Pulsed Field Versus Cryoballoon Ablation for Atrial Fibrillation: Procedural Outcomes and Hemolysis-Related Laboratory Changes in a Single-Center Pilot Study

Background and Objectives: Pulsed field ablation (PFA) and cryoballoon ablation (CRYO) are established approaches for pulmonary vein isolation in atrial fibrillation (AF). Given emerging concerns regarding hemolysis following PFA, this pilot study aims to directly compare outcomes between these modalities. This study aims to evaluate differences in laboratory parameters potentially compatible with hemolysis and procedural safety between PFA and CRYO among AF patients. Materials and Methods: In this retrospective single-center analysis, 33 symptomatic AF patients underwent either PFA (n = 17) or CRYO (n = 16). Hemoglobin, hematocrit, platelet count, total bilirubin and renal function were measured at all three pre-specified time points: baseline, immediately after ablation and on day 1. Group × time interactions were tested with linear mixed-effects models, and changes are reported with 95% confidence intervals (CIs). Acute kidney injury (AKI) was defined by KDIGO serum creatinine criteria and assessed individually; sensitivity analyses were restricted to pulmonary-vein-isolation (PVI)-only procedures. Additionally, procedural metrics and complication frequencies were analyzed between groups. Results: The baseline demographics and clinical characteristics did not differ significantly between both groups. Both ablation techniques led to substantial reductions in hemoglobin following the procedure, with no between-group difference (day-1 change −1.84 vs. −1.57 g/dL; difference −0.27, 95% CI −1.01 to +0.47; group × time p = 0.192). Notably, total bilirubin increased to a greater extent with PFA (day-1 change +0.48 vs. +0.15 mg/dL; difference +0.33, 95% CI +0.06 to +0.59; group × time p = 0.003), with the largest separation immediately after ablation (1.43 ± 0.36 vs. 0.99 ± 0.35 mg/dL, p = 0.001). No patient in either group met KDIGO criteria for AKI of any stage; the largest post-procedural rise in creatinine was +0.10 mg/dL in both groups. Conclusions: Both PFA and CRYO caused acute declines in hemoglobin, and total bilirubin rose more after PFA, with no accompanying change in renal function. Further studies involving larger cohorts and direct hemolysis biomarkers are necessary to corroborate these findings.