Incidence of bleeding and recurrence in isolated distal deep vein thrombosis: findings from the Venous Thrombosis Registry in ?stfold Hospital

Background: Isolated distal deep vein thrombosis (IDDVT) is a common presentation of deep vein thrombosis. There are limited data on the long-term risk of recurrence after IDDVT.Objectives: We aimed to determine the short-and long-term incidence of venous thrombosis (VTE) recurrence after cessation of anticoagulation and the 3-month incidence of bleeding during anticoagulant treatment in patients with IDDVT. Methods: Between January 2005 and May 2020, 475 patients with IDDVT and without active cancer were identified from the Venous Thrombosis Registry in ostfold Hospital, which is an ongoing registry of consecutive patients with VTE at ostfold Hospital, Norway. Major and clinically relevant, nonmajor bleeding as well as recurrent VTE were registered, and the cumulative incidences of these events were assessed.Results: The median age of the patients was 59 years (IQR, 48-72 years), 243 (51%) patients were women, and 175 events (36.8%) were classified as unprovoked. The 1-, 5-, and 10-year cumulative incidences of recurrent VTE were 5.6% (95% CI, 3.7-8.4), 14.7% (95% CI, 11.119.4), and 27.2% (95% CI, 21.1-34.5), respectively. The recurrence rates were higher for unprovoked IDDVT than for provoked IDDVT. Among the recurrent events, 18 (29%) were pulmonary embolisms and 21 (33%) were proximal deep vein thromboses. The 3-month cumulative incidence of major bleeding was 1.5% (95% CI, 0.7-3.1) overall and 0.8% (95% CI, 0.2-3.1) when restricted to patients treated with direct oral anticoagulants.Conclusion: Despite initial treatment, the long-term risk of VTE recurrence after first-time IDDVT is high. The bleeding rates during anticoagulation, particularly with direct oral anticoagulants, were acceptably low.