Low-dose aspirin is downgraded to prevent cardiovascular disease


A recent article published in the Journal of the American Medical Association (JAMA) analyzed the use of aspirin to prevent cardiovascular disease (CVD) and colorectal cancer (CRC).

Report: Using Aspirin to Prevent Cardiovascular Disease and Colorectal Cancer Evidence Report Update and Systematic Review for the US Preventive Services Task Force. Image Credit: Evgenyrychko/Shutterstock


Cardiovascular disease is the leading cause of death in the United States (US). Existing reports indicate that low-dose aspirin used to prevent primary cardiovascular disease may also help prevent CRC.

The US Preventive Services Task Force (USPSTF) announced in 2016 guidelines on the use of aspirin based on cardiovascular risk and age for the prevention of CRC and CVD.

About the study

In this systematic review, researchers analyzed the existing evidence for the harms and benefits of aspirin in CRC and primary CVD prevention to update the USPSTF. In addition, the team assessed the Cochrane Central Register of Controlled Trials from January 2021 and searched the literature from 21 January 2022. The primary outcomes of this survey were colorectal cancer incidence and death , severe bleeding, hemorrhagic stroke, cardiovascular events. and fatality, and every cause of death.

The authors selected randomized clinical trials (RCTs) of low-dose aspirin (100 mg/day) versus placebo or no treatment in English-language primary prevention populations for review. Data were extracted via a single extraction and double-checked by a second reviewer. Additionally, Peto’s fixed-effects meta-analysis was used for quantitative synthesis. Eleven RCTs including 134,470 studies and one pilot trial with 400 investigations of low-dose aspirin treatment for primary CVD prevention were included in this search.

Mantel-Haenszel fixed effects and limited maximum likelihood random effects models were used to perform sensitivity analysis. Trials addressing secondary CVD prevention and all doses of aspirin were included in sensitivity analyzes for the CCR outcomes. These analyzes looked at different indications and doses of aspirin encompassing comprehensive post-trial observational data.

Findings and discussions

Study results indicated that low-dose aspirin use was linked to significantly reduced risk of CV events such as total myocardial infarction (MI), ischemic stroke, and cardiovascular events. majors. Individualized cardiovascular outcomes were substantial, with benefit of a similar size. Interestingly, the team reported that aspirin has not been shown to be drastically linked to a lower risk of CVD or death from all causes up to 10 years of follow-up.

The authors found that the benefits of low-dose aspirin treatment for CRC were inconclusive in clinical trials. Moreover, the results were highly variable depending on the length of follow-up and statistically relevant only when long-term observational follow-up beyond randomized trial periods was taken into account.

Current data indicated that low-dose aspirin was linked to substantial increases in major and site-specific overall bleeding, including extracranial and intracranial hemorrhage, both of comparable size. Unfortunately, the authors could not determine how enteric coating of aspirin or dosage modifications may reduce bleeding risk due to insufficient data in current investigations of primary CVD prevention. Yet, existing observational research has demonstrated that high doses of aspirin are linked to an increased risk of bleeding.

The results of sensitivity analyzes conducted in this review revealed discrepancies in results between RCTs performed before and after the publication of the Adult Treatment Panel III (ATP III) guideline in 2001. According to the sensitivity analyses, benefits of MI, major cardiovascular events, and most bleeding risks were reduced in post-ATP III trials, while ischemic stroke emerged as a statistically relevant benefit in post-ATP III pooled analyzes . These results were consistent with a previous study comparing pre-ATP III and post-ATP III assays. However, the scientists said additional sources of variability, such as aspirin dosage and characteristics of the test population, were likely to impact these results.

Additionally, although benefits are expected to diminish over time as aspirin use converges, sensitivity analyzes to CRC results revealed positive effects of aspirin use. aspirin on the incidence of CRC up to about 20 years.


Overall, the current results showed that low-dose aspirin was associated with minor reductions in the absolute risk of major CV events and small elevations in the absolute risk of major bleeding. Results for CRC were less consistent and significantly variable.

The results of the present meta-analysis were similar to those of the previous USPSTF systematic review and many other recent meta-analyses, revealing that small absolute reductions in the incidence of aspirin-induced CVD were closely reflected in increases in major bleeding. The authors recommended that a comprehensive low-dose aspirin study evaluating the effects of CRC 20 years after randomization would be appropriate to investigate the marginal impacts of aspirin use in the current context of CRC screening techniques. CCR. In addition, future studies should cover baseline CRC assessment and CRC risk variables, which are possible confounders that have not been addressed in the majority of CVD prevention trials included in this review. .

Journal reference:

  • Guirguis-Blake JM, Evans CV, Perdue LA, Bean SI, Senger CA. Use of aspirin to prevent cardiovascular disease and colorectal cancer: updated evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2022;327(16):1585–1597, DOI:10.1001/jama.2022.3337, https://jamanetwork.com/journals/jama/fullarticle/2791401

Comments are closed.