ABSTRACT
INTRODUCTION: Thromboembolic events are one of the important complications in COVID-19 patients, especially in severe cases. Aspirin affects platelet function by irreversibly inhibiting cyclooxygenase activity, reducing the risk of thrombosis. The current systematic review aimed to evaluate aspirin's effectiveness in preventing pro-thrombotic states in COVID-19 hospitalized patients. METHODS: The systematic search was done in PubMed/Medline, EMBASE, and Medrxiv until September 27, 2021. The following keywords were used: "COVID-19", "SARS-CoV-2", "2019 Novel Coronavirus", "Aspirin," and "Acetylsalicylic Acid." RESULTS: Twelve studies were included. In COVID-19 patients, aspirin can reduce CRP, IL-6 levels, and platelet aggregation by inhibiting thromboxane A2. It can also improve antiviral immunity by hindering the biosynthesis of prostaglandins and lipoxin. Eight out of twelve articles indicated that aspirin provided a beneficial effect on COVID-19. Most studies consider lowered mechanical ventilation needs, ICU admission, illness severity, overt thrombosis, and clinical outcomes in COVID-19 patients receiving aspirin. CONCLUSION: Aspirin as an antiplatelet and anti-inflammatory agent may reduce the mortality rates in hospitalized patients with severe COVID-19. Further observational studies are necessary to determine the effect of aspirin on the prevention of pro-thrombotic states in hospitalized COVID- 19 patients.