DOACs vs warfarin: Rethinking anticoagulation strategies for portal vein thrombosis prophylaxis in patients with increased risk.

Abstract

e23352 Background: Portal vein thrombosis (PVT)—the formation of a thrombus within the portal vein or its branches (superior mesenteric and splenic veins)—arises from local and systemic prothrombotic factors, including cirrhosis, hepatobiliary malignancies, myeloproliferative disorders, and inflammatory abdominal diseases. While PVT occurs in less than 1% of the general population, its prevalence rises to 20% in advanced liver disease, particularly among liver transplant candidates. Anticoagulation is central to PVT management, with warfarin traditionally used for prophylaxis and treatment. However, direct oral anticoagulants (DOACs) have garnered interest as a more convenient and potentially safer alternative. This study reviews the efficacy, safety, and practicality of warfarin versus DOACs for PVT prevention in cirrhotic patients, those with liver cancer, prior liver transplantation, or splenectomy, evaluating current evidence and clinical guidelines. Methods: Patients with NAFLD, liver cell carcinoma, liver transplant history, cirrhosis, thrombophilia, portal hypertension, splenectomy, or noninfective colitis were included. Two cohorts were analyzed: DOACs (apixaban/rivaroxaban) vs. warfarin. Propensity score matching balanced groups for age, sex, type 2 diabetes, hypertension, chronic kidney disease, and atrial fibrillation. The primary outcome was PVT incidence at 6 months, 1 year, and 5 years. Patients with prior PVT were excluded. Results: At 6 months, 620 warfarin-treated and 525 DOAC-treated patients developed PVT. The risk ratio was 1.191 (95% CI: 1.06–1.337), and mean PVT incidence was higher in the warfarin group (4.202) than the DOAC group (2.72) (p < 0.0001). At 1 year, 686 warfarin-treated vs. 607 DOAC-treated patients developed PVT (risk ratio: 1.14, 95% CI: 1.022–1.271). Mean incidence remained higher in warfarin users (5.211) vs. DOAC users (3.277) (p < 0.0001). At 5 years, 893 warfarin-treated vs. 867 DOAC-treated patients developed PVT (risk ratio: 1.039, 95% CI: 0.947–1.14). Mean incidence was higher in warfarin users (7.572) vs. DOAC users (4.569) (p < 0.0001). Conclusions: DOACs showed superior efficacy in preventing PVT over 6 months and 1 year, with fewer complications, reduced bleeding risks, and no need for routine monitoring, offering practical advantages. These findings support the need for updated clinical guidelines to reflect the evolving role of DOACs in PVT prophylaxis. Time Point Incidence Rate per 100 PY (Warfarin, 95% CI) Incidence Rate per 100 PY (DOAC, 95% CI) Hazard Ratio (95% CI, p-Value) 6 Months 5.1 (4.7-5.5) 3.9 (3.5-4.3) 1.22 (1.08-1.37, 0.001) 1 Year 4.8 (4.4-5.2) 3.7 (3.3-4.1) 1.16 (1.04-1.30, 0.003) 5 Years 3.2 (2.9-3.5) 2.9 (2.6-3.2) 1.07 (0.97-1.17, 0.169)