MARKERS OF HAEMOLYSIS AND RENAL TUBULAR INJURY AFTER CATHETER ABLATION FOR ATRIAL FIBRILLATION USING PULSED FIELD AND RADIOFREQUENCY ENERGY

Background: Pulsed field ablation (PFA) represents a novel non-thermal alternative in catheter ablation of atrial fibrillation (AF). However, infrequent cases of acute renal failure secondary to intravascular haemolysis have been described after PFA procedures with a very high number of PF impulses.
Objective: To investigate the impact of ablation energy (PFA vs. radiofrequency ablation (RFA)) on the plasma concentration of cell-free haemoglobin (CFH), neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 (NGAL and KIM-1; markers of tubular injury).
Methods: This was a prospective non-randomized study. In a consecutive cohort of patients who underwent AF ablation (PFA of RFA), blood samples were drawn just before the procedure (Sample 1: CFH, NGAL, and KIM-1), immediately after the procedure (Sample 2: CFH) and one day after the procedure (Sample 3: CFH, NGAL, and KIM-1). 
Results: Among 70 patients enrolled (mean age 64.3 ± 10.3 years, 61 % male), 23 underwent RFA and 47 PFA (mean number of PF impulses 52.85 ± 18.37, range 32-100)). Baseline serum creatinine levels were comparable (91.7 ± 22.1 µmol/L vs. 88.8 ± 22.1 µmol/L P = 0.44). In the PFA cohort, a significant increase in CFH was observed immediately post-ablation with a rapid decline to baseline values one day after the procedure (median 60.6 (interquartile range 121.1) µg/mL vs. 2074.1 (2521.5) µg/mL vs. 94.9 (122.6) µg/mL, P <0.001). No significant peri-procedural increase in CFH was observed in the RFA cohort. Compared to baseline, neither the PFA nor the RFA group showed a significant increase in NGAL or KIM-1 postoperatively.
Conclusions: Compared to RFA, PFA leads to significant peri-procedural haemolysis. However, no increase in markers of renal tubular injury was observed in a cohort in which the total number of PF applications was less than 100.