Therapeutic vs. prophylactic anticoagulation in COVID-19 patients: a systematic review and meta-analysis of real-world studies

INTRODUCTION: Coagulopathy, in the form of either venous or arterial thromboembolism, is one of the most se-vere sequelae of coronavirus disease (COVID-19) and has been associated with poorer outcomes. However, the role of therapeutic anticoagulation (tAC) or prophylactic anticoagulation (pAC) in COVID-19 patients has not been definitely established. Therefore, the aim of this systematic review and meta-analysis was to gather all the available real-world data in the field and to provide a reliable effect size of the effect on mortality of tAC compared to pAC in COVID-19 patients.EVIDENCE ACQUISITION: Real-world studies (RWS) were identified by searching electronic databases from incep-tion to 31st October, 2021. Randomized controlled trials were excluded. Mortality and bleedings were considered as primary and secondary outcomes, respectively. EVIDENCE SYNTHESIS: 10 RWS and 5541 patients were included in the analysis. Overall, tAC was associated with lower mortality (HR=0.62, 95% CI: 0.54-0.71). There was asymmetry at the funnel plot suggesting publication bias, that was not confirmed at the Egger test (P=0.07). For the secondary endpoint, there was a non-statistically significant ten-dency for more bleedings in patients treated with tAC compared to pAC (RR=1.75, 95% CI: 0.81-3.81).CONCLUSIONS: Our meta-analysis, based on RWS and adjusted estimates of risk, suggests a survival benefit of tAC over pAC in COVID-19 patients in the real world.