Patterns of Amiodarone use and outcomes in clinical practice for atrial fibrillation

Abstract Background Amiodarone is the most effective antiarrhythmic drug (AAD) for atrial fibrillation (AF), but it has a high incidence of adverse effects. Methods Using the ORBIT AF registry, patients with AF on amiodarone at enrollment, prescribed amiodarone during follow-up, or never on amiodarone were analyzed for the proportion treated with a guideline-based indication for amiodarone, the variability in amiodarone use across sites, and the outcomes (mortality, hospitalization, and stroke) among patients treated with amiodarone. Hierarchical logistic regression modeling with site-specific random intercepts compared rates of amiodarone use across 170 sites. A logistic regression model for propensity to receive amiodarone created a propensity-matched cohort. Cox proportional hazards modeling, stratified by matched pairs evaluated the association between amiodarone and outcomes. Results Among 6987 AF patients, 867 (12%) were on amiodarone at baseline and 451 (6%) started on incident amiodarone during the 3-year follow-up. Use of amiodarone varied among sites from 3% in the lowest tertile to 21% in the highest (P  Conclusions Use of amiodarone among AF patients in community practice is highly variable. More than 2 out of 3 patients treated with amiodarone appeared to be eligible for a different AAD.