Importance: Whether the extent of coronary artery disease (CAD) is associated with the occurrence of heart failure (HF) after myocardial infarction (MI) is not known. Furthermore, whether this association might differ by HF type according to preserved or reduced ejection fraction (EF) has yet to be determined.
Objectives: To evaluate in a community cohort of patients with incident (first-ever) MI the association of angiographic CAD with subsequent HF and to examine the prognostic role of CAD according to HF subtypes: HF with reduced EF and HF with preserved EF.
Design, setting, and participants: A population-based cohort study was conducted in 1922 residents of Olmsted County, Minnesota, with incident MI diagnosed between January 1, 1990, and December 31, 2010, and no prior HF; study participants were followed up through March 31, 2013. The extent of angiographic CAD was determined at baseline and categorized according to the number of major epicardial coronary arteries with 50% or more lumen diameter obstruction.
Main outcomes and measures: The primary end point was time to incident HF. The primary exposure variable was the extent of CAD as expressed by the number of major coronary arteries with significant obstruction (0-, 1-, 2-, or 3-vessel disease) obtained from coronary angiograms performed no more than 1 day after the MI. Heart failure was ascertained by the Framingham criteria and classified by type according to EF (50% cutoff).
Results: Of the 1922 participants, 1258 (65.4%) were men (mean [SD] age, 64 [13] years). During a mean follow-up period of 6.7 (5.9) years, 588 patients (30.6%) developed HF. With death and recurrent MI modeled as competing risks, the cumulative incidence rates of post-MI HF among patients with 0 or 1, 2, and 3 diseased vessels were 10.7%, 14.6%, and 23.0% at 30 days; and 14.7%, 20.6%, and 29.8% at 5 years, respectively (P < .001 for trend). After adjustment for clinical characteristics in a Cox proportional hazards regression model, the hazard ratios (95% CIs) for HF were 1.25 (0.99-1.59) and 1.75 (1.40-2.20) in patients with 2 and 3 vessels vs 0 or 1 occluded vessel, respectively (P < .001 for trend). The increased risk with a greater number of occluded vessels was independent of the occurrence of a recurrent MI and did not differ appreciably by HF type.
Conclusions and relevance: The extent of angiographic CAD is an indicator of post-MI HF regardless of HF type and independent of recurrent MI. These data underscore the need to further investigate the processes taking place in the transition from myocardial injury to HF.