Aspirin is one of the most widely taken medicines in the world, having been recommended for decades as a way of protecting against heart attacks and strokes in at-risk patients. However, a new study has revealed that clopidogrel, another commonly used blood thinner, or anticoagulant, is more effective in preventing serious heart attacks and strokes and carries no additional risk.
The finding is the result of research conducted by an international team of scientists from the US, UK, Switzerland, Australia, and Japan. Their work is a meta-analysis—a study that collects and analyzes the results of multiple smaller studies, with the aim of reaching a more reliable conclusion by looking at a larger amount of data. In total, this meta-analysis looked at clinical data from nearly 29,000 patients diagnosed with coronary artery disease (CAD), a condition where fat builds up in the arteries, which can lead to secondary effects such as heart attacks and heart failure.
The specialists conducted a systematic search of medical databases such as PubMed, Scopus, Web of Science, and Embase to find randomized trials of treatments for CAD published up to April 12, 2025. The aim was to identify papers comparing the efficacy of aspirin versus clopidogrel in the prevention of cardiovascular deaths, heart attacks, and strokes.
The analysis focused on seven investigations that included clinical information from persons with confirmed cases of CAD treated with aspirin or clopidogrel for an average of 2.3 years. After a follow-up of 5.5 years, the researchers observed that those who received clopidogrel had a 14 percent lower risk of a major cardiovascular event compared with those treated with aspirin.
Ultimately, the team concluded that these findings “add to the evidence” that clopidogrel is superior to aspirin for preventing major adverse cardiac and cerebrovascular events. In the researchers’ view, these findings support using clopidogrel over aspirin in patients with established CAD to try to prevent them going on to have major complications as a result of their condition, such as a heart attack. The findings were published in the journal The Lancet.
In terms of mortality and bleeding risk, the meta-analysis concluded that the rates were similar in both groups, confirming that clopidogrel is as safe as aspirin.
“To the best of our knowledge, clopidogrel monotherapy is the only antiplatelet treatment that has consistently demonstrated greater efficacy than aspirin without compromising safety,” the researchers wrote in the paper.
The discovery could transform medical guidelines internationally. Clopidogrel is a widely available, affordable drug with reliable generic versions, characteristics that would make it easy to incorporate into routine clinical practice. Nevertheless, specialists stress that more extensive research is needed to evaluate the cost-effectiveness of clopidogrel and its performance in diverse populations in order to support its inclusion in treatment standards.
Cardiovascular diseases are the leading cause of death in the world. According to the World Health Organization, an estimated 17.9 million people die each year from these conditions. More than four out of every five of these deaths are due to coronary heart disease or stroke. The new research suggests that clopidogrel could become a key alternative to combat this public health problem, the incidence of which continues to rise around the world.
This story originally appeared on WIRED en Español and has been translated from Spanish.
