OC 23.5 - Progression of anticoagulant-related nephropathy after initiating anticoagulant therapy

Background: Anticoagulant-related nephropathy (ARN) is a potentially serious complication in patients receiving anticoagulant treatment. Many multi-center studies indicate that ARN occurs in up to 30 % of patients exposed to supratherapeutic INR when treated with vitamin K antagonists but little is known about ARN in DOACs.

Aims: We aimed to determine the incidence of ARN in patients with atrial fibrillation initiating (AF) oral anticoagulant treatment.

Methods: We included consecutive anticoagulant-naive patients with AF referred to our center. Before initiation and after 6 months of treatment, urine and blood samples were collected. We defined ARN as a rise in serum creatinine by at least 27 mmol/l or by 50 % after initiation of anticoagulant therapy. We also followed concentration of cystatin C and presence of proteinuria and erythrocyturia as markers of renal damage.

Results: We included 126 consecutive patients. All patients required anticoagulant treatment for AF. Patients received apixaban 51 (40.4%), rivaroxaban 35 (27.8%), dabigatran 26 (20.6%) or warfarin 14 (11.2%) (Table 1). None of the patients received DOAC developed ARN. The only significant difference was a slight rise in concentration of cystatin C but the absolute difference was negligible. Despite the similar basal renal function between the warfarin and DOAC groups, the sCr level was higher and the eGFR was lower in patients with warfarin than DOAC group after follow-up period. The independent risk factors for the development of warfarin related nephropathy (WRN) in this study were coexisting congestive heart failure (CHF) and low serum basal albumin level.

Conclusion(s): ARN appears to be rare during the follow-up period after initiating anticoagulant treatment. It is noteworthy that irrespective of renal function, a lower basal serum albumin level and comorbidity such as CHF were independent predictors of WRN. These data are from single medical center and multicenter randomized controlled trials are required to obtain more detailed findings.