Rivaroxaban for Venous Thrombosis in a Patient with Congenital Antithrombin Deficiency.

Congenital antithrombin (AT) deficiency is a congenital coagulopathy that predisposes to venous thromboembolism (VTE), although the number of reported patients is limited; thus, large-scale data on the efficacy of direct oral anticoagulants (DOACs) in this population are lacking. There have been case reports of DOAC use in the treatment of VTE in patients with AT deficiency; however, it remains unclear whether rivaroxaban is effective in resolving thrombus and preventing long-term recurrence in pulmonary thromboembolism (PE) associated with massive deep vein thrombosis (DVT). The patient was a 39-year-old man with a family history of thrombosis who presented with lower limb pain and was diagnosed with PE and massive DVT. Continuous treatment with rivaroxaban resulted in a relatively rapid thrombus resolution and no recurrence for 15 months. This case suggests that rivaroxaban may be useful for the treatment and long-term prevention of VTE in patients with AT deficiency with massive thrombosis.