Prediction of early recurrent myocardial ischemia and coronary reocclusion after successful thrombolysis: A qualitative and quantitative angiographic study

Abstract

To determine the association of qualitative and quantitative measurements of the myocardial infarct-related coronary narrowing with subsequent recurrent ischemia/reocclusion after successful thrombolysis, 47 patients treated with high-dose (150 mg) tissue plasminogen activator over 6 to 8 hours were studied in the setting of acute myocardial infarction. No patient underwent emergent coronary angioplasty. All patients had Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow or higher at the baseline (90-minute) angiogram; 31 patients had a protocol 24-hour catheterization as well. Eighteen patients had recurrent ischemia/reocclusion whereas 29 had an uneventful hospital course. There was no significant difference in baseline clinical characteristics between the 2 groups. Twenty-five (86%) of those with an uneventful course had TIMI grade 3 flow at baseline angiogram compared with 56% of patients with recurrent events. No significant difference in angiographic morphologic characteristics was found between the 2 groups at baseline catheterization. At 24 hours, however, none of the patients who subsequently had recurrent events had a concentric narrowing, while 13 (58%) of them had a complex morphology. In contrast, quantitative parameters of minimal lumen diameter, percent area stenosis and percent diameter stenosis at baseline and 24 hours were not significantly different between those who did and did not have recurrent ischemia/reocclusion. These findings suggest that the degree and quality of coronary flow at baseline catheterization are more important determinants of sustained patency and event-free hospitalization than are quantitative dimensions or coronary morphology. In addition, narrowings that fail to become concentric within the first 24 hours are more likely to be associated with subsequent ischemia or reocclusion during the early periinfarct period.