The accuracy of deceleration time of diastolic coronary flow measured by transthoracic echocardiography in predicting long-term left ventricular infarct size and function after reperfused myocardial infarction

Assessment of microvascular function after reperfused acute myocardial infarction (AMI) provides important insights for myocardial reperfusion and facilitates prediction of long-term left ventricular (LV) function and clinical outcome. In this study, we examined microvascular integrity 48 h after successful primary percutaneous coronary intervention (PCI) and compared predictive accuracy of the intracoronary pressure-wire- and transthoracic Doppler echocardiography-based parameters in the estimation of long-term LV infarct size and function. The study group consisted of 30 anterior AMI patients who were treated successfully with primary PCI. Two days after primary PCI, microvascular integrity was evaluated. Coronary flow reserve (CFR), collateral flow index (CFIp), coronary wedge pressure (CWP), and index of microvascular resistance (IMR) were determined using intracoronary pressure wire. Deceleration time of coronary diastolic flow (DDT) was measured using transthoracic echocardiography. At 6 months, coronary angiography, echocardiography, and infarct size measurement were performed. Area under the curve, sensitivity, and specificity of the indices of microvascular perfusion in the prediction of late-term infarct size were as follows: IMR (0.68 +/- 0.15, 69%, 60%), CFR (0.67 +/- 0.10, 66%, 59%), CWP (0.69 +/- 0.12, 70%, 72%), CFIp (0.64 +/- 0.10, 65%, 78%), and DDT (0.68 +/- 0.16, 69%, 79%). All of the microvascular perfusion indices, which have been used in this study, had comparable sensitivity and specificity in the prediction of long-term ejection fraction. There were no significant differences between areas under the curve of microvascular perfusion indices in the prediction of long-term infarct size and ejection fraction. As a non-invasive parameter, DDT was found to be as accurate as the invasive parameters of microvascular function in estimating long-term infarct size and LV function. Thus, simply measuring DDT in the reperfused infarct-related artery might provide useful and reliable estimate for early risk stratification.