Abstract 15919: Adverse Outcomes Related Amiodarone Toxicity in Early Rhythm Control of Patients With Atrial Fibrillation: A Nationwide Cohort Study

Abstract

Background: Early rhythm control therapy was associated with a lower risk of adverse cardiovascular outcomes than usual care among patients who had recently (within 1 year) been diagnosed with atrial fibrillation (AF). In real-world data, the most commonly selected initial rhythm control strategy was the Class III anti-arrhythmic drug (AAD) amiodarone, but adverse outcomes related amiodarone toxicity was not well reported in this population. This study sought to investigate the fatal and non-fatal adverse outcomes related amiodarone toxicity in early rhythm control of patients with AF. Methods: Using the database of Korean National Health Insurance Service, we analyzed the adverse outcomes related amiodarone toxicity in 140,908 (rhythm control: 57,148, rate control: 83,760) patients with AF undergoing rhythm control or rate control therapy, initiated within 1 year of AF diagnosis, between 2005 and 2015. Results: The most commonly used rhythm control strategy was the class III drug amiodarone (22,877 (40.0%) of 57,148 patients in early rhythm control), followed by class Ic drugs. Patients with amiodarone for initial rhythm control strategy showed higher rate of interstitial lung disease (1.43% vs. 0.75%, p<0.001), sudden cardia arrest duet to Torsade de Pointes (0.31% vs. 0.17%, p=0.001), and hypothyroidism (16.5% vs. 8.12%, p<0.001). But incidence rate of bradycardia needing a temporary pacemaker, bradycardia needing a permanent pacemaker, and toxic hepatitis were higher in early rhythm control patients with other AADs compared to patients with amiodarone. Conclusions: The most commonly used rhythm control strategy was amiodarone in AF patients undergoing early rhythm control. Using amiodarone for the initial rhythm control strategy showed a higher rate of interstitial lung disease, sudden cardia arrest duet to Torsade de Pointes, and hypothyroidism. Attention should be paid to amiodarone toxicity in selecting rhythm control strategy for these patients.