Incidence of heart failure and mortality after acute coronary syndromes.

BACKGROUND The long-term incidence of heart failure (HF) in ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI), or unstable angina (UA) patients is uncertain. We examined the 1-year incidence of HF and its association with mortality among patients surviving their first acute coronary syndrome (ACS) hospitalization. METHODS AND RESULTS A retrospective cohort study of patients, aged ≥20 years, with no prior HF, hospitalized for the first time with ACS between April 1, 2002, and December 31, 2008, in Alberta, Canada, and followed up for 1 year. Index HF was defined as HF that developed as a complication during the index ACS hospitalization, and post-discharge HF, as HF developing after discharge from the index ACS hospitalization. Among 9,406 STEMI, 11,008 NSTEMI, and 4,910 UA patients, 13.6%, 14.8%, and 5.2% had index HF, respectively (P < .01). At 1-year, cumulative HF rates were 23.4% in STEMI, 25.4% in NSTEMI, and 16% in UA patients. Among hospital survivors, 1-year mortality rate was 13.9% in patients with index HF, 10.6% in patients with postdischarge HF, and 2.4% in patients with no HF. In multivariable analysis, both index HF (adjusted hazard ratio 3.2, 95% CI 2.7-3.7) and postdischarge HF (adjusted hazard ratio 4.6, 95% CI 3.9-5.4) were associated with 1-year mortality. CONCLUSIONS There are significant differences in the incidence of HF among STEMI, NSTEMI, and UA patients. The increased mortality risk associated with index HF and postdischarge HF suggests a need for vigilant follow-up of all ACS patients for prompt detection and treatment of HF.