Epidemiology and 3-year outcomes of combined oral contraceptive-associated distal deep vein thrombosis

Background: Distal deep vein thrombosis (infrapopliteal DVT without proximal DVT or pulmonary embolism [PE]) generally shares the same triggering risks factors as proximal DVT. In women of childbearing age, a frequent triggering risk factor is the use of combined oral contraceptive (COC) pills. However, data on the epidemiology and long-term outcomes of COC-associated distal DVT are lacking.

Objectives: To assess the epidemiology and long-term outcomes of COC-associated distal DVT.

Methods: Using data from the OPTIMEV (Optimisation de l'Interrogatoire dans l'évaluation du risque thrombo-Embolique Veineux [Optimization of Interrogation in the Assessment of Thromboembolic Venous Risk]) multicenter cohort study of patients with objectively confirmed venous thromboembolism (VTE) enrolled between 2004 and 2006, we assessed in nonpregnant or postpartum women aged ≤ 50 years without cancer or history of VTE (i) proportion of COC-associated distal DVTs among women with distal DVTs and among women with COC-associated VTEs (distal DVT, proximal DVT, or PE) and (ii) 3-year incidence of death, bleeding, and VTE recurrence.

Results: COC-associated distal DVTs (n = 54) represented 43.9% of all distal DVTs and 51.9% of COC-associated VTEs. All but one woman with a COC-associated distal DVT received therapeutic anticoagulation for a median of 3 months. At 3-year follow-up, all women with COC-associated distal DVTs were alive, and none had bled during anticoagulant treatment or had experienced a DVT or PE recurrence after stopping anticoagulants. Similar results were found in patients with COC-associated proximal DVT and PE: The VTE recurrence rate was 1.7% per patient-year (PY) and 0% PY, respectively, and there were no deaths or major bleeds in either group.

Conclusions: Distal DVT was the most frequent clinical presentation of COC-associated VTE and had similarly favorable long-term outcomes as other COC-associated VTE.