acute myocardial infarction revealed that the extent of the perfusion defect at MCE3 was a significant (P=0.0005) independent predictor for left ventricular recovery at 4 weeks follow-up. The only other independent predictor was TIMI flow grade 3 post PTCA (P=0.007). Conclusion Intravenous myocardial contrast echocardiography immediately prior to primary PTCA seems safe and is capable of detecting the presence of a perfusion defect and its subsequent dynamic changes, particularly in patients with a first anterior acute myocardial infarction. A significant reduction in size of the initial perfusion defect using serial myocardial contrast echocardiography predicts functional recovery after 4 weeks and these findings underscore the potential diagnostic value of intravenous myocardial contrast echocardiography.