Abstract 19180: Early Rhythm Control is Associated With Improved Outcomes in Hypertrophic Cardiomyopathy Patients With Atrial Fibrillation

Abstract

Background: Atrial fibrillation in hypertrophic cardiomyopathy (HCM) patients is associated with worse outcomes with regards to stroke, heart failure hospitalization and death. Contemporary data on Rhythm control (RyC) strategies and outcomes in HCM patients is limited. Objectives: We aimed to assess the clinical characteristics of HCM patients with AF receiving RyC (antiarrhythmic drug and/or catheter ablation) vs no rhythm control (NRC) and compare clinical outcomes between the two groups. Methods: We analyzed the electronic health records of the University of Pittsburgh Medical Center, a large multi-hospital system, between 2010 and 2022. Differences between baseline demographics, cardiovascular risk factors, and comorbidity burden were evaluated with t tests. Adjusted Cox proportional hazards and Kaplan-Meier analyses were performed to evaluate associations between use of rhythm control and all-cause age-adjusted mortality. Results: A total of 552 patients with HCM and AF were analyzed, of which 118 received RyC and 434 NRC. The RyC group was relatively younger (age 64 vs 70), received initial evaluation by a cardiologist (70% vs 57%), had lower CHA2DS2VASC scores (mean 2.5 vs 3.1) and fewer comorbidities (mean Elixhauser scores 3.0 vs 4.7). There were no significant differences in either ejection fraction or left atrial diameter between the groups. Among RyC patients, 38 received catheter ablation and 80 received antiarrhythmic drug as the initial RyC strategy. Over a median follow up of 2.9 years (IQR 0.96-6.0), use of RyC was associated with decreased mortality after adjustment for age, Elixhauser score, and CHA2DS2VASC score (HR 0.54, 95% CI 0.30-0.95, p<0.05, figure 1). Conclusion: Rhythm control in HCM and AF patients is associated with better outcomes as suggested by decreased overall mortality. Prospective studies are needed to establish the best RyC strategy in this cohort.