Periprocedural assessment of intravascular hemolysis and renal function during atrial fibrillation ablation using pulse field and cryoablation - preliminary results

Pulmonary vein isolation remains one of the most effective treatment strategies in patients with atrial fibrillation for preventing arrhythmia recurrence. Recent introduction of irreversible electroporation with pulse field ablation (PFA) and its high cardioselective properties lowered the risk of collateral damage during the procedure, such as phrenic nerve palsy, damage to the esophagus or pulmonary veins resulting in their stenosis. However, new potential complications have emerged. Studies have shown that PFA may result in a significant intravascular hemolysis compared to radiofrequency ablation, leading in some cases to an acute kidney injury.

The aim of this study was to compare the periprocedural intravascular hemolysis and renal function parameters in patients undergoing PFA and cryoballoon ablation (CBA) for atrial fibrillation.

Patients with symptomatic atrial fibrillation undergoing PFA and CBA were included in this retrospective analysis. Collection of blood samples was performed at baseline, immediately after the procedure (D0) and on the next day following the procedure (D1). We assessed the concentration of lactate dehydrogenase (LDH), haptoglobin, aspartate aminotransferase (AST), indirect bilirubin and creatinine.

Seventy five patients (age: 68 ± 10 years; 47% women; 46 [61%] paroxysmal atrial fibrillation) were enrolled: 48 patients were in the PFA group (25 in the PVI-only subgroup with 43 ± 4 applications; 23 in the PVI-plus additional lesions subgroup with 70 ± 6 applications) and 27 patients in the CBA group. Compared to baseline, there was a significant change in hemolysis parameters in both groups on D1 (for PFA: indirect bilirubin [0.35 ± 0.17 mg/dl vs 0.72 ± 0.54 mg/dl P< 0.001], AST [30 ± 10 U/l vs 64 ± 23 U/l, P< 0.001], haptoglobin [1.36 ± 0.54 g/l vs 0.58 ± 0.37 g/l, P< 0.001], LDH [221 ± 54 U/l vs 284 ± 59 U/l, P< 0.001]; for CBA: indirect bilirubin [0.34 ± 0.18 mg/dl vs 0.43 ± 0.31 mg/dl P= 0.01], AST [30 ± 13 U/l vs 46 ± 14 U/l, P< 0.001], haptoglobin [1.30 ± 0.75 g/l vs 0.93 ± 0.61 g/l, P< 0.001], LDH [198 ± 46 U/l vs 213 ± 39 U/l, P= 0.02]). The change of all measured hemolysis parameters was significantly greater in the PFA vs CBA group (all P < 0.001). In the PFA group PVI-plus subgroup compared to PVI-only subgroup was associated with a greater decline of haptoglobin (P< 0.001) and increase in AST (P< 0.001) and LDH (P = 0.03) concentration. There was no increase in serum creatinine in either group.

Although pulse field ablation and cryoballoon ablation are both associated with a periprocedural intravascular hemolysis, its degree is significantly higher in PFA than in CBA. No significant renal function decline was observed with either method. Until more data from larger studies is available it is reasonable to minimize the number of PFA lesions during the procedure.