2025 Southeastern Residency Conference

Title: Use of Prophylactic Amiodarone for the Prevention of Atrial Fibrillation After Cardiac Surgery 


Authors: Savannah Salam, Sydney Davis, Michael Bitonti, Lisa Curran, Paul Weldner 


Objective: Discuss the potential benefit of routine oral amiodarone use for atrial fibrillation prophylaxis after cardiovascular surgery


Self Assessment Question: True or False: The use of oral amiodarone for atrial fibrillation prophylaxis should replace prophylactic beta blocker use in patients after cardiac surgery


Background: Amiodarone is a Vaughan-Williams Class III antiarrhythmic agent approved for the management of life-threatening ventricular arrhythmias but is commonly used for treatment of atrial fibrillation (Afib). Approximately 15-40% of patients develop postoperative Afib after cardiac surgery. The PAPABEAR trial found a significant reduction of postoperative Afib with oral amiodarone prophylaxis in patients undergoing nonemergent coronary artery bypass graft (CABG) and/or valve replacement/repair with or without beta blocker use. The 2023 ACC/AHA/ACCP/HRS Atrial Fibrillation Guidelines added a level IIa recommendation for the use of short-term prophylactic beta blockers or amiodarone in patients undergoing cardiac surgery who are at high risk for developing postoperative Afib. Our institution recently began use of amiodarone prophylaxis in select patients at surgeon discretion. The purpose of this review is to evaluate the impact of oral amiodarone for Afib prophylaxis after cardiac surgery. 

Methods: This review was a single center, IRB reviewed, determined exempt, retrospective comparator evaluation conducted from July 1, 2024 to February 28, 2025. Adult patients who underwent CABG, valve replacement, or valve repair were included in this study. Patients were excluded if they had a history of Afib in the last 12 months, amiodarone use in the last 6 months, were on Vaughan- Williams Class I or III antiarrhythmic medications prior to procedure, required mechanical circulatory support, or if any ventricular or atrial arrhythmia was present before the procedure. Each patient was reviewed for demographic data, type of cardiac procedure, use of prophylactic amiodarone, development of Afib postoperatively, use of prophylactic beta blocker, and development of Afib or Aflutter within 30 days of hospital discharge. Included patients were stratified by use of prophylactic oral amiodarone. The prophylactic amiodarone standard order was 400 mg twice daily for five days. The length of amiodarone treatment and dose were adjusted based on clinical decision-making by the care team. The primary outcome was the incidence of postoperative Afib. Secondary outcomes include time to postoperative Afib, use of intravenous amiodarone, percentage of patients that discontinued prophylactic amiodarone, and readmission for atrial arrhythmias within 30 days of discharge from the index event.  

Results: Of the 126 patients screened, 80 patients were included in this study. There were 30 patients in the amiodarone prophylaxis group and 50 patients in the standard of care group. Baseline patient characteristics were balanced between groups apart from smoking history (16% in amiodarone group vs. 70% in standard of care), history of heart failure (14% vs. 36%), and index event including a valve procedure (70% vs. 32%). Notably all patients received prophylactic beta-blockers per standard practice at our facility. The primary outcome occurred in 23.3% of the amiodarone prophylaxis group vs. 42% in the standard of care group (OR 0.42, 95% CI 0.15-1.14, p=0.09). There were no significant differences in the average time to postoperative Afib (78.8 hrs vs. 70 hrs, p=0.13) and average length of hospital stay (172.1 hrs vs. 154.2 hrs, p=0.39). Rates of post-discharge atrial arrhythmias were 13.3% in amiodarone group vs. 4.0% in standard of care (p=0.13). In the amiodarone prophylaxis group, 3 patients discontinued amiodarone therapy, and 4 patients required a dose-reduction in amiodarone due to reported hypotension, heart block, and nausea.

Conclusions: The use of oral amiodarone prophylaxis may provide a strategy to reduce the incidence of atrial fibrillation after cardiac surgery. This intervention was well tolerated, though it would require further investigation to achieve statistical significance.