Comparative Persistence on β-Blockers Versus Calcium Channel Blockers for Ventricular Rate Control in Nonelderly Patients With Atrial Fibrillation

Abstract

Background: For patients with atrial fibrillation (AF), early treatment is essential to prevent serious complications such as stroke. Several randomized clinical trials have shown that rate-control may be as effective as rhythm-control medications, whereas the latter have serious side effects. Little evidence exists, however, about which class of rate-control medication—β-blockers (BBs) or calcium channel blockers (CCBs)—may be superior. Objective: The objective was to compare the long-term persistence on BBs versus CCBs in nonelderly adult patients with AF. Methods: A longitudinal retrospective cohort study for patients 40 to 60 years old with newly diagnosed AF (identified by ICD-9 code 427.31) was performed using data from Ohio Medicaid physician, institutional, and pharmacy claims from January 2006 through June 2011. A Cox proportional hazard regression, with time to change out of rate-control therapy as the dependent variable, was estimated to compare persistence on (proxy for effectiveness of) rate-control medication across drug classes. A propensity-score analysis was used to control for selection bias. Additional covariates included age, development of heart failure, and medication adherence. Results: Out of 1239 patients included in the cohort, 1016 received a BB; 223 received a CCB. Over time, patients on CCBs were significantly more likely to switch out of rate-control therapy (hazard ratio = 1.89; 95% CI = 1.14-3.09) than patients on BBs. Conclusions: Evidence suggests that nonelderly AF patients, when prescribed rate-control therapy, persist longer on BBs than CCBs. Because this is the first long-term study comparing the 2 drug classes in the nonelderly population, further research is suggested.