The Clinical Outcomes of COVID-19 in Patients on Warfarin: A Propensity Score Matching Study

BACKGROUND: COVID-19 is associated with vascular thrombosis in critical patients. However, warfarin has not been adequately studied in patients with COVID-19. This study aimed to evaluate whether the use of warfarin, a potent oral anticoagulant, was of clinical benefit in patients with COVID-19. METHODS: This was a retrospective cohort study of COVID-19 patients diagnosed at 3 different centers in Turkey between April 2020 and April 2021. Patients were grouped by whether they were taking warfarin or not. Propensity score matching analysis was used to compare the dif ferences between the groups in mortality, hospitalization, and admission to the intensive care unit. RESULTS: A propensity score analysis was performed on 128 patients in the warfarin group and 372 patients in the control group. After matching, 84 pairs of patients were compared. The patients in the control group were more likely to be admitted to the intensive care unit (33.3% vs. 14.3%, respectively;P=.007) and had longer hospital stays than the warfarin group (7.1 vs. 14.1 days;P=.005). The warfarin group had a lower death rate compared to the control group (7.1% vs. 27.4%, respectively;P=.001), and surviving patients were sig nificantly more likely to be in the warfarin group than the control group (56.1% vs. 20.7%, respectively;P=.001). In patients on warfarin, there was a lower incidence of in-hospital death (log-rank test P=.005). CONCLUSIONS: Warfarin therapy could provide clinical benefits in patients with COVID-19. The current data highlight the importance of potent anticoagulation in the treatment of COVID-19.