In order to bring you the best possible user experience, this site uses Javascript. If you are seeing this message, it is likely that the Javascript option in your browser is disabled. For optimal viewing of this site, please ensure that Javascript is enabled for your browser.
Did you know that your browser is out of date? To get the best experience using our website we recommend that you upgrade to a newer version. Learn more.

COVID-19 patients in the community do not benefit from colchicine or aspirin

ACT Outpatient Trial presented in a Hot Line Session today at ESC Congress 2022

Pharmacology and Pharmacotherapy

Barcelona, Spain – 29 Aug 2022: A randomised trial in nearly 4,000 outpatients with COVID-19 has found no benefit of treatment with aspirin or colchicine. The late breaking research is presented in a Hot Line session today at ESC Congress 2022.1

Principal investigator Dr. John Eikelboom of McMaster University, Hamilton, Canada said: “The results provide no evidence that colchicine or aspirin are beneficial in outpatients with COVID-19. Vaccination remains the most effective treatment to reduce hospitalisation and death due to COVID-19.”

In December 2021 it was estimated that 3.8 billion persons worldwide had been infected with the SARS-CoV-2 virus that causes COVID-19.2 While only a minority of those infected develop moderate or severe disease, the large number of patients requiring hospitalisation has overwhelmed many healthcare systems. Additional affordable and efficacious therapies are needed to prevent disease progression.

Worsening disease in patients with COVID-19 is characterised by a dysregulated inflammatory response and haemostatic activation.3,4 The Anti-Coronavirus Therapies (ACT) Outpatient Trial tested two treatments: colchicine to target inflammation and aspirin to target haemostatic activation, with the goal of preventing disease progression in community-based patients with COVID-19. The trial was conducted in 12 countries.

The trial randomised 3,917 community-based patients with laboratory-diagnosed COVID-19 to receive 28 days of treatment with: (1) colchicine (0.6 mg twice daily for three days, followed by 0.6 mg once daily for an additional 25 days) versus control and (2) aspirin (100 mg once daily) versus control, using a factorial design.5 The design enabled simultaneous evaluation of the independent effects of colchicine and of aspirin as well as their possible additive effects. The main outcome for the comparison between colchicine and control was hospitalisation or death, and for the comparison between aspirin and control was major thrombosis, hospitalisation, or death.

Colchicine compared with control did not significantly reduce hospitalisation or death (66 [3.4%] vs. 65 [3.3%] events, hazard ratio [HR] 1.02, 95% confidence interval [CI] 0.72–1.43, p=0.926). Aspirin versus control did not significantly reduce major thrombosis, hospitalisation, or death (59 [3.0%] vs. 73 [3.8%] events, HR 0.80, 95% CI 0.57–1.13, p=0.211). There was no evidence of benefit of either treatment in any of the subgroups examined, including severity of disease at baseline, time from diagnosis to randomisation, vaccination status, or time of treatment according to the phase of the pandemic.

The authors noted that event rates in the control group fell progressively during the course of the study from around 7–8% at the beginning to less than 2% towards the end, and the number of patients who experienced an outcome was substantially lower than expected.

The researchers also performed an updated meta-analysis of randomised trials of colchicine in outpatients (n=8,369) and inpatients (n=15,335) with COVID-19 which provided no evidence of a significant benefit, either for the prevention of the primary outcome (as reported in the trials) or for the prevention of mortality

Dr. Eikelboom said: “Several factors may have contributed to the falling event rates over time, including changing virulence of different strains of the SARS-CoV-2 virus, increasing population immunity conferred by a combination of herd immunity and immunisation, increasing use of effective cointerventions in more vulnerable populations, or changing patterns of disease management.” 

He concluded: “Taken together with the results of our updated meta-analysis, the evidence from the ACT Outpatient Trial does not support the use of either colchicine or aspirin for the treatment of outpatients with COVID-19. Patients with COVID-19 who are currently infected and at risk of disease progression might consider the use of proven effective antiviral therapies, if accessible, to prevent disease progression.”



Notes to editor

ESC Press Office
Tel: +33 (0) 7 8531 2036

Follow us on Twitter @ESCardioNews 

The hashtag for ESC Congress 2022 is #ESCCongress.


This press release accompanies both a presentation and an ESC press conference at ESC Congress 2022. It does not necessarily reflect the opinion of the European Society of Cardiology.


Funding: The study was funded by the Canadian Institutes for Health Research, the Thistledown Foundation, and Bayer AG who also provided in-kind support. None of the funders had a role in design, conduct, analysis, interpretation or reporting of the results.


Disclosures: JE has received honoraria and research support from Bayer AG.


References and notes

1ACT Outpatient Trial will be discussed during Hot Line Session 10 on Monday 29 August at 16:30 to 17:30 CEST in the Barcelona auditorium.

2COVID-19 Cumulative Infection Collaborators. Estimating global, regional, and national daily and cumulative infections with SARS-CoV-2 through Nov 14, 2021: a statistical analysis. Lancet. 2022;399:2351–2380.

3Bonaventura A, Vecchie A, Dagna L, et al. Colchicine for COVID-19: targeting NLRP3 inflammasome to blunt hyperinflammation. Inflamm Res. 2022;71:293–307.

4Leentjens J, van Haaps TF, Wessels PF, et al. COVID-19-associated coagulopathy and antithrombotic agents-lessons after 1 year. Lancet Haematol. 2021;8:e524–e533.

5Eikelboom J, Rangarajan S, Jolly SS, et al. The Anti-Coronavirus Therapies (ACT) trials: design, baseline characteristics, and challenges. CJC Open. 2022;4:568–576.


About the European Society of Cardiology

The ESC brings together health care professionals from more than 150 countries, working to advance cardiovascular medicine and help people to live longer, healthier lives.

About ESC Congress 2022

It is the world’s largest gathering of cardiovascular professionals, disseminating ground-breaking science both onsite in Barcelona and online – from 26 to 29 August. Explore the scientific programme. More information is available from the ESC Press Office at