Acute myocardial infarction in Alberta: Temporal changes in outcomes, 1994 to 1999

BACKGROUND: The current survival trends in patients with acute myocardial infarction (AMI) are not known. A population-based study using administrative data to examine the short and long term survival of patients after AMI in Alberta between 1994 and 1999 was conducted. METHODS: AMI patients were identified from hospital discharge data. Temporal changes in the adjusted (age, sex, AMI anatomical location and comorbidities) fatality rate were analyzed in 19,928 AMI patients. RESULTS: The age- and sex-adjusted incidence of hospitalization for AMI in Alberta significantly declined from 169.6 per 100,000 population in 1994 to 160.8 per 100,000 in 1999 (P=0.03). The risk-adjusted in-hospital case fatality rate from all causes was 11.4% (95% CI 10.6% to 12.3%) in 1994 versus 9.2% (8.4% to 10.1%) in 1999; the 30-day case fatality rate was 12.6% (11.7% to 13.6%) in 1994 versus 10.1% (9.1% to 11.0%) in 1999; and the one-year case fatality rate was 19.0% (17.8% to 20.1%) in 1994 versus 14.9% (13.8% to 16.0%) in 1999. The percentage of hospitalized AMI patients who underwent coronary angiography within one year after admission rose from 48.2% in 1994 to 52.4% in 1999; percutaneous transluminal coronary angioplasty increased from 25.5% to 35.0% and coronary artery bypass surgery increased from 9.7% to 12.6%. Prescriptions for pharmacological drugs at discharge increased from 1994 to 1999 among patients aged 65 and older: from 29.5% in 1994 to 41.0% in 1999 for beta-blockers, from 5.2% to 18.7% for lipid lowering agents and from 14.0% to 20.5% for angiotensin-converting enzyme inhibitors. INTERPRETATION: There was a modest improvement in patient survival after AMI between 1994 and 1999. The improvements may be associated with increasing use of revascularization and pharmacological therapy provided in the management of AMI.