C-Reactive Protein–Albumin–Lymphocyte (CALLY) Index as an Independent Risk Factor for Postoperative Atrial Fibrillation Recurrence

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.