Limited duration of antiarrhythmic drug use for newly diagnosed atrial fibrillation in a nationwide population under age 65.

Introduction Antiarrhythmic drugs (AADs) are commonly used for the treatment of newly-diagnosed symptomatic atrial fibrillation (AF), however initial AAD choice, duration of therapy, rates of discontinuation and factors associated with a durable response to therapy are poorly understood. This study assesses initial choice and duration of antiarrhythmic drug therapy in the first two years after diagnosis of atrial fibrillation in a younger, commercially-insured population. Methods A large nationally-representative sample of patients age 20 to 64 was studied using the IBM MarketScan Database. Patients who started an AAD within 90 days of AF diagnosis with continuous enrollment for 1 year pre-index diagnosis and 2 years post-index were included. A Cox proportional hazards model was used to determine factors associated with AAD discontinuation. Results Flecainide was used most frequently (26.8%), followed by amiodarone (22.5%), dronedarone (18.3%), sotalol (15.8%), and propafenone (14.0%), with other AADs used less frequently. Twenty-two percent of patients started on an AAD underwent ablation within 2 years, with 79% discontinuing the AAD after ablation. Ablation was the strongest predictor of AAD discontinuation (HR: 1.70; CI: 1.61 - 1.80), followed by male gender (HR: 1.10; CI: 1.02 - 1.19). Older patients (HR: 0.76; CI: 0.72 - 0.80; reference age 18-49) and those with comorbidities, including cardiomyopathy (HR: 075; CI: 0.61 - 0.91), diabetes (HR: 0.83; CI: 0.75 - 0.91) and hypertension (HR: 0.87; CI: 0.81 - 0.94) were less likely to discontinue AADs. Conclusion Only 31% of patients remained on the initial AAD at 2 years, with mean duration of initial therapy 7.6 months prior to discontinuation. Unstructured abstract Antiarrhythmic drugs (AADs) are commonly used for the treatment of newly-diagnosed atrial fibrillation, but practice patterns and duration of treatment is poorly understood. This study examined AAD initiation in a young, commercially-insured population. Flecainide was used most frequently (26.8%), followed by amiodarone (22.5%), with other AADs used less frequently. Only 31% of patients remained on the initial AAD at 2 years, with an average duration of therapy of 7.6 months before discontinuation. This article is protected by copyright. All rights reserved.