Association of Anticoagulant Use with COVID-19 Diagnosis

Background

The Coronavirus Disease 2019 (COVID-19) pandemic has challenged anticoagulation providers with providing optimal care while minimizing exposure risk, specifically in the management of patients on chronic warfarin. Here we provide data regarding our experience with managing patients on chronic anticoagulants, including warfarin, within Kaiser Permanente Northern California (KPNC), a large integrated healthcare delivery system serving more than 4 million patients.

Aim

To identify whether being on anticoagulation or antiplatelet agents correlates with an increased risk of contracting COVID-19.

Methods

We identified patients within KPNC electronic medical records on either warfarin, direct oral anticoagulation (DOAC) and/or antiplatelet agents between February 25 and July 3, 2020, as well as a randomly identified control group of patients not taking anticoagulation or antiplatelet. We looked for a correlation between taking anticoagulation and antiplatelets with the risk of testing positive for COVID-19.

Results/Conclusions

Among 188,438 patients on chronic anticoagulants or antiplatelets and 188,438 controls, 1,029 patients tested positive for COVID-19 during the study period. Being on chronic anticoagulants or antiplatelets was not associated with increased risk for a positive test. Patients on warfarin (N=30,242) also had no increased risk of developing COVID-19 compared to patients not on anticoagulation or antiplatelet therapy (odds ratio 0.87, 95% confidence interval 0.64-1.17). The time in the therapeutic range (TTR) of patients on warfarin during the COVID-19 pandemic remained near 72%, consistent with prior TTR, demonstrating persistent efficacy of anticoagulation despite measures to reduce COVID-19 transmission. Our data demonstrates the safety of continuing chronic warfarin in patients during the COVID-19 pandemic.