A Comprehensive Assessment of Renal Function During and After Pulsed Field Ablation

BACKGROUND: Acute kidney injury is an uncommon complication of pulsed field ablation (PFA). There is, however, limited empirical data on the dynamics of renal biomarkers apart from creatinine. Furthermore, no study to date has assessed creatinine at more than 24 h after the procedure. METHODS: Patients undergoing PFA for atrial fibrillation (AF) were enrolled in a prospective observational study. The ablation was performed using the Farawave pentaspline catheter along with the Farapulse system and consisted of pulmonary vein isolation along with additive lesions in patients with persistent AF and/or atrial flutter. Administration of 500-1000 mL of crystalloid was a mandatory part of the periprocedural management protocol. Before and 24 h after the procedure, serum renal biomarkers were measured (urea, creatinine, cystatin C, NGAL, and KIM-1), and urinalysis was performed. Hemolysis indices (haptoglobin, Lactate Dehydrogenase, and red blood cell microparticles) were measured after the procedure. Patients were instructed to undergo blood sampling for creatinine and urea 48 h after the procedure. RESULTS: Samples from 88 patients were analyzed (mean age 67 ± 8.8 years, 33% female, 53% paroxysmal AF, average of 63 [IQR: 40-77] applied pulses). The creatinine concentration at 24 h decreased from 86 (IQR: 72-100) to 82 (IQR: 68-92) µmol/L (p < 0.001), the concentration at 48 h was similar to preprocedural values (83 [IQR: 69-100] µmol/L; (p = 1.00). However, 9 patients (10.2%) met AKI criteria; in six of them, AKI was only detectable at the 48-h measurement. Serum cystatin-C levels remained unchanged, and urea and urinary erythrocytes increase significantly from baseline to 24 h. NGAL levels increased significantly from 121 (IQR: 86-173) to 143 (IQR: 112-198) at 24 h while changes in KIM-1 were unsignificant. All changes in renal function were transient and did not require hospitalization. Logistic regression identified age and the total number of pulsed field pulses as the major risk factors for AKI. CONCLUSIONS: Routine PFA with periprocedural hydration and an average of 63 PF pulses appears safe in patients without significant preexisting renal disease, with a low risk of clinically relevant renal impairment. However, the incidence of AKI in our cohort was higher than previously reported, suggesting that transient kidney function changes may be more common than recognized. These findings highlight the need for kidney function monitoring beyond 24 h in higher-risk patients undergoing PFA.