Clinical outcome of patients with venous thromboembolism on Rivaroxaban versus vitamin K antagonists : A preliminary report from Douala, Cameroon

Abstract

Background: Direct Oral Anticoagulants (DOACs) which are increasingly used for the management of Venous Thromboembolism (VTE) have demonstrated efficacy and safety in clinical trials. However, little is known on outcomes in those managed with DOACs compared to Vitamin K Antagonists (VKAs) in routine clinical practice in Africa. In this preliminary study, we sought to compare the non-fatal clinical outcomes in VTE patients managed with Rivaroxaban versus VKAs in Douala.

Materials and Methods: This preliminary study analyzed medical records of VTE patients managed with oral anticoagulants over a 3-year retrospective period in Douala General Hospital and Douala Cardiovascular Center. Outcomes of interest included bleeding, recurrent VTE and post-thrombotic syndrome. Data was analyzed using SPSS version 23.

Results: Eighty-seven medical records were identified; Deep venous thrombosis (DVT) was diagnosed in 36.8% and 13.8% had both DVT and pulmonary embolism. Rivaroxaban was prescribed in 77% of cases. We included 82 medical records for the outcome analysis. Adverse clinical outcomes were recorded in 19 (23.2%) medical records amongst which 15 (78.9%) in the Rivaroxaban group. All (4 patients) who bled, 6 (66.7%) patients who had VTE recurrence and 5 (71.4%) patients with post-thrombotic syndrome were managed with Rivaroxaban, however, these were not statistically significantly different from those managed with VKAs. No predictor of clinical outcome was identified. Though more outcomes occurred within 30 days of oral anticoagulation, this was not statistically significant.

Conclusion: Three-quarters of VTE patients were managed with Rivaroxaban. Although more bleeding was observed with rivaroxaban group, clinical outcomes were similar with VKA group. This seeds the idea of a prospective study in real life with a larger sample size in Africa.

Keywords: Outcomes, Deep vein thrombosis, pulmonary embolism, Venous thromboembolism, Oral anticoagulation, Cameroon