Risk and management of acute kidney injury resulting from hemoglobinuria following pulsed-field ablation in atrial fibrillation

Abstract Background High-voltage pulses can cause hemolysis leading to hemoglobinuria. Purpose We evaluated the prevalence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF). Methods A consecutive series of 128 AF patients undergoing PFA were included in this analysis. The initial patients that did not receive post-ablation hydration were classified as group 1 (n=28) and the rest of the study population that received planned fluid infusion of ≥2 L after the procedure, were categorized as group 2 (n=100). Patients with estimated glomerular filtration rate (eGFR) <45 were excluded. All underwent extensive ablation beyond pulmonary vein isolation. If urine tested positive for hemoglobin, blood samples were tested for Haptoglobin. Results Baseline characteristics of the study population are provided in Table 1. Number of overall PFA applications were comparable between groups (group 1: 52.07±23.99 vs group 2: 59.83±22.78, p=0.149). Four patients in group 1 received 94.63±3.20 PFA applications. In group 2, 4 patients received >90 applications (94±2.82) and 2 patients received >150 (158.5±4.95) PFA applications. Of the 28 in group 1, 21 (75%) developed hemoglobinuria during the 24-hour following catheter ablation. Mean post-ablation S-Cr was significantly higher than the baseline value in these 21 patients (1.46±0.28 vs 0.86±0.24, p <0.001). Of the 21, 4 (19%) patients that received a mean of 94.63±3.20 PFA applications had the S-Cr. >2.5 mg/dL (mean: 2.95±0.21). These 4 patients were also markedly oliguric (<400 ml/day) in the immediate post-ablation period. Group 2 patients received significantly higher amount of fluid infusion following catheter ablation compared to group 1 (2092.53±198.94 vs 487.48±72.74 ml, p<0.001). None of the 100 patients from group 2 developed detectable hemoglobinuria or elevation of S-Cr including the 4 patients with >90 and 2 patients with >150 PFA applications. Mean post-ablation Haptoglobin was 10.00± 8.40 (normal: 36–195 mg/dL). The accuracy of number of applications predicting Haptoglobin decline was excellent with the area-under the curve (AUC) 0.886 ± 0.068 with 95% CI of 0.754 – 1.000. (P-value = 0.002). In multivariable analysis, both hydration (R-square 0.34, p <0.01) and number of PFA applications (R-square 0.40, p <0.038) were independent predictors of post-procedure acute kidney injury. Conclusions Based on our findings, number of PFA applications was an independent predictor of renal insult in patients receiving extensive ablation that could be prevented using planned fluid infusion immediately after the procedure.