Thrombosis and bleeding outcomes with warfarin conversion to rivaroxaban during the COVID-19 pandemic

Abstract

Background. In 2020, during the coronavirus disease 2019 (COVID‐19) outbreak, eligible patients were converted from warfarin to rivaroxaban therapy to limit the transmission of COVID‐19 infection. Objective. To assess the thrombosis and bleeding outcomes associated with converting patients on warfarin therapy to rivaroxaban during the COVID‐19 pandemic. Methods. A retrospective audit was performed that identified 190 participants with venous thromboembolism (VTE) and 112 participants with non‐valvular atrial fibrillation at the anticoagulation clinic service at Charlotte Maxeke Johannesburg Academic Hospital, South Africa. Participants were converted to rivaroxaban 20 mg for a median (interquartile range) period of 4 (2) months between April and October 2020. Follow‐ups were conducted telephonically and face‐to‐face on conversion back to warfarin. Rates of COVID‐19 infections, bleeding and thrombosis were objectively confirmed. Results. The COVID‐19 infection rate among participants was 3.3% (95% confidence interval (CI) 1.6 ‐ 6.0), with five (1.7%) hospital admissions and two (0.7%) COVID‐19‐related deaths. The deaths occurred in one participant on rivaroxaban, and in another after switching back to warfarin. One week after switching to rivaroxaban, the rate of clinically relevant non‐major bleeding was 0.7% (95% CI 0.02 ‐ 2.54), while minor bleeding occurred at a rate of 9.2% (95% CI 6.16 ‐ 13.40). No major bleeding events were reported, and bleeding rates on rivaroxaban were not significantly higher compared with warfarin. Additionally, two (0.7%) myocardial infarctions were recorded. One occurred on rivaroxaban and the other after switching back to warfarin. A single (0.3%) VTE presenting as a newly diagnosed pulmonary embolism was reported in a participant on rivaroxaban. Conclusion. This study provides practical insights regarding the conversion of eligible participants from warfarin to rivaroxaban during the first wave of COVID‐19, with the aim of informing future public health interventions in similar crisis settings.