Phrenic Nerve Injury After Catheter Ablation for Atrial Fibrillation

BACKGROUND: Phrenic nerve injury (PNI) remains a clinically relevant complication of atrial fibrillation (AF) ablation, and contemporary device-specific risk and recovery data are limited. OBJECTIVE: We analyzed a large multicenter database to compare PNI incidence across device platforms. METHODS: This prospective observational study consisted of 19,764 consecutive AF ablations at 20 centers between January 2022 and November 2025. PNI was defined as elevation of the right hemidiaphragm on the next-day post-procedural chest X-ray. RESULTS: PNI occurred in 202 patients; 24 were attributed to radiofrequency ablation (RFA) and 178 to non-RFA during right superior or inferior pulmonary vein (RSPV/RIPV) isolation (Arctic Front Advance [AFA] 43, POLARx 62, POLARx FIT 69, laser balloon 1, hot balloon 2, and pulsed field ablation (1). Cryoballoon-related PNI incidence differed by platform (AFA 1.7% vs. POLARx 4.1% versus POLARx FIT 4.2%; overall P<0.001), with Holm-adjusted differences for AFA versus POLARx/POLARx FIT (both P<0.001). In the cryoballoon cohort, younger age (odds ratio [OR] 0.98), female sex (OR 1.94), lower body mass index (BMI) (OR 0.94), deep sedation/general anesthesia (OR 2.0, vs. light sedation), and POLARx/POLARx FIT use (OR 2.43/2.72, vs. AFA) were independently associated with PNI. Overall recovery was observed in 187/202 (92.6%). Recovery curves differed by presumed injury site (p = 0.006), with faster recovery for RSPV- (vs. RIPV-related PNI); RFA-related PNI during superior vena cava/right atrial ablation tended to recover more slowly. CONCLUSION: The cryoballoon platform was associated with PNI risk, while most PNIs recovered; recovery time course varied by presumed injury site and BMI.