MYOCARDIAL PERFUSION PATTERNS RELATED TO THROMBOLYSIS IN MYOCARDIAL-INFARCTION PERFUSION GRADES AFTER CORONARY ANGIOPLASTY IN PATIENTS WITHACUTE ANTERIOR WALL MYOCARDIAL-INFARCTION

Background Epicardial coronary flow is occasionally reduced even after coronary intervention despite the absence of vessel obstruction in pa tients with acute myocardial infarction. Our aim was to clarify the ca use and outcomes of radiocontrast slow filling in patients with reperf used acute anterior myocardial infarction by assessing microvascular d amage with the use of myocardial contrast echocardiography (MCE) and f unctional outcomes. Methods and Results We carefully reviewed the cine angiograms of 86 patients who achieved coronary revascularization with in 12 hours of the onset and underwent MCE before and soon after recan alization with the intracoronary injection of sonicated microbubbles. Antegrade coronary flow after recanalization was graded by two observe rs based on Thrombolysis in Myocardial Infarction (TIMI) trial flow gr ades. Left ventricular ejection fraction was measured on the day of in farction and 1 month later. TIMI grade 2 was observed in 18 patients ( 21%), and the other 68 patients manifested TIMI grade 3 after recanali zation. All patients with TIMI 2 showed substantial MCE no reflow, whe reas only 11 patients (16%) with TIMI 3 showed MCE no reflow. Function al improvement was worse in patients with TIMI 2 than in those with TI MI 3 (TIMI 2, 38+/-8% versus 40+/-8%, P=NS [acute versus late]; TIMI 3 , 44+/-13% versus 55+/-13%, P<.001). Among patients with TIMI 3, signi ficant functional improvement was observed only in patients with MCE r eflow (MCE reflow, 46+/-13% versus 57+/-12%, P<.001; MCE no reflow, 35 +/-11% versus 45+/-12%, P=NS). Conclusions Despite no obstructive lesi on of the vessel, TIMI 2 is caused by advanced microvascular damage an d is a highly specific, although not sensitive, predictor of poor func tional outcomes in patients with acute myocardial infarction. TIMI 3 d oes not necessarily indicate myocardial salvage, and detection of MCE no reflow in these patients is particularly useful for the prediction of functional outcome.