Effects of Aspirin Therapy in Patients Hospitalized With COVID-19

Investigators conducted a study to assess the efficacy and safety of aspirin therapy in patients hospitalized with COVID-19.

Although aspirin therapy decreased the time to discharge by 1 day in patients hospitalized with COVID-19, no significant decreases were found in regard to the risk for all-cause mortality, invasive mechanical ventilation (IVM), renal dialysis, or hemofiltration, according to results of a randomized, controlled, open-label platform trial published in The Lancet.

The trial was part of the Randomized Evaluation of COVID-19 Therapy (RECOVERY) trials that assessed the effects of potential treatments in patients hospitalized with COVID-19, such as hydroxychloroquine, azithromycin, and convalescent plasma.

Between November 2020 and March 2021, investigators conducted a study to determine the efficacy and safety of aspirin therapy for the treatment of COVID-19. They enrolled adult patients hospitalized with COVID-19 with no contraindications to aspirin therapy. Patients were randomly assigned in a 1:1 fashion to receive either standard care alone or standard care plus a 150-mg dose of oral or rectal aspirin daily. The primary outcome was all-cause mortality at 28 days. Secondary outcomes included time to hospital discharge and progression to IVM.

Among a total of 14,892 patients included in the trial, 7541 received standard care alone and 7351 received standard care plus aspirin. The mean patient age was 59.2 years (SD, 14.2), 62% were men, and the median time since symptom onset was 9 days (IQR, 6-12 days).

The investigators found that the time to hospital discharge was decreased by 1 day among patients in the aspirin group vs those in the standard care group (8 days vs 9 days). Compared with patients in the standard care group, incident thrombotic events were decreased (4.6% vs 5.3%) and incident major bleeding events were increased (1.6% vs 1.0%) among those in the aspirin group.

No significant differences were noted in regard to all-cause mortality outcomes between patients in the aspirin vs standard care groups (17% vs 17%; P =.35). There also was no significant difference in the proportion of patients who required IMV.

In regard to primary and secondary outcomes, results were consistent on analysis of prespecified subgroups stratified by age, sex, race/ethnicity, duration of symptoms prior to treatment allocation, use of corticosteroids, cause-specific mortality, ventilation use, successful cessation of IVM, and receipt of renal dialysis or hemofiltration. Of note, 18 patients in the aspirin group reported a severe adverse effect to aspirin therapy.

This study was limited by the lack of information on radiologic or physiologic outcomes.

The investigators noted that “…the results of this large, randomized trial do not support the addition of aspirin to standard thromboprophylaxis or therapeutic anticoagulation in patients hospitalized with COVID-19.” They concluded that “further studies to identify the safety and efficacy of aspirin in [nonhospitalized] patients with COVID-19 are needed and are ongoing.”


Horby PW, Pessoa-Amorim G, Staplin N, Emberson JR, Campbell M, Spata E, et al, with the RECOVERY Collaborative Group. Aspirin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial. Lancet. Published online November 17, 2021. doi:10.1016/S0140-6736(21)01825-0