Anticoagulation and amiodarone for new atrial fibrillation after coronary artery bypass grafting: Prescription patterns and 30-day outcomes in the United States and Canada

Objective: We sought to elucidate national practice patterns regarding anticoagulation and antiarrhythmic medication use at discharge and examine short-term patient outcomes. Methods: In this retrospective cohort study, we analyzed the data of patients from the Society of Thoracic Surgeons Adult Cardiac Surgery Database from July 2011 to June 2018 who underwent first-time isolated coronary artery bypass graft surgery (CABG) and developed new post-CABG atrial fibrillation (AF) without significant complications. In total, 166,747 patients met study criteria. We examined 30-day outcomes. Results: In total, 166,747 patients were analyzed and divided into 4 groups based on discharge medications: amiodarone with or without anticoagulation, anticoagulation alone, and neither. Demographic characteristics were similar among the 4 groups. In total, 25.7% of patients were discharged on anticoagulation with an average CHA(2)DS(2)-VASc score of 3.2 +/- 1.3. Anticoagulation use at discharge was not associated with lower 30-day stroke readmissions (adjusted odds ratio [AOR], 0.87; 95% confidence interval [CI], 0.65-1.16; P = .35). Adjusted 30-day readmissions for major bleeding were significantly more common in anticoagulated patients (AOR, 4.30; 95% CI, 3.69-5.03; P < .0001). Among those discharged off anticoagulation, there was no significant difference in adjusted 30-day stroke rates based on amiodarone use at discharge (AOR, 1.19; 95% CI, 0.85-1.66; P = .31). Conclusions: Post-CABG anticoagulation for new AF is associated with increased bleeding and no difference in stroke at 30 days. Prospective randomized studies are needed to formalize safe and efficacious short- and long-term management strategies.