Abstract
BACKGROUND: Atrial fibrillation (AF) recurrence after catheter ablation remains a clinical challenge despite guideline-recommended efficacy. Emerging evidence implicates inflammatory biomarkers in predicting arrhythmia recurrence. This study investigated the novel CALLY index, a composite inflammatory marker, as a prognostic indicator for postablation AF recurrence. METHODS: In this prospective cohort study, 556 consecutive AF patients undergoing catheter ablation (June 2018-June 2023) were stratified into recurrence and sinus rhythm (SR) maintenance groups. Cox regression and Kaplan-Meier analyses evaluated associations between the CALLY index and recurrence risk. Predictive accuracy was assessed via receiver operating characteristic (ROC) curves and area under the curve (AUC). RESULTS: Over a median 12-month follow-up, 102 patients (18.3%) experienced recurrence. The SR group exhibited significantly higher CALLY indices than the recurrence group (3.24 ± 1.68 vs. 1.89 ± 0.57; p < 0.001). Univariate Cox regression identified the CALLY index as inversely associated with recurrence (HR: 0.439, 95% CI: 0.292-0.659; p < 0.001), with persistence after multivariable adjustment (HR: 0.887, 95% CI: 0.789-0.956; p = 0.031). Tertile-based stratification revealed a 29% lower recurrence risk in the high-CALLY group versus the low-CALLY group (HR: 0.71, 95% CI: 0.68-0.76; p = 0.017). ROC analysis demonstrated optimal discrimination at a CALLY threshold ≥ 1.433 (AUC: 0.7899; sensitivity: 76.4%; specificity: 74.8%; p < 0.001). CONCLUSION: The CALLY index independently predicts AF recurrence postablation, offering potential utility in risk stratification. These findings support its integration into clinical decision-making to optimize post-procedural management.