Oral anticoagulation and clinical outcomes in COVID-19. an Italian multicenter experience

Background: Since the body of evidence addressing the coagulation derangements caused by Coronavirus disease (COVID-19) has been constantly growing, we investigated whether pre-hospitalization oral anticoagulation (OAC) or in-hospital heparin treatment could have a protective role among COVID-19 patients. Method: In this cohort study, consecutive COVID-19 patients admitted to four different Italian Institutions were enrolled. Baseline demographic, clinical, laboratory, and radiological characteristics, as well as in-hospital treatment and outcomes were evaluated. The primary outcome was mortality. Results: A total of 844 COVID-19 patients were enrolled as study cohort, n = 65 (7.7%) taking OACs prior to hospitalization. Regarding clinical outcomes, OAC patients developed acute hypoxemic respiratory failure (AHRF) more frequently than non-OAC patients as well as presenting a higher mortality rate (44.6% vs 19.8%, p < 0.001). At overall multivariate logistical regression, use of heparin (n = 394, 46.6%) was associated with a better chance of survival to hospital discharge (OR 0.60 [0.38–0.94], p < 0.001), in particular in patients with AHRF, with no association found with the use of OACs. In a sub-analysis, the highest mortality rate was found for AHRF patients when heparin was not administered. Conclusion: In our cohort, OACs appeared to be ineffective in reducing mortality rate, while heparin resulted to be a useful treatment when lung disease was sufficiently severe, potentially suggesting a crucial role of microthrombosis in severe COVID-19. Due to the relatively small number of COVID-19 patients treated with OACs included in our analysis and their higher number of comorbidities, larger studies are needed in order to confirm our findings.