Abstract 4373363: Impact of Rate vs Rhythm Control on Morbidity and Mortality Among Patients with Durable Left Ventricular Assist Devices and New-Onset Atrial Fibrillation: A Propensity-Matched Real-World Cohort Study

Background: The utilization of left ventricular assist devices (LVADs) for both destination therapy and as a bridge to transplantation has become increasingly prevalent in the management of advanced heart failure. Atrial fibrillation (AF), the most common arrhythmia in this population, poses significant management challenges. However, evidence regarding optimal atrial fibrillation (AF) management in left ventricular assist device (LVAD) recipients remains limited and often conflicting. Objective: To compare the impact of rhythm versus rate control strategies on clinical outcomes in patients with durable LVADs who develop new-onset AF. Methods: We conducted a retrospective cohort study using the TriNetX research network, which aggregates electronic health records from over 100 million patients. Adult patients (≥18 years) with advanced heart failure who received an LVAD between January 2015 and May 2025 and subsequently developed new-onset AF were identified. Two cohorts were constructed: those managed with rhythm control (antiarrhythmic drugs or catheter ablation) and those managed with rate control alone. A 1:1 propensity score matching was performed to adjust for demographics and comorbidities. Outcomes were assessed using Kaplan-Meier survival analysis and Cox proportional hazards models, with a follow-up period of one year. Primary outcomes included all-cause mortality, all-cause hospitalizations, and incidence of ischemic stroke. Results: After matching, 3,297 patients in the rate control group were compared with 3,281 patients in the rhythm control group. The matched cohort had a mean age of 71.0 ± 12.8 years, was predominantly male (65%), and primarily Caucasian (68%). Rate control was associated with significantly lower all-cause mortality (HR: 0.64; 95% CI: 0.448–0.918; P = 0.01) and reduced all-cause hospitalization (HR: 0.87; 95% CI: 0.804–0.936; P <0.001). There was no statistically significant difference in the incidence of ischemic stroke (HR: 1.13; 95% CI: 0.697–1.855; P =0.60). Conclusion: In this large, real-world, propensity-matched cohort study, a rate control strategy was associated with lower mortality and hospitalization rates compared to rhythm control in patients with durable LVADs and new-onset AF. These findings suggest rate control may be the safer initial approach in this population. Prospective randomized studies are warranted to validate these findings and guide clinical decision-making.