Can coronary blood flow velocity pattern after primary percutaneous transluminal coronary angiography predict recovery of regional left ventricular function in patients with acute myocardial infarction?

Background-In the era of primary percutaneous transluminal coronary angiopl asty (PTCA), it is important to judge whether myocardium within acute ische mic injury is viable. This study sought to investigate parameters derived f rom the coronary blood flow velocity spectrum immediately after primary PTC A in patients with acute myocardial infarction and to elucidate the clinica l value of coronary blood flow measurement in predicting myocardial viabili ty. Methods and Results-Using a Doppler guidewire, we measured coronary blood f low velocity after successful completion of primary PTCA in 23 consecutive patients with acute anterior myocardial infarction. Regional wall motion wa s analyzed to estimate anterior wall motion score index (A-WMSI) by echocar diography before PTCA and 1 month after the onset of symptoms. Average syst olic peak velocity (ASV) and deceleration time of diastolic flow velocity ( DDT) significantly correlated to 1-month A-WMSI (r= -0.54, P=0.007 and r=-0 .62, P=0.002, respectively), and optimal cutoff values to predict viable my ocardium (defined as 1-month A-WMSI less than or equal to 2.0) were 6.5 cm/ s for ASV and 600 ms for DDT (sensitivity=0.79, specificity=0.89 and sensit ivity=0.86, specificity=0.89, respectively). ASV and DDT also correlated we akly to the change in A-WMSI(r=0.46, P=0.03 and r=0.49, P=0.02, respectivel y). Conclusions-Low ASV and rapid DDT of coronary blood flow spectrum immediate ly after primary PTCA reflects a greater degree of microvascular damage in the risk area. Analysis of coronary blood flow spectrum immediately after p rimary PTCA by use of a Doppler guidewire is useful in predicting recovery of regional left ventricular function.