Preoperative CALLY Index and Quantitative Left Atrial Low-Voltage Burden are Associated with Documented Recurrence After First Ablation for Persistent Atrial Fibrillation: A Retrospective Cohort Study

Background and Objectives: We assessed whether preoperative C-reactive protein–albumin–lymphocyte (CALLY) index and intraoperative left atrial low-voltage area (LVA) burden provide complementary prognostic information after first ablation for persistent atrial fibrillation. Materials and Methods: This retrospective cohort included 259 patients. The endpoint was first documented atrial fibrillation, flutter, or tachycardia lasting ≥ 30 s after a 60-day blanking period. ln(1/CALLY) and LVA burden were modeled with natural cubic splines in landmark Cox models; diagnostics prompted an extended model allowing LVA effects to vary with log time. Results: There were 114 recurrences. Both exposures showed nonlinear associations (overall P< 0.001; P for nonlinearity=0.011 and 0.004). Relative to the median, the 75th percentile of ln(1/CALLY), where higher values correspond to lower CALLY and a less favorable systemic profile, had HR 1.99 (95% CI 1.47– 2.70). Corresponding LVA HRs were 2.41, 4.78, 7.36, and 10.21 at days 90, 150, 240, and 364, although late high-LVA support was sparse. Harrell C increased from 0.648 to 0.819 after adding both markers. Near-12-month performance was similar across fixed Cox, time-varying Cox, and fixed-horizon logistic models. Conclusion: CALLY and LVA burden provided complementary systemic-host and electroanatomic information. Findings are prognostic within the observed operator-directed pathway and require external validation.