DIFFERENCES IN THE TREATMENT OF MYOCARDIAL-INFARCTION IN THE UNITED-STATES AND CANADA - A COMPARISON OF 2 UNIVERSITY HOSPITALS

Objective: To compare practice patterns and clinical outcomes for a co stly yet common condition, acute myocardial infarction. Design: Retros pective cohort study in two university hospitals (Stanford [Calif] Uni versity and McGill University, Montreal, Quebec) and a patient survey. Patients: All consecutive patients (n=518) treated for acute myocardi al infarction in the coronary care unit of those two hospitals over 2 years. Measures: Rates of diagnostic and therapeutic procedures, morta lity, reinfarction, and level of functional status (by chart review an d patient survey). Results: Demographic and clinical characteristics w ere similar for the two groups. Noninvasive tests were more common at McGill (exercise tests, 56% vs 20%; tests of left ventricular function , 86% vs 59%; P<.0001 for both). In contrast, invasive procedures were more common at Stanford (angiography, 55% vs 34%; angioplasty, 30% vs 13%, and bypass surgery, 10% vs 4%; P<.0001). At a median follow-up o f 20 months, reinfarction and mortality rates were similar at Stanford and McGill (13% vs 8% and 28% vs 27%, respectively; P>.05 for both). In contrast, the angina rate was slightly lower at Stanford (33% vs 40 %; P=.15), and the functional status of Stanford patients was better t han that of McGill patients (mean Duke Activity Status Index score, 28 .8 and 22.9, respectively; P=.006). This functional status difference persisted after adjustment for differences in clinical factors, includ ing coronary revascularization. Conclusion: The aggressive treatment o f the American patients with myocardial infarction did not improve rei nfarction and mortality rates compared with the conservative treatment of the Canadian patients. The superior functional status of the Ameri can patients merits further investigation.