MANAGEMENT OF UNSTABLE ANGINA-PECTORIS AND NON-Q-WAVE ACUTE MYOCARDIAL-INFARCTION IN THE UNITED-STATES AND CANADA (THE TIMI-III REGISTRY)

Management of Q-wave acute myocardiol infarction (AMI) has been shown to differ between the United States and Canada, with more catheterizat ion and revascularization procedures performed in the United States, b ut with little or no apparent difference in clinical outcomes. No prev ious studies have evaluated management differences for the acute coron ary syndromes of unstable angina pectoris and non-Q-wave AMI. We there fore compared treatments and outcomes between 14 United Stares and 4 C anadian tertiary care centers participating in an observational regist ry of all consecutive admissions for unstable angina or non-Q-wave AMI between 1990 and 1993. A random, stratified sample was selected for d etailed assessment and follow-up. There were 1,733 patients enrolled i n United States centers and 642 in Canadian ones. In United States cen ters patients were less likely to receive intravenous nitroglycerin, h eparin, beta blockers, calcium antagonists, or greater than or equal t o 2 anti-ischemic agents. Coronary arteriography during index hospital ization was equally frequent in both countries (63.4% vs 66.9%, p = 0. 781), but at 6 weeks and 1 year coronary arteriography was slightly le ss frequent in the United States patients. Revascularization by corona ry angioplasty or bypass surgery was equivalent at 6 weeks and 1 year; however, there were trends to-word less angioplasty and more bypass s urgery in the United States than in Canada. Patients at United States centers stayed in the hospital fewer days than patients at Canadian ce nters (mean 8.2 vs 12.1 days, p < 0.001). Death or AMI by 6 weeks was not different (4.8% vs 4.4%, p = 0.633), nor was it different at 1 yea r (10.0% vs 10.2%, p = 0.836). The combined outcome of death, AMI, or recurrent ischemia was more common in United States than in Canadian p atients at 6 weeks (18.4% vs 13.9%, p = 0.004). Our findings indicate that United States physicians and hospitals did not consistently utili ze more resources and were not more aggressive than their Canadian cou nterparts when treating acute coronary syndromes during this period. ( C) 1997 by Excerpta Medica, Inc.