Biomarker response to balloon-in-basket pulsed field ablation: does posterior wall isolation matter?

Background A novel balloon-in-basket pulsed field ablation (BiB-PFA) catheter enables efficient pulmonary vein isolation (PVI) and allows posterior wall isolation (PWI) within the same procedure. The incremental biological effect of PWI compared to PVI alone remains uncertain, particularly regarding inflammation, myocardial injury, and hemolysis. Methods In this prospective, single-center study, consecutive patients with atrial fibrillation underwent first-time BiB-PFA, either PVI only or PVI plus PWI. Venous blood samples were collected before and one day after ablation. Biomarkers included leukocytes, platelets, hemoglobin, C-reactive protein (CRP), haptoglobin, bilirubin, lactate dehydrogenase (LDH), creatinine, estimated glomerular filtration rate (GFR), myoglobin, creatine kinase (CK), and troponin T. Results A total of 60 patients were enrolled (PVI only n=30, PVI+PWI n=30). Baseline characteristics were comparable. PVI+PWI required more applications (19 vs. 16; p<0.001) but had similar procedure time. Both groups showed significant increases in inflammatory (CRP, leukocytes), myocardial (troponin T, CK, LDH, myoglobin), and hemolysis markers (bilirubin, LDH, haptoglobin changes; all p<0.001). However, the magnitude of biomarker release did not differ between PVI only and PVI+PWI: Δ troponin T (1154 vs. 1029 ng/L, p=0.694), Δ CK (217 vs. 197 U/L, p=0.652), Δ CRP (2.7 vs. 3.4 mg/L, p=0.475), Δ bilirubin (2.4 vs. 2.8 µmol/L, p=0.842), Δ creatinine (3.3 vs. 9.0 µmol/L, p=0.085). Conclusion BiB-PFA PVI provokes systemic responses involving inflammation, myocardial injury, and hemolysis. Adjunctive PWI increases application number but does not further increase biomarker release, supporting the biological safety of PWI.