Chronic Anticoagulant Use Prior to Covid-19 Diagnosis: A Systematic Review and Meta-Analysis

ABSTRACT

INTRODUCTION: Coagulopathy and thromboembolic events are poor prognostic indicators of COVID-19 disease. There is a discrepancy in the results of different studies regarding the effects of chronic anticoagulation on clinical outcomes. This systematic review aims to summarize the evidence on the impact of chronic anticoagulation on clinical outcomes in COVID-19. METHOD(S) A Literature search was performed on LitCovid PubMed, WHO, and Embase databases from inception (December 2019) till May 2022. Our eligibility criteria included original studies that reported the association between prior use of anticoagulants for unrelated indications at the time of COVID-19 diagnosis and the patient outcomes in adults suffering from COVID-19. The risk of thromboembolic events in COVID-19 infected patients on chronic anticoagulation is the primary outcome and severity of COVID-19 disease in terms of ICU admission or invasive mechanical ventilation/intubation requirements, and all-cause mortality were the secondary outcomes. Random effects models were used to compute crude ODDs ratios (OR) and adjusted odds ratios (aOR) with 95% confidence intervals (CIs). RESULT(S) A total of 44 observational studies met our inclusion criteria. In unadjusted analysis, prior anticoagulation was not associated with reduced risk of thromboembolic events in COVID-19 patients (N=43851, 9 studies, OR 0.67 [0.22, 2.07];p= 0.49;I2= 95%). However, pre-hospital use of anticoagulants significantly increase the risk of allcause mortality in COVID-19 patients (N= 580601;37 studies, OR 1.56 [1.22, 2.01];p=0.0005;I2= 97%). There was no statistically significant association between prehospital anticoagulants usage and COVID-19 disease severity (N=186239;20 studies, OR 0.96 [0.70, 1.33];p= 0.82;I2= 88%). Pooling adjusted estimates revealed no statistically significant association between pre-hospital use of anticoagulants and risk of Thromboembolic events in COVID-19 patients (aOR= 0.85 [0.34, 2.12];p= 0.72), COVID-19 related mortality (aOR= 0.93 [0.82, 1.07];p= 0.32), and the severity of COVID-19 infection (aOR= 0.96 [0.72, 1.30];p= 0.81). CONCLUSION(S) Prehospital use of anticoagulation was not significantly associated with reduced risk of thromboembolic events, improved survival, and lower severity of disease in COVID-19 patients.