Healthcare disparities among anticoagulation therapies for severe COVID-19 patients in the multi-site VIRUS registry.

Here we analyze hospitalized and ICU COVID-19 patient outcomes from the international VIRUS registry (https://clinicaltrials.gov/ct2/show/NCT04323787). We find that COVID-19 patients administered unfractionated heparin but not enoxaparin have a higher mortality-rate (390 of 1,012 = 39%) compared to patients administered enoxaparin but not unfractionated heparin (270 of 1,939 = 14%), presenting a risk ratio of 2.79 (95% C.I.: [2.42, 3.16]; p-value: 4.45e-52). This difference persists even after balancing on a number of covariates including demographics, comorbidities, admission diagnoses, and method of oxygenation, with an increased mortality rate on discharge from the hospital of 37% (268 of 733) for unfractionated heparin vs. 22% (154 of 711) for enoxaparin, presenting a risk ratio of 1.69 (95% C.I.: [1.42, 2.00]; p-value: 1.5e-8). In these balanced cohorts, a number of complications occurred at an elevated rate for patients administered unfractionated heparin compared to patients administered enoxaparin, including acute kidney injury, acute cardiac injury, septic shock, and anemia. Furthermore, a higher percentage of Black/African American COVID patients (414 of 1,294 [32%]) were noted to receive unfractionated heparin compared to White/Caucasian COVID patients (671 of 2,644 [25%]), risk ratio 1.26 (95%CI [1.14, 1.40], p-value: 7.5e-5). After balancing upon available clinical covariates, this difference in anticoagulant use remained statistically significant (311 of 1,047 [30%] for Black/African American vs. 263 of 1,047 [25%] for White/Caucasian, p-value: 0.02, risk ratio 1.18, 95%CI [1.03, 1.36]). While retrospective studies cannot suggest any causality, these findings motivate the need for follow-up prospective research into the observed racial disparity in anticoagulant use and outcomes for severe COVID-19 patients. This article is protected by copyright. All rights reserved.