Effect of pulsed field ablation delivered from noncontact catheter electrodes on hemolysis: A tissue proximity...

Pulsed field ablation (PFA) for atrial fibrillation can induce hemolysis, particularly when pulsed field (PF) energy is delivered from catheter electrodes that are not in contact with myocardial tissue. The variable-loop circular catheter (VLCC) incorporates tissue proximity indication (TPI) software to identify catheter-tissue contact. Whether PFA applications delivered from TPI-negative (noncontact) VLCC electrodes contribute to hemolysis remains unclear.

The purpose of this study was to determine whether PFA delivered from TPI-negative VLCC electrodes is associated with postprocedural hemolysis.

We retrospectively analyzed 20 consecutive patients who underwent their first PFA using the VLCC and CARTO 3 system (Biosense Webster Inc.). For each 3-pulse application set, catheter-tissue contact was assessed using TPI. We counted the cumulative number of VLCC electrode uses delivering PF energy; among these, those that were TPI-negative were summed and defined as the cumulative number of TPI-negative electrode uses (nTPI-EU). Postoperative lactate dehydrogenase (LDH), total bilirubin (T-Bil), and the postoperative-to-preoperative haptoglobin ratio served as hemolysis markers.

A mean of 78.3 ± 20.0 PFA applications (772.9 ± 204.1 VLCC electrode uses) were delivered per patient; the mean nTPI-EU was 438.8 ± 238.1. Compared with preoperative values, postoperative LDH and T-Bil increased significantly whereas haptoglobin decreased (P < .01 for all). nTPI-EU correlated positively with LDH (r = 0.663; P < .01) and T-Bil (r = 0.736; P < .01) and negatively with the postoperative-to-preoperative haptoglobin ratio (r = -0.556; P = .01).

The cumulative number of noncontact catheter electrodes delivering PF energy was associated with hemolysis. Strategies that minimize the number of noncontact catheter electrodes, in addition to limiting total PFA applications, may reduce the risk of hemolysis.