Renal function after catheter ablation of atrial fibrillation.

BACKGROUND Kidney function is a known predictor of cardiovascular morbidity and mortality. Although patients with atrial fibrillation (AF) often have kidney dysfunction, less is known about the association between AF and kidney function. We sought to assess changes in kidney function after catheter ablation of AF. METHODS AND RESULTS Patients who underwent catheter ablation of AF were recruited for the present prospective study. Estimated glomerular filtration rate (eGFR) was evaluated before and 1 year after the ablation. Three hundred eighty-six patients (paroxysmal AF, 135; persistent AF, 106; longstanding persistent AF, 145) were studied. Their baseline eGFR was 68 ± 14 mL · min(-1) · 1.73 m(-2). Sixty-six percent and 26% of patients had eGFR of 60 to 89 and 30 to 59 mL · min(-1) · 1.73 m(-2), respectively. Overall, 278 patients (72%) were arrhythmia free over a 1-year follow-up. In patients free from arrhythmia, eGFR increased 3 months later and was maintained until 1 year, whereas in patients with recurrences, eGFR had decreased over 1 year. Changes in eGFR over 1 year in patients free from arrhythmia differed significantly compared with those with recurrences (3 ± 8 versus -2 ± 8 mL · min(-1) · 1.73 m(-2); P<0.0001). In all quartiles of baseline eGFR, changes in eGFR over 1 year after the ablation were greater in patients free from arrhythmia compared with those with recurrences. CONCLUSION Elimination of AF by catheter ablation was associated with improvement of kidney function over a 1-year follow-up in patients with mild to moderate kidney dysfunction.