Canadian-American differences in the management of acute coronary syndromes in the GUSTO IIb trial - One-year follow-up of patients without ST-segment elevation

Background-Little information exists concerning practice patterns between C anada and the United States in the management of myocardial infarction (MI) patients without ST-segment elevation and unstable angina. Methods and Results-We examined the practice patterns and 1-year outcomes o f 2250 US and 922 Canadian patients without ST-elevation acute coronary syn dromes in the Global Use of Strategies to Open Occluded Coronary Arteries ( GUSTO) IIb trial. The US hospitals more commonly had on-site facilities for angiography and revascularization. These procedures were performed more of ten and sooner in the United States than Canada, whereas Canadian patients were more likely to undergo noninvasive stress testing. The length of initi al hospital stay was 1 day longer for Canadian than US patients. Recurrent and refractory ischemia was more common in Canada. One-year mortality was c omparable between the 2 countries. However, at 6 months, even after baselin e differences were accounted for, the (re)MI rate was significantly higher in Canadian than US patients with unstable angina (8.8% versus 5.8%, P=0.03 9), as was the composite rate of death or (re)MI (13.1% versus 9.1%, P=0.01 6), Conclusions-One-year mortality was comparable between Canada and the United States in both MI and unstable angina cohorts despite higher intervention rates in the United States. However, outcomes at 6 months among patients wi th unstable angina differed. Whereas more frequent coronary interventions w ere not associated with reduced recurrent MI or death among MI patients wit hout ST elevation, they may favorably affect outcomes in patients with unst able angina.