Hospitalization rates differ depending on antiarrhythmic drug use

A claims database analysis of patients with atrial fibrillation (AF) who were prescribed an antiarrhythmic drug (AAD) found that those who took amiodarone had the lowest risk of hospitalization. Meanwhile, patients who received dronedarone had the highest risk of being hospitalized.

Lead researcher Nancy M. Allen LaPointe, PharmD, of the Duke Clinical Research Institute in Durham, N.C., and colleagues published their findings online March 31 in Circulation: Cardiovascular and Outcomes. They said there were approximately 479,000 hospital discharges with a primary diagnosis of AF in the United States in 2013.

The researchers analyzed data from the Thomson Reuters MarketScan commercial claims and encounters database, which included inpatient, outpatient and prescription claims data from U.S. employers. They examined patients who had AF but did not have coronary artery disease or heart failure.

To be eligible for this study, patients had to be younger than 65 years of age and had to receive their first AAD medication within 14 days of having AF. The first AF encounter occurred between Jan. 1, 2006, and Dec. 31, 2010, and patients who had less than six months of continuous health plan enrollment before experiencing AF were excluded.

The researchers reviewed prescription claims for Class Ic  (propafenone and flecainide) and Class III (amiodarone, sotalol and dronedarone) AADs. They identified the four groups as those taking the Class Ic drugs and those taking amiodarone, sotalol or dronedarone.

The study cohort included 8,562 patients. The median age was 56, while 34 percent of the patients were female and 69 percent were hospitalized for their first AF encounter.

The risk of hospitalization for AF was higher for dronedarone compared with the other three groups. Further, the risk was lower with amiodarone compared with the Class Ic and sotalol groups, while the risk of cardiovascular hospitalization was lower with amiodarone compared with the Class Ic drugs.

All-cause hospitalization rates were similar between patients who received Class Ic drugs, amiodarone and sotalol.

The researchers noted that the results should be interpreted with caution because they did not examine the reasons for different hospitalization rates such as side effect and efficacy differences.