Comparison of hemolysis induced by different pulsed-field ablation systems

Pulsed-Field Ablation (PFA) is an innovative ablation technology, which, as a side effect, causes dose-dependent hemolysis. Currently, three PFA systems are commercially available in Europe: A pentaspline catheter, a lattice-tip focal catheter, and a variable loop circular catheter.

All previous Studies investigating hemolysis during PFA have utilized a pentaspline catheter system. We aimed to provide the first retrospective comparison of hemolysis levels among all currently available PFA systems, and to examine dose-dependency across these different platforms.

From our prospective atrial fibrillation ablation registry, we included all patients treated with the lattice-tip focal (n=18) or variable loop circular (n=27) catheter. Additionally, we randomly included thirty patients treated with the pentaspline catheter within the same time period. Demographic and procedural data were obtained through chart review. For each procedure, we recorded the number of PFA applications. Routine measurements of creatinine and hemolysis markers were taken before and one day after the ablation procedure. For statistical evaluation, we applied Fisher’s exact test, the Kruskal-Wallis rank sum test, or the pairwise Wilcoxon test, as appropriate.

The median age of the 75 included patients was 69 years, with 34 (25%) being women. The median number of applications was 46 for the lattice-tip focal catheter, 36 for the pentaspline catheter, and 21 for the variable loop circular catheter. Baseline levels of creatinine and hemolysis markers were similar across groups. The overall decrease in haptoglobin levels was more pronounced in cases treated with the pentaspline and variable loop circular catheter compared to the lattice-tip focal catheter (-0.68 ± 0.37 g/l, -0.60 ± 0.29 g/l, -0.23 ± 0.21 g/l, respectively; p < 0.0005; Figure and Table). The decrease in haptoglobin per application was different between the groups (-16.9 ± 8.5 mg/l, -28.1 ± 13.6 mg/l, -6.4 ± 8.7 mg/l, respectively; p < 0.0001; Figure and Table). The increase in LDH followed the same pattern (70.0 ± 65.8, 40.3 ± 64.1, 25.6 ± 36.3, respectively; p < 0.05; Table). No hemolysis-related complications occurred, and creatinine levels remained unchanged post-procedure compared to pre-procedure.

The extent of hemolysis induced by PFA procedures and per PFA application varies across different PFA platforms. Focal PFA catheters cause less hemolysis per procedure and per application than large-footprint PFA catheters.