Chronic kidney disease and risks of adverse clinical events in patients with atrial fibrillation

 BACKGROUND  Chronic kidney disease (CKD) is highly prevalent in patients with atrial fibrillation (AF). However, the association between CKD and clinical consequences in AF patients is still under debate.

 METHODS  We included 19,079 nonvalvular AF patients with available estimated glomerular filtration rate (eGFR) values in the Chinese Atrial Fibrillation Registry from 2011 to 2018. Patients were classified into no CKD (eGFR ≥ 90 mL/min per 1.73 m²), mild CKD (60 ≤ eGFR < 90 mL/min per 1.73 m²), moderate CKD (30 ≤ eGFR < 60 mL/min per 1.73 m²), and severe CKD (eGFR < 30 mL/min per 1.73 m²) groups. The risks of thromboembolism, major bleeding, and cardiovascular mortality were estimated with Fine-Gray regression analysis according to CKD status. Cox regression was performed to assess the risk of all-cause mortality associated with CKD.

 RESULTS Over a mean follow-up of 4.1 ± 1.9 years, there were 985 thromboembolic events, 414 major bleeding events, 956 cardiovascular deaths, and 1,786 all-cause deaths. After multivariate adjustment, CKD was not an independent risk factor of thromboembolic events. As compared to patients with no CKD, those with mild CKD, moderate CKD, and severe CKD had a 45%, 47%, and 133% higher risk of major bleeding, respectively. There was a graded increased risk of cardiovascular mortality associated with CKD status compared with no CKD group: adjusted hazard ratio HR was 1.34 (95% CI: 1.07−1.68, P = 0.011) for mild CKD group, 2.17 (95% CI: 1.67−2.81, P < 0.0001) for moderate CKD group, and 2.95 (95% CI: 1.97−4.41, P < 0.0001) for severe CKD group, respectively. Risk of all-cause mortality also increased among patients with moderate or severe CKD.

 CONCLUSIONS CKD status was independently associated with progressively higher risks of major bleeding and mortality, but didn’t seem to be an independent predictor of thromboembolism in AF patients.