CATEGORY: HEART & CIRCULATION
For adults with established coronary artery disease—the heart’s arteries narrowed by plaque—long-term clopidogrel lowered the combined risk of heart attack, stroke, cardiovascular death and related events by 14% compared with daily aspirin, at 2.61 versus 2.99 events per 100 patient-years, with no increase in major bleeding, in a pooled analysis of individual patient records from seven randomized trials totaling 28,982 people published in The Lancet.1
Seven Coin-Flip Trials, Read Patient by Patient
A daily aspirin has been the default lifelong pill for people with coronary artery disease for decades. To test whether it is actually the better choice, researchers gathered the raw, person-by-person records of every randomized trial that had compared clopidogrel alone against aspirin alone in this population—seven trials in all, from the landmark 1990s CAPRIE study to the large Korean HOST-EXAM trial—and reanalyzed them as one dataset. Each of the 28,982 patients had been assigned to one drug or the other by chance, so the two groups started out alike in age, health and habits, and any gap at the end belongs to the drugs. Patients were followed for a median of 2.3 years and for up to five and a half, with heart attacks, strokes, cardiovascular deaths and bleeding episodes recorded and verified in each trial. Results are counted per 100 patient-years, a measure that adds up every participant’s time in the study, so that people followed for one year and for five both count fairly.
Fewer Heart Attacks and Strokes, and No Extra Bleeding
Major cardiovascular or cerebrovascular events—heart attack, stroke, cardiovascular death and related emergencies—occurred 929 times among patients on clopidogrel and 1,062 times among those on aspirin: 2.61 versus 2.99 events per 100 patient-years, a 14% lower risk. The gap was driven by roughly 20% fewer heart attacks and strokes. The main worry with any clot-preventing drug is bleeding, and here the two drugs were even: major bleeding occurred at 0.71 events per 100 patient-years on clopidogrel and 0.77 on aspirin, a difference small enough to be due to chance. One thing did not move: deaths from any cause were the same in both groups over the period studied.
Two Different Doors on the Same Sticky Cell
Both drugs work on platelets—the tiny cell fragments in blood that clump together to plug a damaged vessel wall, and that can also clump inside a narrowed artery and set off a heart attack or stroke. Aspirin and clopidogrel quiet the same cell through two different doors: aspirin blocks one chemical signal that tells platelets to activate, while clopidogrel blocks another, a receptor on the platelet’s surface. A long-noted wrinkle is that some people carry gene variants that slow the body’s conversion of clopidogrel into its active form. In this analysis the advantage held across subgroups, including patients with reduced clopidogrel responsiveness.
A Result That Leans Against a Long-Standing Default
The authors concluded that the findings “support the consideration of clopidogrel as the preferred long-term antiplatelet strategy instead of aspirin” for people with established coronary artery disease. Both medicines are decades old, generic and inexpensive, which makes the comparison unusually practical: this is not a new drug against an old one, but two familiar pills whose head-to-head answer took thirty years of trials to accumulate. The individual trials pooled here had each pointed in the same direction, and combining their patients gave the question its most precise answer yet.
Key Takeaways
- Across seven randomized trials of 28,982 adults with coronary artery disease, clopidogrel lowered the combined rate of heart attack, stroke and other major cardiovascular events by 14% versus daily aspirin—2.61 versus 2.99 events per 100 patient-years.
- The benefit came from fewer heart attacks and strokes; deaths from any cause were the same in both groups.
- Major bleeding, the chief concern with clot-preventing drugs, was no more common on clopidogrel than on aspirin.
- The advantage held even among patients whose genetic makeup slows clopidogrel’s activation.
References
- Valgimigli M, Choi KH, Giacoppo D, et al. Clopidogrel versus aspirin for secondary prevention of coronary artery disease: a systematic review and individual patient data meta-analysis. The Lancet. 2025;406(10508):1091–1102. link