Renal dysfunction drives recurrence and modifies safety after atrial fibrillation ablation: a contemporary retrospective analysis of CKD stage and energy source interaction

Background Chronic kidney disease promotes systemic inflammation, neurohormonal activation, and atrial fibrosis, potentially increasing arrhythmia recurrence after atrial fibrillation ablation. Although contemporary ablation energy modalities may influence procedural safety, the interaction between renal dysfunction, energy source, and long-term rhythm outcomes remains insufficiently defined in contemporary practice. Purpose To determine whether baseline renal dysfunction independently predicts arrhythmia recurrence and procedural complications after atrial fibrillation ablation, and to evaluate its interaction with ablation energy modality. Methods We performed a retrospective cohort study of consecutive atrial fibrillation ablations between January 2024 and December 2025. Patients were stratified by KDIGO eGFR stage. The primary endpoint was 1-year arrhythmia recurrence following a 3-month blanking period. Secondary endpoints included acute kidney injury (AKI), major bleeding, and 30-day hospitalization. Multivariable Cox regression and Fine–Gray competing risk models were applied. Interaction testing between CKD stage and ablation energy modality was prespecified. Results Among 428 patients, 40% had renal dysfunction (eGFR <60 mL/min/1.73m²). One-year recurrence occurred in 29%, increasing stepwise across KDIGO stages: 20.9% (≥60), 36.6% (30–59), and 53.6% (<30) (log-rank p<0.001). In adjusted Cox analysis, each 10 mL/min/1.73m² decrease in eGFR independently predicted recurrence (HR 1.17, 95% CI 1.09–1.25, p<0.001). eGFR <45 conferred nearly twofold higher risk (HR 1.94, 95% CI 1.42–2.66, p<0.001). Hemoglobin was not independently associated (HR 1.05, 95% CI 0.97–1.14, p=0.18). Addition of eGFR improved model discrimination (C-statistic 0.65 to 0.73, p=0.02). No significant interaction was observed between CKD stage and energy modality for recurrence (p-interaction=0.76). Among patients with eGFR <60, AKI occurred more frequently with radiofrequency versus pulsed electric field energy (9.4% vs 2.8%; adjusted OR 3.21, 95% CI 1.28–8.06, p=0.013). Renal dysfunction independently predicted major bleeding (subdistribution HR 1.79, 95% CI 1.22–2.62, p=0.004) and 30-day hospitalization (HR 1.58, 95% CI 1.19–2.09, p=0.002). Conclusion Baseline renal dysfunction independently predicts arrhythmia recurrence, bleeding, AKI, and early hospitalization after atrial fibrillation ablation. While pulsed electric field energy reduces renal procedural injury, it does not attenuate recurrence risk in advanced CKD, supporting renal function as a key substrate-driven risk stratification marker beyond traditional hematologic parameters.