Long term survival at 6 and 12 months in venous thromboembolic disease in patients anticoagulated with rivaroxaban and warfarin: propensity score matching study

Background: Venous thromboembolic disease (VTE) is characterized by the obstruction of venous blood flow by a thrombus, whose survival data and clinical outcomes, such as disease recurrence and bleeding in patients with warfarin anticoagulant therapy compared with rivaroxaban in the Latin American population is limited. Methods: A retrospective cohort study with propensity score matching analysis was conducted in patients with VTE anticoagulated with warfarin or rivaroxaban treated. The radiological report defined VTE with a confirmed diagnosis of pulmonary embolism and deep ve. Survival analysis was performed using a Kaplan-Meier curve for each of the intervention groups, and it was compared using a log-rank test. Results: Of 2193 potentially eligible patients with a suspected diagnosis of VTE, 505 patients entered the analysis; of these, 285 subjects were managed with warfarin and 220 anticoagulated with rivaroxaban. Bleeding at six months occurred in 2.7% (6/220) of patients on rivaroxaban vs. 10.2% (29/258) on warfarin in the unmatched population (p=0.001) and in 2.9% (6/209) with rivaroxaban and 11.0% (23/209) with warfarin in the pairing (p=0.001). At 6 and 12 months, there was a survival of 97.1% for rivaroxaban and 97.6% for warfarin 97.6% (p=0.76), and 94.7% for rivaroxaban and 95.7% for warfarin (p=0.61), respectively. Conclusion: Rivaroxaban, compared to warfarin in VTE management, has no impact in terms of survival at 6 and 12 months, nor a decrease in the occurrence of new thromboembolic episodes. However, it decreases the risk of bleeding at six months.