Epicardial adipose tissue index combined with endothelial activation and stress index predicts atrial fibrillation recurrence following radiofrequency catheter ablation: a real-world study

Atrial fibrillation (AF) recurrence after radiofrequency catheter ablation (RFCA) remains a significant clinical challenge. We aimed to evaluate whether combined markers capturing both local substrate derangement and systemic endothelial stress can outperform conventional predictors for AF recurrence. This study retrospectively enrolled 765 patients with atrial fibrillation (paroxysmal and persistent) who underwent radiofrequency ablation at the First Affiliated Hospital of Anhui Medical University from October 2022 to August 2024. Epicardial adipose tissue index (EAT Index = EAT volume/body surface area) was derived from cardiac CT, and the endothelial activation and stress index (EASIX = LDH × creatinine/platelets) was calculated from routine blood tests. Restricted cubic splines revealed an approximately linear dose–response relationship between EAT Index and recurrence risk (Poverall < 0.001; Pnonlinearity = 0.952, indicating no evidence of nonlinearity). In fully adjusted Cox models, each 10 mL/m2 increase in EAT Index carried a hazard ratio (HR) of 1.92 (95% CI 1.61–2.29), while each unit increase in Ln(EASIX score) conferred an HR of 4.81 (95% CI 2.84–8.16). The combined model achieved an area under the curve of 0.753, with a positive predictive value (PPV) of 28.7% and a negative predictive value (NPV) of 93.7%, surpassing either marker alone. In exploratory analyses, Kaplan–Meier analysis showed clear separation among four risk strata (log-rank P < 0.0001), with the high-EAT Index/high-EASIX group exhibiting a 33.3% recurrence rate versus 4.3% in the low-EAT Index/low-EASIX group. Decision curve analysis suggested potential net clinical benefit across a broad range of threshold probabilities. Subgroup analyses demonstrated consistent predictive performance without significant interaction. Integrating EAT Index with EASIX may improve recurrence risk stratification after AF ablation, though external validation is needed.