NEMESIS-PFA: Investigating Collateral Tissue Injury Associated With Pulsed Field Ablation

Early evidence showed reduced complications with pulsed field ablation (PFA), but non-target tissue collateral damage created by electroporation effects is poorly understood and may significantly differ between systems.

In this study, the authors evaluated the collateral effects of PFA.

NEMESIS-PFA is a multicenter, observational registry of patients who underwent AF ablation from March 2024 onwards with any approved PFA systems-either a circular multielectrode array, spherical, pentaspline, or variable loop catheter-or radiofrequency ablation (RFA). We assessed procedural characteristics, biomarkers for myocardial injury, hemolytic anemia, and renal function, and left atrial function in select patients.

A total of 871 patients, aged 68.9 ± 10.9 years and male (70.8%), with paroxysmal atrial fibrillation (59.4%), and CHA₂DS₂VASC of 3.3 ± 1.3 were included. Of these, 87.1% (n = 773) underwent PFA with a pentaspline (70.9%), circular multielectrode (14.1%), spherical (12.4%), and variable loop (2.3%) catheter. Significant postprocedural change in certain biomarkers such as troponin (13,551.0 vs 127.5 ng/dL; P < 0.001), lactate dehydrogenase (107.5 vs 26.5 IU/L; P < 0.001), and haptoglobin (-102.0 vs -33.5 mg/dL; P < 0.001) were detected following the PFA procedures compared with RFA, and the change was dose-dependent. There were also significant differences in biomarkers across PFA systems. Lastly, there was a significant change in left atrial ejection fraction (-20.0% vs. -5.0%, P < 0.001) in PFA vs RFA.

Current PFA technologies are associated with worse troponin leak, hemolysis, and renal dysfunction than RFA. As PFA becomes mainstream, future studies appraising these effects and understanding the short term and long-term implications are needed.