Abstract

WANG, C-Y; SCHAPKAITZ, E; LOUW, S  and  JACOBSON, B. Thrombosis and bleeding outcomes with warfarin conversion to rivaroxaban during the COVID-19 pandemic. SAMJ, S. Afr. med. j. [online]. 2025, vol.115, n.9, pp.39-45. ISSN 2078-5135.  https://doi.org/10.7196/SAMJ.2025.v115i9.3503.

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.

Keywords : COVID-19; anticoagulation; venous thromboembolism; bleeding.

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