PO26 | OUTCOMES OF DIRECT ORAL ANTICOAGULANTS IN UNUSUAL-SITE THROMBOSIS: IMPACT OF ACTIVE CANCER

S. Guglielmo¹, M. Lovisotto¹, L. Scarano¹, E. De Bon², S. Barbar² | ¹Internal Medicine, Department of Medicine, Azienda Ulss 6 Euganea, Cittadella (PD), Italy; ²Thrombotic and Hemorrhagic Disorders Unit, Department of Medicine, Azienda Ulss 6 Euganea, Cittadella (PD), Italy

Introduction. Splanchnic vein thrombosis (SVT) and cerebral venous thrombosis (CVT) represent an unusual site of thrombosis. Cancer is among the most frequent predisposing conditions for SVT and CVT and is associated with an increased risk of bleeding and poor clinical outcomes. However, evidence supporting the use of direct oral anticoagulants (DOACs) in these settings remains limited, particularly in patients with active malignancy.

Aim. To evaluate the effectiveness and safety of DOAC therapy in patients with SVT or CVT and to compare outcomes between patients with and without active cancer.

Materials and Methods. This was a single-center longitudinal observational study with retrospective inclusion and prospective follow-up. Adult patients with imaging-confirmed SVT or CVT treated with a DOAC between January 2018 and October 2025 were included. The primary outcomes were radiological recanalization (absent, partial, or complete) and thrombotic recurrences. Secondary outcomes included ISTH major bleeding, clinically relevant non-major bleeding (CRNMB), and all-cause mortality. Follow-up imaging was scheduled at 6, 12, and 18 months.

Results. Of 52 screened patients, 43 were included (median age 58 years; 46.5% male); 26 had SVT and 17 CVT, with a median follow-up of 17 months. Active cancer was present in 16 patients. Most patients received initial parenteral anticoagulation (95.3%) before switching to a DOAC after a median of 14 days. DOACs used were dabigatran (41.5%), apixaban (36.5%), rivaroxaban (17.1%), and edoxaban (4.9%). Recanalization was assessable in 41 patients (14 with active cancer) and was complete in 18 (43.9%), partial in 12 (29.3%), and absent in 11 (26.8%). Active cancer was associated with a significantly lower likelihood of any recanalization (OR 0.094, 95% CI 0.019–0.464; p=0.003) and with a longer time to recanalization (log-rank p=0.007). Two thrombotic recurrences occurred (4.7%). Clinically relevant bleeding was observed in 7 patients (16.3%), including 3 major bleeding (7.0%) and 6 CRNMB events (14.0%). Seven deaths (16.3%) occurred, all among patients with active cancer and SVT.

Conclusions. In this real-world cohort of patients with SVT or CVT treated with DOACs, thrombotic recurrence and bleeding rates were acceptable. Active cancer identified a particularly high-risk subgroup characterized by reduced recanalization and all observed deaths, supporting cancer-specific studies and tailored management in unusual-site thrombosis.