Improvement in Estimated Glomerular Filtration Rate in Patients with Chronic Kidney Disease Undergoing Catheter Ablation for Atrial Fibrillation

INTRODUCTION: Chronic kidney disease (CKD) and atrial fibrillation (AF) often coexist. We studied the association of CKD with atrial fibrosis and the effect of AF ablation on kidney function. METHODS: AF patients who had a pre- and postablation serum creatinine and who completed a late gadolinium enhancement cardiac magnetic resonance imaging (MRI; LGE-MRI) prior to ablation were included. Estimated glomerular filtration rate (eGFR) was calculated and CKD was staged using the National Kidney Foundation guidelines. Patients with eGFR <30 mL/min/1.73 m(2) were excluded. LGE-MRI was used to quantify atrial fibrosis. Patients were followed for recurrence and change in eGFR. RESULTS: A total of 392 patients were included in the study. A total of 118 (30.2%) had CKD stage 1, 198 (50.4%) CKD stage 2, 56 (14.3%) CKD stage 3A, and 20 (5.1%) CKD stage 3B. Patients with advanced CKD were more likely to be male and to have cardiovascular disease. Atrial fibrosis was not significant different between included CKD stages: 15.8 ± 8.8%, 16.6 ± 12.1%, 17.1 ± 10.4%, and 16.5 ± 8.4% for CKD stage 1, 2, 3A, and 3B, respectively (P = 0.476). At a median of 115 days following ablation, eGFR increased significantly in CKD stage 2 (74 ± 9 to 80 ± 23; P = 0.04), 3A (53 ± 5 to 69 ± 24; P < 0.001), and 3B (40 ± 4 to 71 ± 28; P < 0.01) and decreased in CKD stage 1 (109 ± 18 to 82 ± 28; P < 0.001). Arrhythmia recurrence was associated with atrial fibrosis (hazard ratio [HR] = 1.04, P < 0.01) and persistent AF (HR = 1.5; P = 0.04) but not with CKD stage (HR = 0.98; P = 0.89). CONCLUSIONS: Restoring sinus rhythm with ablation leads to significant improvement of renal function in patients with chronic kidney disease.