Low prevalence of Post-thrombotic syndrome in patients treated with rivaroxaban.

Post-thrombotic syndrome (PTS) is a complication of deep vein thrombosis (DVT). Residual vein thrombus (RVT) on Doppler Ultrasound can be associated with PTS. Limited data are available on the effect of direct oral anticoagulants (DOACs) on the long-term outcome of PTS. This study aimed to compare the prevalence of PTS and RVT, in patients with previous DVT treated with rivaroxaban or enoxaparin/warfarin. A total of 129 patients with previous proximal lower limb DVT and treated with rivaroxaban (n = 71) or enoxaparin/warfarin (n = 58) for at least 3 months were included. The Villalta scale for PTS was performed after treatment. The median duration of the DVT symptoms before anticoagulation was 7 days for both groups. The rate of PTS was 50.7% in the patients treated with rivaroxaban and 69% in the enoxaparin/warfarin group. Enoxaparin/warfarin showed an increased prevalence of PTS (P = .018). An analysis in 3 different models showed that the relative risk of PTS decreased by 76% with rivaroxaban use when compared with enoxaparin/warfarin treatment. In addition, 93 of the 129 patients were evaluated regarding the presence of RVT, of which, 11 (24.4%) and 31 (64.6%) presented with RVT for rivaroxaban and enoxaparin/warfarin, respectively (P < .0001). The RVT analysis excluded the possibility of RVT as a mediator of the association between type of treatment and PTS when comparing rivaroxaban with enoxaparin/warfarin (odds ratio (OR) = 0.14; 95% confidence interval (CI): 0.1-1.0, P = .051) with rivaroxaban compared with enoxaparin/warfarin. Rivaroxaban treatment was associated with a lower risk of PTS when compared to enoxaparin/warfarin; RVT however, was not a mediator in the association between PTS and type of treatment.