Glomerular filtration rate: A prognostic marker in atrial fibrillation—A subanalysis of the AntiThrombotic Agents Atrial Fibrillation

Objective An increased cardiovascular mortality and morbidity has been widely reported in patients with atrial fibrillation (AF). In this study, a subanalysis of the AntiThrombotic Agents Atrial Fibrillation (ATA‐AF) is performed with the aim to evaluate estimated glomerular filtration rate (eGFR) as an independent prognostic marker of cardiovascular mortality and morbidity in patients with AF. Methods and Results The ATA‐AF study enrolled 7148 patients with AF, in 360 Italian centers. The eGFR was calculated from data reported in patient notes or hospital database. This post‐hoc analysis included 1097 AF patients with eGFR data available and 1‐year clinical follow‐up. The endpoint was assessed as cardiovascular mortality and/or hospital admission for cardiovascular causes at follow‐up. Patients were also divided in two groups according to the eGFR (<60 and ≥60 mL/min/1.73 m2). The Kaplan‐Meyer curve for the mentioned endpoint showed a higher endpoint incidence in the group of patient with eGFR below 60 mL/min/1.73 m2 (P < 0.001). Using multivariate analysis (Cox regression), a trend toward a higher rate of occurrence of the primary endpoint was observed for eGFR below 60 mL/min/1.73 m2 without reaching the conventional level of statistical significance (hazard ratio [HR] 1.40; 95% confidence interval [CI] 0.99‐1.99; P = 0.0572). When eGFR was included in the analysis as continuous variable a significant correlation was observed with the combined endpoint at the Cox regression (HR 0.99, 95% CI 0.98‐0.99, P = 0.04). Conclusion The result of this post‐hoc analysis indicates that an impaired eGFR is independently associated with worse prognosis among patients with AF.