Variable-Loop Circular vs. Pentaspline Catheter: Hemolysis Outcomes in Pulsed-Field Ablation Procedures for Atrial Fibrillation

Purpose To compare the extent of intravascular hemolysis, quantified by red blood cell microparticles (RBCµs), between patients undergoing pulsed-field ablation (PFA) for atrial fibrillation (AF) with a variable-loop circular catheter (VLCC) and those treated with a pentaspline catheter (PSC). Methods This prospective, single-center observational study included three cohorts of patients undergoing first-time AF ablation: (1) pulmonary vein isolation (PVI) by the PSC (PSC PVI), (2) PVI plus posterior wall and/or mitral isthmus by the PSC (PSC PVI+), and (3) PVI plus posterior wall by the VLCC (VLCC PVI+). Blood samples were collected at baseline, immediately post-ablation, and 24 hours after the procedure to measure RBCµs and other biochemical markers. Results The study included 77 patients (64.2 ± 9.5 years, 42.9% female): 22, 25 and 30 in the PSC PVI, PSC PVI+, and VLCC PVI + groups, respectively. All groups exhibited a significant transient rise in RBCµs concentration immediately after ablation (p < 0.001), returning to baseline within 24 hours. Peak RBCµs levels were highest in the PSC PVI + group, followed by PSC PVI and VLCC PVI+ (all pairwise comparisons p < 0.001). The total number of applications was highest in the PS PVI + group and lowest in the VLCC PVI + group, correlating with the magnitude of hemolysis. Conclusions The VLCC used in persistent AF ablation was linked to lower levels of intravascular hemolysis compared to the PS catheter employed in cases of paroxysmal and persistent AF.