Po-02-133 clinical utilization and outcomes of rhythm control therapy for atrial fibrillation in a large hospital system

The best approach towards management of atrial fibrillation (AF) is debated. Although recent trials suggest a role for early rhythm control (RyC), real world data on its clinical impact is lacking. We sought to define the clinical phenotype of patients receiving RyC, along with describing its utilization. We also investigated the impact of RyC (Class 1 or 3 antiarrhythmics (AAD) or catheter ablation (CA)) on mortality and AF hospitalization compared to those receiving no RyC. We analyzed electronic health record and social security death index data for adult patients with AF and no prior RyC (n= 96066) from University of Pittsburgh Medical Center between 1/2010 and 11/2022. Baseline demographics, cardiovascular risk factors, comorbidity burden, and medication use were evaluated. Time to RyC quartiles (Q1 <84 days(d), Q2 84-309d, Q3 309-949d, Q4 >949 d) were compared using Kruskal-Wallis tests. Adjusted Cox proportional hazard models with RyC as a time dependent variable were utilized to assess impact on mortality and future AF hospitalization. 14160 (15%) patients received RyC (amiodarone 6849 (48%), sotalol 2096 (15%), flecainide 1626 (11%), dofetilide 1366 (10%)). CA was used as initial RyC in 1913 (14%) and in a total 3626 (26%). Median (IQR) time to RyC was 309d (865) (ablation: 472d (1134); AAD: 329d (888)). RyC patients were significantly younger (age 68±11.7 vs 73±12.7), male (58% vs 55%), have commercial insurance (36% vs 27%), receive initial care by a cardiologist, and have lower CHA2DS2VASC (2.6 ±1.6 vs 3.2 ±1.6) and comorbidity scores (Elixhauser 2.6 vs 3.6). Early RyC (Q1) patients had significantly more heart failure (18% vs 12%) and higher CHADS2VASC and comorbidity scores than late RyC (Q4) patients. Over a median follow up of 4.0 years (IQR 5.7), 23% RyC vs 33% non-RyC died (figure 1) (Q1 mortality 21% VS Q4 24%). In a multivariate Cox model, earlier use of RyC was associated with lower mortality (HR 0.89, 95% CI 0.85-0.92, p<0.001) and AF hospitalization (HR 0.54; 95% CI 0.52-0.58, p<0.001). In a large contemporary patient cohort, initial RyC was infrequently utilized or used late and predominantly consisted of amiodarone (48%). Earlier use of rhythm control was associated with significantly improved clinical outcomes and warrants more consideration in AF management.