PO104 | BLEEDING AND THROMBOTIC OUTCOMES DURING EXTENDED DIRECT ORAL ANTICOAGULANT THERAPY: AN EIGHT YEAR RETROSPECTIVE ANALYSIS

G. Sottilotta¹, G. Praticò¹, S. Cuzzocrea¹, D. Megalizzi¹, F. Luise² | ¹UOSD Microcitemie - Emostasi e Trombosi. Grande Ospedale Metropolitano di Reggio Calabria, Italy; ²Laboratorio Analisi. Grande Ospedale Metropolitano di Reggio Calabria, Italy

Introduction. The optimal duration of anticoagulant therapy after deep vein thrombosis remains a matter of clinical debate. Standard treatment for acute venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, typically ranges from 3 to 6 months, whereas patients with persistent risk factors, recurrent events, thrombophilia, or post‑thrombotic syndrome often require extended or indefinite therapy. Whether prolonged anticoagulation effectively reduces the risk of recurrent thromboembolic events while maintaining an acceptable bleeding profile continues to be a relevant clinical question. The introduction of direct oral anticoagulants (DOACs), particularly reduced‑dose regimens such as rivaroxaban 10 mg and apixaban 2.5 mg, has provided new options for long‑term secondary prevention. The aim of this study was to evaluate the incidence of thromboembolic and hemorrhagic events in a real‑world cohort of patients followed at the Hemostasis and Thrombosis Service of Reggio Calabria who continued DOAC therapy beyond six months from diagnosis.
Methods. We retrospectively analyzed clinical data from 201 patients (104 males, 97 females; mean age 63.5 years, range 22–91) managed at our center between November 2017 and September 2025. The mean duration of anticoagulant therapy was 1285.1 days (range 180–3944). All patients were treated for secondary prevention of lower‑limb venous thrombosis; 79 had experienced a single VTE episode, while 122 had a history of multiple events. A total of 66 patients had either congenital or acquired thrombophilia, and 4 had comorbidities associated with increased thrombotic risk. Demographic and clinical characteristics are summarized in Table 1.
Results. During follow‑up, 9 bleeding events were recorded, including 8 minor episodes (2 epistaxis, 2 rectal bleeding, 2 menorrhagia, 1 gingival bleeding, and 1 microscopic hematuria) and 1 major event (vitreous hemorrhage), which led to discontinuation of anticoagulation. Four cases of superficial thrombophlebitis occurred, prompting escalation from prophylactic to therapeutic DOAC dosing. The cumulative incidence of bleeding events was 4.5% (9/201), while thrombotic events occurred in 2.0% (4/201). When expressed as incidence rates per person‑time, bleeding events occurred at 1.27 per 100 patient‑years and thrombotic events at 0.57 per 100 patient‑years.
Conclusions. In this real‑world cohort, extended anticoagulation well beyond the conventional 3–6‑month period was associated with a low incidence of both thrombotic and hemorrhagic complications in patients considered at elevated risk of recurrence. Although bleeding events were numerically more frequent than thrombotic events, the absolute rates of both outcomes remained low. Interpretation should consider the limited number of events and the resulting wide confidence intervals. Future comparative analyses involving patients treated with DOACs lacking dedicated prophylactic dosing, as well as those maintained on vitamin K antagonists, may help clarify the relative safety and effectiveness of different long‑term anticoagulation strategies.