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671 Treatment of Portal, Mesenteric, and Splenic Vein Thrombosis with Rivaroxaban: A Pilot, Prospective Cohort Study

Program: Oral and Poster Abstracts
Type: Oral
Session: 332. Anticoagulation and Antithrombotic Therapies
Hematology Disease Topics & Pathways:
Anticoagulant Drugs, Clinical Trials, Non-Biological, Clinical Research, Therapies
Monday, December 13, 2021: 3:45 PM

Nicoletta Riva, MD, PhD1*, Jan Beyer-Westendorf, MD, PhD2, Laura Contino, MD3*, Eugenio Bucherini, MD4*, Maria Teresa Sartori, MD5*, Elvira Grandone, MD, PhD6*, Rita Carlotta Santoro, MD7*, Marc Carrier, MD8, Aurelien Delluc, MD, PhD9*, Valerio De Stefano10*, Fulvio Pomero, MD11*, Alberto Tosetto, MD12*, Cecilia Becattini, MD13*, Ida Martinelli, MD, PhD14*, Barbara Nardo, MD15*, Laurent Bertoletti, MD16*, Marcello Di Nisio, MD, PhD17*, Alejandro Lazo-Langner, MD, MSc, FRCPC18, Alessandro Schenone, MD19* and Walter Ageno, MD20*

1Department of Pathology, Faculty of Medicine and Surgery, University of Malta, Qormi, Malta
2Division of Hematology, Dresden University Hospital, Dresden, Germany
3A.O. SS. Antonio e Biagio" Hospital, Alessandria, AL, Italy
4SS Aziendale di Angiologia Faenza AUSL Romagna, Faenza (RA), Italy
5Azienda Ospedaliera Universitaria di Padova, Padova, Italy
6IRCCS Ospedale Casa Sollievo Della Sofferenza, San Giovanni Rotondo, Italy
7Azienda Ospedaliera Pugliese-Ciaccio, Catanzaro, Italy
8Department of Medicine, University of Ottawa, Ottawa, ON, Canada
9Department of Medicine, University of Ottawa/The Ottawa Hospital, Ottawa, ON, Canada
10Section of Hematology, Department of Radiological and Hematological Sciences, Catholic University, Fondazione Policlinico A Gemelli, IRCCS, Rome, Italy
11Division of Internal Medicine, Michele and Pietro Ferrero Hospital, Verduno, Italy
12Hemophilia and Thrombosis Center, Hematology Department, S. Bortolo Hospital, Vicenza, Italy
13University of Perugia, Perugia, Italy
14Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, MI, Italy
15Department of Medicine I, Busto Arsizio Hospital, Busto Arsizio, Italy
16Service De Médecine Vasculaire Et Thérapeutique, CHU De St-Etienne, St-Etienne, France
17Department of Medicine and Ageing Sciences, "G. D'Annunzio" University of Chieti-Pescara, Chieti, Italy
18Division of Hematology, London Health Sciences Centre, London, ON, Canada
19Galliera Hospital, Genoa, Italy
20Department of Medicine and Surgery, University of Insubria, Varese, Italy

Introduction: Anticoagulation plays a crucial role in the treatment of splanchnic vein thrombosis (SVT), including thrombosis of the portal (PVT), mesenteric (MVT) and splenic (SpVT) veins. Rivaroxaban is a potential alternative to heparins and vitamin K antagonists (VKA) in these patients, but data to support its use are scant. Several recent guidelines highlighted the limited evidence available for the use of the direct oral anticoagulants in these patients. In addition, despite anticoagulation, SVT patients carry high risk of recurrent venous thromboembolic events.

The aim of this study was to evaluate the safety and efficacy of rivaroxaban for the acute-phase treatment of SVT (first 3 months of treatment).

Methods: RIVASVT-100 (NCT02627053) was a prospective cohort study of adult patients with a first episode of symptomatic, objectively diagnosed PVT, MVT or SpVT. Exclusion criteria were known liver cirrhosis, Budd-Chiari syndrome, previous or ongoing variceal bleeding, portal cavernoma, thrombocytopenia, severe renal failure, life expectancy <3 months, concomitant interfering medications, treatment with therapeutic dose of heparins for >7 days, ongoing VKA treatment.

Patients received rivaroxaban 15 mg twice daily for 3 weeks, followed by 20 mg once daily for a total of 3 months. Afterwards, the decision to continue any available anticoagulant drug was left to the discretion of the attending physicians. Follow-up was performed at 3 weeks, 2 months, 3 months and 6 months.

Primary outcome was the occurrence of ISTH-defined major bleeding events during the 3 months of active treatment and up to 2 days after the end of study treatment. Secondary outcomes included death, clinically relevant non-major bleeding (CRNMB), recurrent SVT or symptomatic venous thromboembolism in other sites. We here report the results of the 3-month follow-up.

Results: Between June 2015 and March 2021, 103 patients were enrolled from 18 participating centres. After excluding 3 patients who did not meet the criteria for eligibility, 100 patients were included in the analysis. Mean (SD) age was 54.4 (± 15.5) years; 64% were males. Overall, 74% of patients had PVT, 61% MVT and 48% SpVT; 53% of SVT occurred in multiple sites. The most common risk factors were abdominal inflammation/infection (26%), followed by solid cancer (9%), overt myeloproliferative neoplasms (9%) and oestrogen hormonal therapy (9%), while 43% of cases were unprovoked. The JAK2 V617F mutation was detected in 13 out of 50 tested patients (26%).

Rivaroxaban was the sole anticoagulant agent used in 21% of patients, whereas the remaining received a combination of anticoagulants, which included low molecular weight heparin, unfractionated heparin or fondaparinux for a median of 5.0 days before transitioning to rivaroxaban.

Three patients were lost to follow-up but known to be alive at the end of the study. At 3-month follow-up, 1 (1.0%) patient died due to a non-SVT related cause. Two patients (2.06%; 95% CI, 0.57-7.21) had major bleeding events (both gastrointestinal), while 3 patients (3.09%) had CRNMB. There were 2 recurrent SVT (2.06%) during rivaroxaban treatment, one of these occurred in a patient with metastatic solid cancer. The 6-month follow-up for the last enrolled patient is ongoing.

Conclusions: Rivaroxaban appears to be safe and effective for the acute-phase treatment of SVT in non-cirrhotic patients.

Disclosures: Beyer-Westendorf: Bayer: Other: Personal fees; Daiichi Sankyo: Other: Personal fees; Pfizer: Other: Personal fees; Portola-Alexion: Other: Personal fees. Carrier: Sanofi: Honoraria; Leo Pharma: Honoraria, Research Funding; Servier: Honoraria; Bayer: Honoraria; Pfizer: Honoraria, Research Funding; BMS: Honoraria, Research Funding. Bertoletti: BMS: Honoraria, Other: Personal Fees; Pfizer: Honoraria, Other: Personal fees; Aspen: Other: Personal Fees; Bayer: Other: Personal Fees; Leo Pharma: Other: Personal Fee. Di Nisio: Bayer, Daiichi Sankyo, BMS-Pfizer, Leo Pharma, and Sanofi: Other: Personal fees. Ageno: Bayer: Research Funding; Bayer, Portola, Janssen, Aspen, Norgine, Sanofi.: Other: Advisory Board.

OffLabel Disclosure: The use of rivaroxaban in splanchnic vein thrombosis is off label in most countries.

*signifies non-member of ASH