R2(GFR)CHADS2 and R2(GFR)CHA2DS2VASc schemes improved the performance of CHADS2 and CHA2DS2VASc scores in death risk stratification of Chinese older patients with atrial fibrillation

Background: This analysis was carried out to refine the CHADS 2 and CHA 2 DS 2 VASc scores by combining creatinine clearance (CrCl) and glomerular filtration rate (GFR) and evaluate the performance of CrCl-based and GFR-based schemes in death risk stratification of Chinese older patients with atrial fibrillation (AF). Methods: There were 219 older patients with AF, and all-cause mortality was assessed during the follow-up of 1.11 years. Renal function was evaluated using the CrCl formula and different GFR (Modification of Diet in Renal Disease [MDRD], Chinese MDRD [CMDRD], Mayo Clinic Quadratic [Mayo] and Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) formulas, and five kinds of R 2 CHADS 2 and R 2 CHA 2 DS 2 VASc schemes were generated by combining CrCl and GFR with CHADS 2 and CHA 2 DS 2 VASc scores. Results: In Cox regression multivariate analysis, CrCl <60 mL/min was moderately associated with death risk ( P =0.122 and P =0.144). When MDRD, CMDRD, CKD-EPI and Mayo formulas were used to ascertain the GFR, GFR <60 mL/min/1.73 m 2 was significantly associated with death risk ( P <0.001 for all). In the models with CHADS 2 and CHA 2 DS 2 VASc scores as the linear covariates, CrCl and GFR as the continuous variables were significantly associated with death risk ( P <0.05 for all). C-statistics of CrCl-based schemes – R 2(CrCl) CHADS 2 and R 2(CrCl) CHA 2 DS 2 VASc – moderately exceeded that of CHADS 2 and CHA 2 DS 2 VASc scores ( P =0.081 and 0.082). C-statistics of GFR-based schemes – R 2(GFR) CHADS 2 and R 2(GFR) CHA 2 DS 2 VASc – significantly exceeded that of CHADS 2 and CHA 2 DS 2 VASc scores ( P <0.05 for all). Conclusion: Chinese older patients with AF with lower levels of GFR and GFR <60 mL/min/1.73 m 2 had a significantly high death risk, and those with lower levels of CrCl or CrCl <60 mL/min had a significantly or modestly high death risk. There was significantly better performance of GFR-based schemes and moderately better performance of CrCl-based schemes in death risk stratification compared with CHADS 2 and CHA 2 DS 2 VASc scores.