Impact of renal function deterioration on adverse events during anticoagulation therapy using non-vitamin K antagonist oral anticoagulants in patients with atrial fibrillation

Renal function is crucial for patients with non-valvular atrial fibrillation (NVAF) using non-vitamin K antagonist oral anticoagulants (NOAC). The incidence of renal function deterioration during anticoagulation therapy and its impact of adverse events are unknown. In 807 consecutive NVAF patients treated with NOAC and with estimated creatinine clearance (eCCr) a parts per thousand yen 50 ml/min (mean age 68 +/- 11 years, mean CHADS(2) score = 1.8 +/- 1.4, CHA(2)DS(2)-VASc score = 2.8 +/- 1.8, HAS-BLED score = 1.7 +/- 1.1), we analyzed the time course of renal function and clinical outcomes, and compared these with the data of general Japanese inhabitants from the Suita Study (n = 2140). Of the 807 patients, 751 (93 %) maintained eCCr a parts per thousand yen 50 ml/min (group A) whereas the remaining 56 (7 %) fell into the eCCr < 50 ml/min (group B) during the 382 +/- 288 days of follow-up. Multivariate logistic regression analysis revealed that advanced age, lower body weight, and congestive heart failure were independent predictors for renal function deterioration in patients with eCCr a parts per thousand yen 50 ml/min at baseline. Major and/or minor bleedings were more commonly observed in group B than in group A (21 vs. 8 %; P = 0.0004). The CHADS(2), CHA(2)DS(2)-VASc, and HAS-BLED scores were also significant predictors of renal function deterioration (P < 0.0001). The incidences of renal function deterioration were 1.4, 3.4, 10.5 and 11.7 % in patients with CHADS(2) score of 0, 1, 2 and a parts per thousand yen3, respectively. As to CHA(2)DS(2)-VASc score, renal function deterioration occurred in 0, 1.7, 9.8 and 15.0 % with a score of 0, 1-2, 3-4 and a parts per thousand yen5, respectively. In the Suita Study of the general population, on the other hand, 122 of 2140 participants with eCCr a parts per thousand yen 50 ml/min at baseline (5.7 %) fell into the eCCr < 50 ml/min during about 2 years. The incidence of renal function deterioration increased with the CHADS(2) score in the general population as well as in our patients. Renal function deterioration was not uncommon and was associated with more frequent adverse events including major bleeding in NVAF patients with anticoagulation therapy. CHADS(2), CHA(2)DS(2)-VASc, and HAS-BLED scores may be useful as an index of predicting renal function deterioration.