Abstract Body (Do not enter title and authors here): Introduction: Contemporary trial data and professional guidelines support a rhythm control strategy with catheter ablation for patients with comorbid atrial fibrillation (AF) and heart failure (HF). However, the penetrance of these specialized and expensive interventions by race, ethnicity, and socioeconomic status has not been well described.

Research Question: We sought to examine how race/ethnicity may be associated with rates of catheter ablation among patients with AF and HF.

Methods: Using the Epic Cosmos database, which provides nationally-representative data by combining electronic health record data from over 1,500 electronic health record systems, we examined trends in catheter ablation over time stratified by race and ethnicity. Patients were identified if they had at least two encounters between 2015 and 2024 with ICD-10 codes for each of AF and HF. We used social vulnerability index (SVI), a geographically defined measure in which higher SVI indicates more social vulnerability, as a proxy for socioeconomic status. The primary outcome of interest was catheter ablation for atrial fibrillation, identified by CPT code. Patients were followed until the outcome of interest or 12/31/2024, whichever was earlier.

Results: Among 2,646,219 patients with comorbid AF and HF, 137,260 (5.2%) underwent catheter ablation during the study period. Ablation rate was greater among non-Hispanic White (NHW) patients (5.5%) than Hispanic (4.7%, p < 0.05) or non-Hispanic Black (NHB) patients (3.5%, p < 0.05). Ablation rates were higher among each race/ethnicity group as social vulnerability decreased (p < 0.05 for trend) (Figure 1). The ablation rate for the most vulnerable NHW patients (5.0%) was numerically higher than that of the least vulnerable NHB patients (4.3%), although this comparison was not statistically significant. The annualized rate of catheter ablation per 100 new AF diagnoses increased faster among NHW patients (1.2% per year) compared to Hispanic (0.8% per year, p < 0.05) or NHB patients (0.7% per year, p < 0.05) (Figure 2).

Conclusion: Our findings suggest a disparity in care utilization by race/ethnicity that is not explained by differences in social vulnerability and appears to be increasing over time. More equitable use of catheter ablation is important to improving outcomes for patients with comorbid AF and HF.