Early Hemolysis, Myolysis and Renal Stress Following Pentaspline Pulsed Field Versus Radiofrequency Ablation of Atrial Fibrillation

BACKGROUND: Pulsed field ablation (PFA) is an effective alternative to radiofrequency ablation (RFA) for pulmonary vein isolation (PVI) in atrial fibrillation (AF), offering procedural advantages and a favourable safety profile. However, single-shot PFA (ssPFA) has been associated with biochemical evidence of haemolysis and myocardial injury, raising concerns regarding potential renal impairment. METHODS: In this prospective observational study, 40 patients undergoing first-time PVI were analysed (20 RFA and 20 pentaspline ssPFA). Blood samples were obtained pre-procedure and 1, 4 and 24 h post-ablation. Markers of myolysis (myoglobin), haemolysis (haptoglobin and bilirubin), renal function (creatinine, eGFR and Cystatin C) and tubular stress (NGAL and KIM-1) were assessed. Biomarker trajectories were analysed using two-way repeated-measures ANOVA and correlation analyses were performed. RESULTS: Significantly higher postprocedural myoglobin levels, greater reductions in haptoglobin and greater elevations in bilirubin were observed after ssPFA than after RFA (all interaction effects p < 0.001). Changes in renal function and tubular stress biomarkers were modest and largely comparable between modalities. Exploratory correlation analyses demonstrated inverse associations between changes in myoglobin and eGFR, with the strongest correlation observed at 24 h (ρ = -0.55). The association between early myoglobin release and subsequent eGFR changes was confined to the ssPFA cohort. CONCLUSIONS: ssPFA induces substantially greater acute myolysis and haemolysis than RFA following PVI. No patient met serum creatinine-defined criteria of acute kidney injury within the observation period. Myoglobin release was associated with transient renal functional changes and may represent a mechanistically plausible, non-causal marker of early renal stress following ssPFA.