Coronary Ischemic Events after First Atrial Fibrillation: Risk and Survival

Purpose: We aimed to determine the long-term, gender-specific incidence and mortality risk of coronary ischemic events after first atrial fibrillation (AF). Methods: In this longitudinal cohort study, adult residents of Olmsted County, Minnesota, with an electrocardiogram-confirmed AF first documented in 1980 to 2000 and without prior coronary heart disease, were followed to 2004. The primary outcome was first coronary events (angina with angiographic confirmation, unstable angina, nonfatal myocardial infarction, or coronary death). Sex-specific incidence of coronary ischemic events and survival after development of such events were assessed using Cox proportional hazards modeling. Kaplan-Meier estimates of risks for coronary ischemic events were compared with those predicted by the Framingham equation. Results: Of the 2768 subjects (mean age 71 years, 48% were men), 463 (17%) had a first coronary event during a follow-up of 6.0 ± 5.2 years. The unadjusted incidence was 31 per 1000 person-years, and there was no difference between men and women. The incidence was higher in men (hazard ratio 1.32, P = .004) after adjusting for age. The 10-year event estimates were 22% and 19% in men and women, respectively, by our Kaplan-Meier analyses, and 21% and 11%, respectively, by Framingham risk equation. The mortality risk after coronary events was higher in women (hazard ratio 2.99 vs 2.33; P = .044), even after multiple adjustment. Conclusions: First AF marks a high risk for new coronary ischemic events in both men and women. AF conferred additional risk for coronary events beyond conventional risk prediction in women only. The excess mortality risk associated with the development of coronary events was significantly greater in women.