Abstract: Received: 14 February 2021 | Revised: 17 April 2021 | Accepted: 26 April 2021 DOI: 10.1002/jmv.27053 RESEARCH ARTICLE Decreased in‐hospital mortality associated with aspirin administration in hospitalized patients due to severe COVID‐19 Mohammad Haji Aghajani1 | Omid Moradi2 | Hossein Amini2 | Hamed Azhdari Tehrani3 | Elham Pourheidar3 | Mohammad M. Rabiei4 | 1,5 Mohammad Sistanizad 1 Prevention of Cardiovascular Disease Research Center, Imam Hossein Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran 2 Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran 3 Department of Hematology and Medical Oncology, Shahid Beheshti University of Medical Sciences, Tehran, Iran 4 Abstract Hypercoagulability and thrombosis caused by coronavirus disease 2019 (COVID‐19) are related to the higher mortality rate. Because of limited data on the antiplatelet effect, we aimed to evaluate the impact of aspirin add‐on therapy on the outcome of the patients hospitalized due to severe COVID‐19. In this cohort study, patients with a confirmed diagnosis of severe COVID‐19 admitted to Imam Hossein Medical Center, Tehran, Iran from March 2019 to July 2020 were included. Demographics Clinical Research Development Unit of Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran and related clinical data during their hospitalization were recorded. The mortality 5 aspirin use was assessed. Nine hundred and ninety‐one patients were included, of Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran, Iran rate of the patients was considered as the primary outcome and its association with that 336 patients (34%) received aspirin during their hospitalization and 655 ones (66%) did not. Comorbidities were more prevalent in the patients who were re- Correspondence Mohammad Sistanizad, Department of Clinical Pharmacy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Valiasr St, Tehran 14155‐6153, Iran. Email: Sistanizadm@sbmu.ac.ir ceiving aspirin. Results from the multivariate COX proportional model demonstrated a significant independent association between aspirin use and reduction in the risk of in‐hospital mortality (0.746 [0.560–0.994], p = 0.046). Aspirin use in hospitalized patients with COVID‐19 is associated with a significant decrease in mortality rate. Further prospective randomized controlled trials are needed to assess the efficacy and adverse effects of aspirin administration in this population. KEYWORDS aspirin, cohort study, COVID‐19, mortality, SARS coronaviruses, thromboembolism 1 | INTRODUCTION despite using pharmacological thromboprophylaxis.1,2,5 The benefit of using the anticoagulant to decrease the risk of these complications From the beginning of the coronavirus disease 2019 (COVID‐19) and improve the survival of the patients with COVID‐19 was con- pandemic, different aspects of the disease pathology have been firmed by many studies3,6,7 but data about the effect of antiplatelet reported. Studies showed the significant effect of COVID‐19 on agents on these complications are limited.2,7 Aspirin has been com- increasing the risk of hypercoagulability and thrombosis that are monly recommended for the primary prevention of atherosclerotic associated with increased mortality.1–4 Although the incidence rate cardiovascular diseases in high‐risk..