Risk factors of thrombotic recurrence and major bleeding in patients with intermediate-risk for recurrence of venous thromboembolism.

Prolonged anticoagulation therapy is recommended for patients with intermediate-risk for recurrence of venous thromboembolism (VTE). The current study aimed to identify risk factors of VTE recurrence and major bleeding in intermediate-risk patients. The COMMAND VTE Registry is a multicenter registry enrolled consecutive 3027 patients with acute symptomatic VTE among 29 centers in Japan. The current study population consisted of 1703 patients with intermediate-risk for recurrence. The primary outcome measure was recurrent VTE during the entire follow-up period, and the secondary outcome measures were recurrent VTE and major bleeding during anticoagulation therapy. In the multivariable Cox regression model for recurrent VTE incorporating the status of anticoagulation therapy as a time-updated covariate, off-anticoagulation therapy was strongly associated with an increased risk for recurrent VTE (HR 9.42, 95% CI 5.97-14.86). During anticoagulation therapy, the independent risk factor for recurrent VTE was thrombophilia (HR 3.58, 95% CI 1.56-7.50), while the independent risk factors for major bleeding were age ≥ 75 years (HR 2.04, 95% CI 1.36-3.07), men (HR 1.52, 95% CI 1.02-2.27), history of major bleeding (HR 3.48, 95% CI 1.82-6.14) and thrombocytopenia (HR 3.73, 95% CI 2.04-6.37). Among VTE patients with intermediate-risk for recurrence, discontinuation of anticoagulation therapy was a very strong independent risk factor of recurrence during the entire follow-up period. The independent risk factors of recurrent VTE and those of major bleeding during anticoagulation therapy were different: thrombophilia for recurrent VTE, and advanced age, men, history of major bleeding, and thrombocytopenia for major bleeding. CLINICAL TRIAL REGISTRATION: Unique identifier: UMIN000021132. COMMAND VTE Registry: http://www.umin.ac.jp/ctr/index.htm .