Effect of Intravenous Amiodarone Versus Propranolol on Heart-Rate Control and Prevention of Postoperative Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Grafting

Shirin Fekry Abdelazim; Mohamed Osama Elsaid; Yousry Elsaied Rezk; Mahmoud Abd El Azim Mubark

Shirin Fekry Abdelazim Department of Critical Care, Faculty of Medicine, Banha University, Egypt
Mohamed Osama Elsaid Department of Critical Care, Faculty of Medicine, Banha University, Egypt
Yousry Elsaied Rezk Department of Critical Care, Faculty of Medicine, Banha University, Egypt
Mahmoud Abd El Azim Mubark Department of Critical Care, Faculty of Medicine, Banha University, Egypt

Keywords: Amiodarone, Propranolol, Inderal, Atrial Fibrillation, Coronary Artery Bypass Graft, Coronary Artery Disease, Beta-Blocker

Abstract

Background: Coronary artery disease (CAD) is the leading cause of cardiovascular mortality worldwide. This randomized controlled trial compared intravenous amiodarone and intravenous propranolol for heart-rate control and prevention of postoperative atrial fibrillation (AF) in patients undergoing isolated coronary artery bypass grafting (CABG).

Methods: Sixty adults with CAD undergoing CABG were randomized into two groups. Group A (n=30) received intravenous amiodarone (3 mg/kg) before aortic declamping, while Group B (n=30) received intravenous propranolol (1 mg, repeated as needed up to three doses). Baseline demographic, clinical, preoperative, and intraoperative characteristics were comparable between groups.

Results: Amiodarone was associated with significantly better early postoperative outcomes than propranolol. Thirty-day mortality was lower in the amiodarone group (0% vs. 13.3%, P=0.031), with fewer cases of renal dysfunction (0% vs. 13.3%, P=0.031), severe postoperative bleeding >1000 mL (3.3% vs. 23.3%, P=0.022), and cardiac complications (3.3% vs. 26.7%, P=0.026). Patients receiving amiodarone also had a shorter time to extubation (34.4 ± 10.0 vs. 39.6 ± 8.4 hours, P=0.033). However, the incidence of postoperative AF at 3 days, 1 week, and 4 weeks was similar between the groups (all P>0.05). Within the amiodarone group, postoperative AF was associated with prolonged ICU stay (P=0.03) and total hospital stay (P=0.001). Univariable analysis identified increased left atrial (LA) diameter and reduced left ventricular ejection fraction (LVEF) as significant predictors of postoperative AF. Multivariable analysis demonstrated that an LA diameter >45 mm was the only independent predictor (P=0.007), while reduced LVEF showed a borderline association (P=0.079).

Conclusions: Amiodarone and propranolol demonstrated comparable efficacy in preventing postoperative AF after isolated CABG. However, amiodarone was associated with superior early postoperative outcomes, including lower mortality, reduced renal dysfunction, shorter extubation time, and fewer bleeding and cardiac complications. An LA diameter >45 mm independently predicted postoperative AF, which was associated with longer ICU and hospital stays.