Anticoagulation Management of Splanchnic Vein Thrombosis in Myeloproliferative Neoplasms: A Global Abdominal/Splanchnic Thrombosis Retrospective Observational Study in 486 MPN Patients (GASTRO-MPN)

• Published in: Blood 2024-11, Vol.144 (Supplement 1), p.16-16
• Main Authors: How, Chi-Joan, Chrysafi, Pavlina, Ko, Amica, Zon, Rebecca, Ghorbanzadeh, Atefeh, Sastow, Dahniel L, Georgen, Maria, Prabhu, Abi, Pachpande, Vrushali, Valisekka, Sai Sudha, Agarwal, Mukul, Nayak, Amiya Ranjan, Cheong, May Anne, Iurlo, Alessandra, Cattaneo, Daniele, Chiasakul, Thita, Dhawan, Rishi, Sanfilippo, Kristen M., Hobbs, Gabriela S., Houghton, Damon E., Beckman, Joan, Baumann Kreuziger, Lisa, Tremblay, Douglas, Patell, Rushad, Lauw, Mandy N.
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2024-199107

Background: Myeloproliferative neoplasms (MPNs) are chronic leukemias with increased thrombotic risk. Venous thrombosis in MPN often occurs in atypical sites, such as splanchnic vein thrombosis (SVT), defined by thrombosis in the portal, hepatic, mesenteric, or splenic veins. Data to guide anticoagulation management of SVT in MPN patients is lacking. Objectives: The purpose of this study is to evaluate outcomes as well as the safety and efficacy of different anticoagulation strategies in MPN patients with SVT. Methods: A retrospective cohort study of MPN patients with SVT from 10 international centers was conducted. All centers performed systematic identification of adults with a World Health Organization 2016 diagnosis of an MPN (polycythemia vera [PV], essential thrombocythemia [ET], myelofibrosis [MF], prefibrotic MF, MPN-unclassifiable [MPN-U]) and confirmed SVT. Inclusion criteria were met if first SVT occurred after or within one year before MPN was diagnosed. The primary outcome was 1-year cumulative incidence of recurrent venous (VT) or arterial thrombosis (AT). Secondary outcomes included 1-year cumulative incidence of (1) major and clinically relevant non-major bleeding (CRNMB) by International Society on Thrombosis and Hemostasis criteria, (2) SVT recanalization; and (3) 1-year overall survival. Death as a competing risk was used for cumulative incidence analyses of recurrence and bleeding. Results: 486 MPN patients (median age at first SVT 51 years; 62.3% female) were identified. MPN diagnosis preceded SVT in 35.2% of patients (median time 4.8 years) and occurred simultaneously or within 1 year of first SVT in 64.8% of patients. 43.8% of patients had PV, 23.7% ET, 14.2% MF, 3.1% prefibrotic MF and 13.2% MPN-U. The most common driver mutation was in JAK2 (90.7%) followed by CALR (4.4%) and MPL (1.6%). SVT localization was isolated to portal (25.7%), hepatic (15.4%), mesenteric (1.9%), and splenic veins (4.3%), and in 51.2% of cases SVT occurred in multiple vessels. Prior VT or AT occurred in 8.8% and 4.1% of subjects, respectively. Cytoreduction (most commonly hydroxyurea [36.9%], interferon [9.6%] or JAK inhibitor [6.8%]) was started after SVT in 58.7% of newly diagnosed MPN patients and 40.6% of those with known MPN. 57.6% of patients were anticoagulated, 3.5% of patients were treated with an antiplatelet agent, and 11.7% were treated with both. The most common initial anticoagulants were vitamin K antagonists (VKA) (29.2%), direct oral antico