Retrospective Review on the Safety and Efficacy of Direct Oral Anticoagulants Compared With Warfarin in Patients With Cirrhosis
Purpose: Patients with cirrhosis needing anticoagulation therapy have historically been prescribed warfarin. New retrospective research has concluded that in patients with cirrhosis direct oral anticoagulants (DOACs) have similar or lower bleeding rates compared with that of warfarin. This study compares the safety and efficacy of DOACs with that of warfarin in patients with cirrhosis.
Methods: A retrospective chart review was conducted in adult patients with cirrhosis taking either apixaban, dabigatran, edoxaban, rivaroxaban, or warfarin. Exclusion criteria consisted of patients prescribed triple antithrombotic therapy (dual antiplatelet therapy plus an anticoagulant) and indications other than nonvalvular atrial fibrillation (NVAF) and venous thromboembolism (VTE). The primary endpoint was all-cause bleeding, and the secondary endpoints were failed efficacy and major bleeding as defined by the International Society on Thrombosis and Haemostasis in 2005. Failed efficacy was a combination endpoint including the development of VTE, stroke, myocardial infarction and/or death. Patient data were collected from the Computerized Patient Record System from October 31, 2014 to October 31, 2018.
Results: The study included 42 patients in the DOAC group and 37 patients in the warfarin group. Baseline characteristics were not significantly different between groups except for the Child-Turcotte-Pugh score, Model for End-Stage Liver Disease score, international normalized ratio, and number of days on anticoagulation therapy. The rate of all-cause bleeding in the DOAC group was 16.7% (n = 7) vs 21.6% (n = 8) in the warfarin group ( P = .7). The rate of major bleeding in the DOAC group was 2.4% (n = 1) vs 5.4% (n = 2) in the warfarin group ( P = .6). The rate of failed efficacy in the DOAC group was 7.1% (n = 3) compared with 8.1% (n = 3) in the warfarin group ( P = .9). Subgroup analysis of all-cause bleeding did not identify any significant trends between groups.
Conclusions: There were no statistically significant differences identified between the rates of all-cause bleeding, major bleeding, and failed efficacy between the DOACs and warfarin groups. DOACs may be a safe alternative to warfarin in patients with cirrhosis requiring anticoagulation for NVAF or VTE, but large randomized trials are required to confirm these results.
Limitations
The inability to meet power or evaluate adherence and appropriate renal dose adjustments for DOACs limited this study. This study was conducted at a single center in a predominantly male veteran population and therefore may not be generalizable to other populations. A majority of patients in the DOAC group were prescribed apixaban (69.1%), which may have affected the overall rate of major bleeding in the DOAC group. Pivotal trials of apixaban have shown a consistent decreased risk of major bleeding in patients with NVAF or VTE when compared with warfarin.14,15 Therefore, the results of this study may not be generalizable to all DOACs.
An inherent limitation of this study was the inability to collect data verifying adherence in the DOAC group. However, in the warfarin group, percentage of time within the therapeutic INR range of 2 to 3 was collected. While not a direct marker of adherence, this does allow for limited evaluation of therapeutic efficacy and safety within the warfarin group. Last, proper dosing of DOACs in patients with and without adequate renal function was not evaluated in this study.
Conclusions
The results of this study are consistent with other retrospective research and literature reviews. There were no statistically significant differences identified between the rates of all-cause bleeding, major bleeding, and failed efficacy between the DOAC and warfarin groups. DOACs may be a safe alternative to warfarin in patients with cirrhosis requiring anticoagulation for NVAF or VTE, but large randomized trials are required to confirm these results.
