Three Year Follow-Up of Reduced Dose of Direct Oral Anticoagulants for Extended Treatment of Venous Thromboembolism: An Ambispective Cohort Study.

Few data are available on the outcomes of patients with venous thromboembolism (VTE) on long-term reduced dose of direct oral anticoagulants (DOACs). We evaluated the effectiveness and safety of reduced dose of DOACs for the extended treatment of VTE. In this monocenter, ambispective cohort study, 140 patients receiving a reduced dose of DOACs for VTE were included. The primary outcomes were recurrent VTE, major bleeding and clinically relevant non-major bleeding. The secondary outcomes were arterial events and minor bleedings. The incidence of the primary outcomes was calculated. The rate for secondary outcomes was descriptively reported. The mean age of the overall cohort was 72 years. Half of the patients were female, 51.4% had a persistent risk factor, 40.0% an unprovoked VTE, and 8.6% a minor transient risk factor. Most patients had lower extremity deep vein thrombosis with or without pulmonary embolism (55.0%) and received apixaban (73.6%) or rivaroxaban (14.3%) for a mean duration of 2.7 years. Regarding the primary outcomes, there was one recurrent VTE (0.7%), four major bleedings (2.9%) and two clinically relevant non-major bleedings (1.4%). Regarding the secondary outcomes, there were four acute ischemic strokes (2.9%) and two minor bleedings (1.4%). Reduced dose of DOACs was associated with a low rate of recurrent VTE and an acceptably low rate of bleeding complications. The rate of arterial events during follow-up suggests the need for an assessment of cardiovascular risk factors in this study population.