Resolution of acute lower extremity deep vein thrombosis with rivaroxaban compared to warfarin.

Thrombosis resolution is an important component of treatment for deep vein thrombosis (DVT) and multiple anticoagulants are now available. It is unknown whether rivaroxaban contributes to a higher degree of thrombus resolution compared to conventional anticoagulation with warfarin. Our objective was to compare thrombus resolution for rivaroxaban versus warfarin treated patients with acute lower extremity DVT. Consecutive patients treated for proximal or distal lower extremity DVT with rivaroxaban were identified from the Mayo Thrombophilia Clinic Anticoagulants Registry (November 2015-June 2016) and compared to patients treated with warfarin. Ultrasonography/Doppler images were analyzed by two independent radiologists blinded to anticoagulant and using a standardized assessment algorithm. A total of 111 patients with DVT were studied. Sixty-three rivaroxaban treated patients were compared to 48 warfarin treated patients over a median follow up of 92 and 97 days, respectively. Percentage of patients with total or partial resolution of thrombosis was similar in rivaroxaban and warfarin treated groups (95.2% vs. 91.7%, p = 0.46, respectively); also the proportion of patients with total thrombus resolution was not significantly different (38.1% vs. 29.2%, p = 0.42, respectively). There was no significant difference in the proportion of patients with no thrombus resolution between rivaroxaban and warfarin treated groups either (4.8% vs. 2.1%, p = 0.63). Thrombus propagation with warfarin therapy was observed in 6.3% of patients treated with warfarin and in none of the patients from the rivaroxaban group (p = 0.08). Resolution of acute lower extremity DVT in patients treated with rivaroxaban is similar to those treated with warfarin.