Background: The prognostic impact of heart failure (HF) developing after myocardial infarction (MI) according to preserved/reduced ejection fraction (EF) and the timing of its occurrence is incompletely quantified in the current era.
Methods and Results: All Olmsted County, Minnesota residents (n=2,596) with incident MI diagnosed in 1990-2010 and no prior HF were followed through March 2013. Cox proportional hazards models were used to examine (1) the hazard ratios (HRs) for death associated with HF type and timing; and (2) secular trends in survival by HF status. During a mean follow-up of 7.6 years, 902 patients developed HF (425 within 3 days: “early-onset”) and 1,116 died. After adjustment for age and sex, HF as a time-dependent variable was strongly associated with mortality (HR=3.31, 95% confidence interval [CI]: 2.93-3.75), particularly from cardiovascular causes (HR=4.20, 95% CI: 3.50-5.03). Further adjustment for MI severity and comorbidity, acute treatment, and recurrent MI moderately attenuated the association (HR=2.49 and 2.94 for all-cause and cardiovascular mortality, respectively). Mortality did not differ by EF, but was higher for late- vs. early-onset HF (P for heterogeneity=0.002). The age- and sex-adjusted 5-year survival estimates in 2001-2010 vs. 1990-2000 were 82% and 81% among HF-free and 61% and 54% among HF patients, respectively (P for heterogeneity of trends=0.05). The age- and sex-adjusted HR for mortality in 2001-2010 vs. 1990-2000 was 0.77 (95% CI: 0.65-0.92).
Conclusions: HF markedly increases the risk of death after MI. This excess risk is similar regardless of EF but greater for late- vs. early-onset HF. Mortality after MI declined over time, primarily as a result of improved HF survival.
