One-year outcome of patients after acute coronary syndromes (from the Canadian Acute Coronary Syndromes Registry)

Abstract

The objective of this study was to determine the management and outcome of less [corrected] selected patients with an acute coronary syndrome during hospitalization and up to 1 year after discharge. The Canadian Acute Coronary Syndromes Registry was a prospective observational study of patients admitted with suspected acute coronary syndromes. Data on demographic and clinical characteristics, in-hospital treatment, and outcomes were recorded. At 1 year, vital status, medication use, recurrent cardiac events, and procedures were determined by telephone contact. Of the 5,312 patients enrolled, 4,627 had a final diagnosis of acute coronary syndrome, with Q-wave myocardial infarction in 27.7%, non-Q-wave myocardial infarction in 33.2%, and unstable angina pectoris in 39.1%. During hospitalization, coronary angiography and revascularization were performed in 39.6% and 20.3% of patients, respectively. The in-hospital mortality rate was 2.4% overall. At discharge, 87.8%, 76.4%, 56.0%, and 54.8% of patients were prescribed aspirin, beta blockers, angiotensin-converting enzyme inhibitors, and lipid-lowering agents, respectively. Unadjusted 1-year mortality rates for hospital survivors were 6.5%, 10%, and 5.4% for those with Q-wave myocardial infarction, non-Q-wave myocardial infarction, and unstable angina pectoris groups, respectively (p <0.0001). This difference in mortality rate remained significant after adjusting for other prognosticators, whereas the use of coronary angiography and revascularization after discharge was similar across patients. At 1 year, fewer patients were maintained on aspirin and beta blockers, whereas the use of lipid-lowering therapy increased (all p <0.0001). Despite similar rates of coronary angiography and revascularization after discharge, patients with non-Q-wave myocardial infarction had worse outcomes at 1 year. Moreover, there was a significant opportunity to enhance the discharge and long-term use of evidence-based secondary prevention therapies.