Improvement in renal function following cryoballoon ablation for atrial fibrillation

Purpose: Patients with chronic kidney disease are predisposed to heart rhythm disorders including atrial fibrillation (AF). Several studies have suggested that radiofrequency catheter ablation of AF improves renal function. However, little data exists for pulmonary vein isolation with cryoballoon ablation (CBA). The purpose of this study is to assess change in renal function following CBA for AF. Method: This is a single-center retrospective study that included patients who underwent CBA for AF between 2011 and 2016. Patients were grouped by baseline-estimated glomerular filtration rate (eGFR): ≥ 90 (Stage G1), 60–89.9 (Stage G2), and 30–59.9 mL/min/1.73 m² (Stage G3). Change in eGFR was assessed > 3 months post-ablation. Results: A total of 306 patients with both pre- and post-ablation serum creatinine measurements available were included. Baseline eGFRs for Stages G1, G2, and G3 patients were 103.5 ± 12.9 (n = 82), 74.7 ± 8.2 (n = 184), and 52.6 ± 6.6 mL/min/1.73 m² (n = 40), respectively. Renal function was assessed 310.8 ± 104.2 days post-ablation. Average intra-procedural contrast use was 58.4 ± 23.8 mL. There was no significant change in eGFR following CBA in Stage G1 patients (p = 0.10). For those with Stages G2 and G3 renal function, eGFR improved by 6.1% (4.2 mL/min/1.73 m², p < 0.01) and 13.8% (7.2 mL/min/1.73 m², p < 0.01), respectively. This improvement was seen regardless of the presence or absence of recurrent atrial arrhythmias. Conclusions: CBA for AF may be associated with an improvement in renal function, particularly among those with a reduced baseline eGFR despite recurrence of atrial arrhythmias and intra-procedural contrast use.