Degree of residual stenosis in the culprit coronary artery after thrombolytic administration (Thrombolysis in Myocardial Infarction [TIMI] trials)

This study was undertaken to characterize residual stenosis after thromboly tic administration and to evaluate clinical and angiographic features and e arly outcomes of patients with mild residual obstruction after thrombolytic administration. Patients who underwent angiography at 90 minutes after thr ombolytic: administration in the Thrombolysis In Myocardial Infarction 4, 1 0A, 10B, and 14 trials were divided into 3 groups according to the degree o f residual stenosis measured by quantitative coronary angiography: patients with a patent culprit artery with <50% stenosis, patients with patent arte ries and residual stenosis greater than or equal to 50%, and patients with occluded arteries. Only 8.9% of the patients (188 of 2,119) had an infarct- related artery luminal diameter stenosis of <50% 90 minutes after thromboly sis. Compared with patients with patent arteries and greater than or equal to 50% stenosis, patients with mild residual obstruction were younger (56.8 vs 58.6 years; p = 0.03), had fewer prior myocardial infarctions (6.9% vs 13.3%; p = 0.01), fewer eccentric (19.8% vs 42.1%; p <0.0001), ulcerated (7 .5% vs 13.2%; p = 0.03), and collateralized (6.6% vs 13.2%, p = 0.01) lesio ns, but ct greater thrombus burden (29.7% vs 18.3%, p = 0.0002). Among pati ents with patent arteries, a residual stenosis of <50% was associated with a significantly lower composite of in-hospital death, myocardial infarction , and congestive heart failure (2.8% vs 7.1%, p = 0.03). Thus, a minority o f patients have a mild residual obstruction at 90 minutes after thrombolyti c administration. These patients have less complex lesions with greater thr ombus burdens and better clinical outcomes. (C) 2000 by Excerpta Medica, In c.