Incidence, treatment, and outcomes of atrial fibrillation complicating non-ST-segment elevation acute coronary syndromes

Background We assessed the incidence and timing of post-acute coronary syndrome (ACS) atrial fibrillation (AF) related and not related to coronary artery bypass grafting (CABG); described the use of antithrombotic therapy; and evaluated the association of AF with mortality. Methods We studied 9242 high-risk non-ST-segment elevation (NSTE) ACS patients enrolled in EARLY ACS. Logistic regression with a landmark approach examined the association between AF within 7 days post-ACS and 30-day death. Cox proportional hazards modeling assessed the association of AF with 1-year mortality. Results Overall, 551 patients (6.0%) had AF at a median of 4 (25th, 75th percentiles: 2, 8) days post-ACS. CABG-related AF occurred in 2.6% (N = 242) of the overall population, representing 44% of all AF episodes. At discharge, patients with AF received aspirin (87%), clopidogrel (48%), or warfarin (19%). Aspirin plus clopidogrel plus warfarin was used in 5.7% of the overall AF population and in 10.0% of patients with non-CABG-related AF. In-hospital AF within 7 days post-ACS was associated with an adjusted hazard ratio for death between 7 and 30 days of 4.83 (95% confidence interval, 3.06-7.62) as well as higher 1-year mortality (2.40 [1.90-3.03]). Conclusions Overall, AF complicated the in-hospital course of 6% of patients with NSTE ACS and was associated with substantially greater risk for 30-day and 1-year mortality. Most patients with AF did not receive oral anticoagulation at discharge, highlighting an unexplored area of antithrombotic therapy at hospital discharge in these high-risk patients.