Antiarrhythmic Drug Use in Patients 65 Years of Age With Atrial Fibrillation and Without Structural Heart Disease

摘要

Little is known in clinical practice about antiarrhythmic drug (AAD) use in atrial fibrillation (AF) patients (particularly younger ones) that do not have structural heart disease. Using the MarketScan^® database, we identified patients <65 years of age without known coronary artery disease or heart failure who had an AAD prescription claim (Class Ic drug, amiodarone, sotalol, or dronedarone) after their first AF encounter. A multinomial logistic regression model was created to assess factors associated with using each available AAD, compared with using Class Ic drugs before and after dronedarone was marketed in the United States. Additionally, we used the Kaplan Meier method to determine the rates of change in AAD use and discontinuation during the year post-AAD initiation. Of 8562 AF patients, 35% received Class Ic drugs, 34% amiodarone, 24% sotalol, and 7% dronedarone. The median patient age was 56 (IQR 49, 61) and 34% were female. Both before and after dronedarone was marketed, there was a statistically significant lower likelihood of Class Ic drug use versus other AAD use with increasing age, inpatient index AF encounter, and prior or concomitant anticoagulation therapy. During the 1 year post-AAD initiation, the AAD change rate was 14% for Class Ic drugs, 8% amiodarone, 17% sotalol, and 18% dronedarone (p<0.001); the AAD discontinuation rate was 40% for Class Ic drugs, 52% amiodarone, 40% sotalol, and 69% dronedarone (p<0.001). In conclusion, we found extensive use of amiodarone that may be inconsistent with guideline recommendations, and unexpectedly high rates of AAD discontinuation.