Abstract 13898: A Comparison of Rate Control Agents in Patients With Atrial Fibrillation: Follow-up Investigation of Affirm Study

Abstract

Introduction: There is limited data from randomized controlled trials comparing rate control agents in patients with atrial fibrillation (AF). We used patient-level data from the AFFIRM trial to compare outcomes in patients randomized to the rate control arm who were treated with a single rate control agent at baseline, including beta-blockers (BB), calcium channel blockers (CCB), or digoxin. Methods: Patient-level data from the AFFIRM trial was provided through the NHLBI BioLINCC biologic specimens and data repository information coordinating center. Different data sets were used to obtain the data for analysis. The independent variable for this analysis was the initial study drug used, which was classified as BB, CCB, or digoxin. The dependent variables were time to first hospitalization and time to death. Cox proportional hazards survival models were used to control for baseline differences between groups. Results: We analyzed 1144 out of 2027 participants assigned to the rate control group who were on a single rate control agent at the start of the trial. 485 (42.5%) participants were in the BB group, 344 (30%) in the CCB group, and 315 (27.5%) in the digoxin group. The mean age was 69.6 ± 8.0 and the majority of participants (62.9%) were male. Significant differences in baseline characteristics were present between groups, including sex, history of heart disease, left ventricular (LV) ejection fraction, LV diastolic dimension, and history of pulmonary disease. Hospitalization and death occurred in 55.9% and 12.5% of those in the BB group, 58.4% and 16.7% in the CCB group, and 55.2% and 21.1% in the digoxin group, respectively. After adjustment for differences in baseline characteristics, there were no significant differences in time to hospitalization or death for any group compared to another. Conclusions: In the AFFIRM trial, the initial rate control drug used was not associated with statistically significant differences in time to hospitalization or death after controlling for differences in baseline characteristics. There is limited data at present to guide the selection of rate control agents in patients with AF.