RESUMO
BACKGROUND: No previous study has assessed the role of renal impairment in predicting the long-term risk of atrial fibrillation recurrence after cardioversion. METHODS: One hundred and fifty-nine consecutive patients with persistent atrial fibrillation undergoing successful cardioversion were enrolled. Renal function was assessed based on the estimated glomerular filtration rate (eGFR) at baseline and during follow-up. Patients were prospectively followed up for eGFR and recurrence of atrial fibrillation up to 1 year. RESULTS: Patients were divided into 4 groups based upon their eGFR (group 1 >90 mL/min: 33 patients, group 2: 60-90 mL/min: 55 patients, group 3: 30-59 mL/min: 53 patients, group 4: <30 mL/min: 18 patients). Overall, 101 out of 159 (64%) patients experienced atrial fibrillation recurrence within 1 year follow-up. Atrial fibrillation recurrence was independently associated with the level of reduction of eGFR at baseline (eGFR < 30 mL/min: hazard ratio [HR] 6.82, P < 0.001; eGFR 30-59 mL/min: HR 3.31, P = 0.01; eGFR 60-90 mL/min: HR 2.10, P = 0.13; eGFR > 90 mL/min reference group). In patients with maintained sinus rhythm after 12-month follow-up eGFR was increased (8.46 ± 9.49 mL/min [range -7 to 43]), whereas patients with atrial fibrillation recurrence showed a decrease in eGFR over time (-5.75 ± 9.4 [range -32 to 25], P < 0.001). CONCLUSION: Among a group of patients with persistent atrial fibrillation undergoing successful cardioversion, impaired renal function (based on estimated GFR) was associated with an increased risk of atrial fibrillation recurrence. Maintenance of sinus rhythm was associated with improvement in eGFR in patients with mild or moderate renal insufficiency.