Treatment with rivaroxaban was effective for managing splanchnic vein thrombosis (SVT) in non-cirrhotic patients, according to the results of a study published in Blood Advances. Study results suggest the oral direct factor Xa inhibitor could serve as an alternative to standard anticoagulation for the management of this manifestation of unusual site venous thromboembolism (VTE).
Many patients with SVT are at increased risk of bleeding complications, said corresponding author Walter Ageno, MD, of the University of Insubria in Italy.
“Low-molecular-weight heparin has long been used for the initial but also long-term treatment of patients with SVT who are at a very high bleeding risk,” he explained. “Unfortunately, this option is inconvenient for long-term use because of the parenteral route of administration.”
Dr. Ageno stated that rivaroxaban features the advantage of an oral administration route without the need for laboratory monitoring. “And thanks to the relatively short half-life,” he added, “it can be more easily managed than warfarin in cases of bleeding complications.”
The study included 100 patients with a first episode of symptomatic, non-cirrhotic SVT. These patients with objectively diagnosed SVT received treatment with rivaroxaban 15 mg twice daily for three weeks. This treatment was followed by rivaroxaban 20 mg every day for three months.
Patients who had received full-dose anticoagulation for seven days or more before enrollment were excluded from the study. Major bleeding was the primary outcome, while secondary outcomes were death, recurrent SVT, and complete vein recanalization within three months.
The mean age of the overall patient cohort was 54.4 years, and most participants (64%) were men. Risk factors for SVT in the patient population were abdominal inflammation or infection (28%), solid cancer (9%), myeloproliferative neoplasms (9%), and use of hormonal therapy (9%). Approximately 43% of SVT cases were considered unprovoked. Around 26% of 50 tested patients had a JAK2V617F mutation, while 23% of patients had the prothrombin G20210A mutation and 16% had hyperhomocysteinemia.
The follow-up period was six months for all patients. At three months, major gastrointestinal bleeding was observed in two patients, there were four clinically relevant non-major bleeding events in three patients, and there was one death, which was not related to SVT. Between three and six months, one major bleeding event and two clinically relevant non-major bleeding events were reported. There was one report of symptomatic SVT recurrence on rivaroxaban treatment and two deaths, which were not related to SVT.
Rivaroxaban has several practical advantages over standard anticoagulation that help simplify therapy for patients with SVT, both during the acute phase and long-term secondary prevention, according to Dr. Ageno. He added that a high proportion of patients with SVT are at an increased risk of long-term recurrences and therefore require extended secondary prophylaxis with anticoagulant drugs, so the advantages of rivaroxaban, such as predictable and stable dose response, may improve adherence to treatment and quality of life.
Limitations of the study were the single-arm design, lack of a control group, and the potential reduced generalizability of the findings as a result of the exclusion of patients with liver cirrhosis, Budd-Chiari syndrome, or portal vein cavernoma, as well as patients with platelet counts below 100,000 mm3.
Dr. Ageno commented that there is a need to study the efficacy and safety of low-dose rivaroxaban or apixaban for extended secondary prevention after six months of SVT. He added that if low-dose rivaroxaban is confirmed to prevent recurrent VTE and reduce the risk of complications compared with standard doses, this “would be extremely clinically relevant in a high bleeding risk population, such as the population of patients with SVT.”
Any conflicts of interest declared by the authors can be found in the original article.
Ageno W, Beyer-Westendorf J, Contino L, et al. Rivaroxaban for the treatment of noncirrhotic splanchnic vein thrombosis: An interventional prospective cohort study [published online ahead of print, 2022 Apr 19]. Blood Adv. doi: 10.1182/bloodadvances.2022007397.