Amiodarone Prophylaxis for Atrial Fibrillation after Coronary Bypass—12 Years Follow-Up

Cecilie Enevoldsen,Sara Schoedt Riber,Lars Schoedt Riber,Britt Borregaard

doi:10.4236/ojts.2020.101003

Cecilie Enevoldsen, Sara Schoedt Riber + Show 2 more

Open Access

https://doi.org/10.4236/ojts.2020.101003

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Abstract

Objectives: Postoperative atrial fibrillation (POAF) is a common complication after cardiac surgery and might be avoided with amiodarone prophylaxis. We investigated the long-term effect of prophylactic amiodarone, in patients undergoing isolated, elective coronary artery bypass grafting (CABG), as well as the long-term prognosis of patients with POAF. Methods: We retrospectively analysed patients included in the randomized, control trial RASCABG allocated to either placebo or amiodarone as POAF prophylaxis. Several outcomes were evaluated using national databases. Patients were stratified and compared by prophylactic groups and rhythm. Cox proportional hazard analysis was used for multivariable analysis. Kaplan-Meier survival curves were constructed to assess the probability of survival and cumulative incidence curves. Results: Prophylactic amiodarone was not related to long-term side effects in comparison to placebo. Patients who developed POAF, were more likely to develop late AF, and had a worse overall survival. There was no difference in the overall survival between prophylactic groups. In the competing risk analysis, amiodarone and POAF was not associated with an increased risk of readmission, but POAF was associated with an increased risk of late AF HR 2.28 [95% CI 1.15; 4.55]. In the multivariable analysis, amiodarone was not associated with late AF, readmission or long-term mortality. Further, no association was found between POAF and late AF, readmission or long-term mortality. Conclusion: Amiodarone is a safe drug for the prevention of POAF in the RASCABG-setting. POAF is related to long-term worse prognosis regarding late AF and mortality.

Highlights

Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery with a reported incidence of 15% - 80%, depending on patient characteristics, surgical procedure, surveillance methods and definition of atrial fibrillation (AF) [1] [2] [3] [4]
In the competing risk analysis, amiodarone and POAF was not associated with an increased risk of readmission, but POAF was associated with an increased risk of late AF HR 2.28 [95% CI 1.15; 4.55]
POAF was associated with an increased risk of late AF HR 2.28 [95% CI 1.15; 4.55], when accounting for death as a competing risk

Summary

Introduction

Postoperative atrial fibrillation (POAF) is a common complication following cardiac surgery with a reported incidence of 15% - 80%, depending on patient characteristics, surgical procedure, surveillance methods and definition of atrial fibrillation (AF) [1] [2] [3] [4]. The underlying pathophysiology and aetiology of POAF remain unclear, studies have reported causes of a multifactorial nature, involving inflammation, oxidative stress, electrolyte disturbances, atrial dilation, age-related fibroses, pre-existing structural remodelling and increased sympathetic tone postoperatively [1] [3] [4]. In 2004-2005, the Danish randomized control trial, RASCABG, was conducted, in which 250 patients undergoing elective, solitary CABG were allocated to receive either amiodarone or placebo, as prophylaxis for POAF with a follow-up of 30-days [12]. No studies have yet investigated the long-term effect or side-effects of amiodarone on POAF following CABG

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