Safety, efficacy, and response predictors of anticoagulation for the treatment of nonmalignant portal-vein thrombosis in patients with cirrhosis: a propensity score matching analysis

Background/Aims: Portal-vein thrombosis (PVT) develops in 10-25% of cirrhotic patients and may aggravate portal hypertension. There are few data regarding the effects of anticoagulation on nonmalignant PVT in liver cirrhosis. The aim of this study was to elucidate the safety, efficacy, and predictors of response to anticoagulation therapy in cirrhotic patients. Methods: Patients with liver cirrhosis and nonmalignant PVT were identified by a hospital electronic medical record system (called BESTCARE). Patients with malignant PVT, Budd-Chiari syndrome, underlying primary hematologic disorders, or preexisting extrahepatic thrombosis were excluded from the analysis. Patients were divided into two groups (treatment and nontreatment), and propensity score matching analysis was performed to identify control patients. The sizes of the thrombus and spleen were evaluated using multidetector computed tomography. Results: Twenty-eight patients were enrolled in this study between 2003 and 2014: 14 patients who received warfarin for nonmalignant PVT and 14 patients who received no anticoagulation. After 112 days of treatment, 11 patients exhibited significantly higher response rates (complete in 6 and partial in 5) compared to the control patients, with decreases in thrombus size of > 30%. Compared to nonresponders, the 11 responders were older, and had a thinner spleen and fewer episodes of previous endoscopic variceal ligations, whereas pretreatment liver function and changes in prothrombin time after anticoagulation did not differ significantly between the two groups. Two patients died after warfarin therapy, but the causes of death were not related to anticoagulation. Conclusions: Warfarin can be safely administered to cirrhotic patients with nonmalignant PVT. The presence of preexisting portal hypertension is a predictor of nonresponse to anticoagulation.