OBJECTIVES: There is a strong relationship between renal function and thromboembolic events for both vitamin-K antagonists and rivaroxaban in patients treated for non-valvular atrial fibrillation (NVAF). Until now, only a few studies showed evidence of effectiveness and safety of anticoagulants in routine clinical practice in Germany where Phenprocoumon is the predominantly prescribed VKA.

METHODS: Data from German sickness funds between January 1^st, 2012 and March 31^st, 2016 were extracted and a new user cohort study comparing patients treated with either rivaroxaban or vitamin K antagonist (phenprocoumon) was conducted. A multivariate Cox-regression was performed to calculate adjusted hazard ratios (HR) for the risk of ischemic stroke as well as intracranial hemorrhage in the overall population as well as in patients with renal impairment.

RESULTS: DS-VASC score: 3.49; median observation time: 275 days) and 20,513 patients on phenprocoumon (mean CHADS-VASC score: 3.78; median observation time: 160 days). Of these, 1,954 patients on rivaroxaban and 3,871 patients on phenprocoumon were coded as renally impaired. A significant risk reduction for ischemic stroke rivaroxaban vs. phenprocoumon was found in the overall population; HR: 0.77 (0.63; 0.93); p<0.05. For renally impaired patients the HR was 0.85 (0.56; 1.28); p=0.428; for intracranial hemorrhage 0.86 (0.54; 1.23); p=0.403 and 0.531 (0.21; 1.33); p=0.176 respectively.

CONCLUSIONS: The analysis of the overall population showed a significant reduction in stroke risk for rivaroxaban. Although the number of patients with renal impairment in this study is still low, point estimates indicate a strong protective trend regarding effectiveness and safety of rivaroxaban vs. phenprocoumon. Additionally, the follow-up time on treatment with rivaroxaban was remarkably higher than for phenprocoumon. This study is the first focusing on a renally impaired subgroup of patients with NVAF in Germany.