Propafenone‐ vs. amiodarone‐associated adverse cardiac outcomes in patients with atrial fibrillation and heart failure

Aims Clinical trials have shown an increased risk of death in patients with recent myocardial infarction who received antiarrhythmic drugs such as flecainide, encainide or moricizine, especially in the presence of associated structural heart disease such as cardiac dysfunction. This study aimed to evaluate the safety outcomes of propafenone use in atrial fibrillation patients with heart failure when compared to those of amiodarone use. Methods This population‐based cohort study used the National Health Insurance Research Database in Taiwan. Eligible patients were those who had atrial fibrillation or atrial flutter diagnosis, had heart failure diagnosis, and first received propafenone or amiodarone between 2002 and 2018. The primary endpoints were death due to arrhythmia and the composite proarrhythmic outcome, which consisted of sudden cardiac arrest, arrhythmic death, ventricular arrhythmia and implantation of defibrillator. Results After propensity score matching, the study cohort consisted of 7235 propafenone and 14 470 amiodarone users. Compared to amiodarone, propafenone was associated with significantly lower risk of the composite proarrhythmic outcome (adjusted hazard ratio: 0.52; 95% confidence interval: 0.42–0.64; P < .001). Propafenone users also had lower risk of death owing to arrhythmia compared to amiodarone users (adjusted hazard ratio: 0.22; 95% confidence interval: 0.08–0.65; P = .006). Subgroup analysis and sensitivity analysis showed similar trends, favouring propafenone. Conclusion Propafenone was not significantly associated with increased risk of proarrhythmia and mortality when compared to amiodarone in atrial fibrillation patients with heart failure in contemporary real‐world settings. Prospective studies are needed to determine whether propafenone should definitely be avoided in these patients.