Background
Pulsed field ablation (PFA) is an emerging ablation technology for atrial fibrillation (AF) and other forms of arrhythmias. However, it is associated with dose-dependent hemolysis. Since variations in catheter configuration could influence the hemolysis intensity, we investigated the impact of different configurations of a pentaspline catheter on various hemolysis markers in both in vitro as well in vivo settings.
Methods
In the in vitro model, PFA applications in flower, basket, and olive configurations were performed in erythrocyte concentrates, followed by measurement of the hemolysis index, free plasma hemoglobin, and lactate dehydrogenase (LDH) levels. In the in vivo study, twenty patients undergoing pulmonary vein isolation with PFA for atrial fibrillation were analyzed. Hemolysis parameters, cardiac biomarkers, and complete blood counts were measured before, immediately after, and on days 1 and 2 following PFA treatment.
Results
In the in vitro experiments, PFA applications in olive configuration induced significantly greater hemolysis in erythrocyte concentrates compared to basket or flower configurations. After 20 applications, the hemolysis index increased by 44 in the olive group, compared with 24 in the flower group and 22.5 in the basket group.
In vivo, all twenty patients underwent successful PFA ablation with the pentaspline catheter. The mean age was 65.1 ± 8.1 years, and 50% were male. Paroxysmal atrial fibrillation was present in 75% of patients. On average, 38.2 ± 2.6 PFA applications were delivered per patient, with a mean procedure duration of 65.2 ± 22.4 minutes.
Following PFA, the hemolysis index increased significantly from 6.7 ± 11.77 before to 24.65 ± 6.28 immediately after treatment (p < 0.0001). Consistently, haptoglobin levels decreased from 1.00 ± 0.37 g/L before to 0.53 ± 0.36 g/L on day 1 (p < 0.001). Additional markers of hemolysis, including free hemoglobin, lactate dehydrogenase (LDH), total bilirubin, and indirect bilirubin, consistently demonstrated evidence of hemolysis following PFA application.
In a sub analysis comparing patients with and without olive configuration applications (n = 10 per group), baseline characteristics were well balanced between both groups. Patients treated with olive applications exhibited a greater decline in haptoglobin (−0.55 g/L vs. −0.38 g/L; p = 0.02), indicating an increased hemolytic effect associated with this configuration.
Conclusion
This study demonstrates, both in vitro and in vivo, that PFA using the pentaspline catheter induces configuration-dependent hemolysis. Among the tested configurations, the olive configuration was associated with higher levels of hemolysis compared with the basket and flower configurations. Evaluating the safety of PFA remains an important area for future research.
