Scanning 16,808 adults with no known heart disease found plaque in more than half

Atherosclerosis is usually described as a disease of later life, because that is when it announces itself. The REACT study, published in the New England Journal of Medicine on 29 August and presented at ESC Congress 2026, went looking for it in people who had no idea they had it — and found it in 57.1% of 16,808 adults with no known atherosclerotic cardiovascular disease [s1].

What the study did

REACT was a prospective cohort study conducted in Denmark and Spain [s1]. Adults aged 18 to 70 with no known atherosclerotic cardiovascular disease were enrolled in five prespecified age strata, each with balanced numbers of women and men [s1]. That stratified, sex-balanced recruitment is the design feature that makes the age and sex comparisons meaningful rather than an artefact of who volunteered.

Silent atherosclerosis was assessed at baseline in two ways: three-dimensional vascular ultrasonography of the carotid and femoral arteries, and coronary computed tomographic angiography [s1]. Imaging three territories rather than one is what allows the study to say where disease starts, not only whether it is present.

A total of 16,808 adults were enrolled, with a mean age of 45 ± 12 years, and 51.4% were women [s1].

What they found

Silent atherosclerosis was present in 57.1% of participants (95% CI 56.3 to 58.0) [s1].

The age gradient is the substance of the result. In the youngest stratum, aged 18 to 29, atherosclerosis was present in 8.7% of the men and 6.7% of the women [s1]. Prevalence rose with age, and the investigators describe the rise among women as later and steeper through midlife [s1] — a pattern consistent with the long-standing observation that women's cardiovascular risk trajectory is offset from men's rather than simply lower.

Two further findings matter more than the headline prevalence.

First, location. Among participants in the younger age strata, atherosclerosis was most often peripheral and confined to a single vascular territory [s1]. With increasing age, plaque volume increased exponentially and multiarterial involvement became more frequent [s1].

Second, the coronary arteries were rarely the only site involved. Isolated coronary-artery atherosclerosis was uncommon in every age stratum, at no more than 9.3% of men and no more than 5.0% of women [s1].

Why that last number is the interesting one

Cardiovascular screening, when it happens at all, tends to look at the heart — a coronary calcium score or a coronary CT. REACT's finding is that in adults without known disease, the coronary arteries are usually not where the disease shows up first, and almost never the only place it is [s1].

That is consistent with earlier imaging cohorts. The PESA study, which scanned 4,184 asymptomatic people aged 40 to 54 in Spain a decade ago, found subclinical atherosclerosis in 63% of participants, with plaques most common in the iliofemoral arteries (44%), then the carotids (31%) and aorta (25%), while coronary artery calcification was present in 18% [s2].

REACT and PESA are not directly comparable — different age ranges, different countries, different imaging protocols and different definitions of disease — so the prevalence figures should not be set against each other as though they measured the same thing. What they agree on is the ordering: peripheral arteries first, coronary arteries later and less often in isolation.

What this does not mean

REACT is a prevalence study. It reports how common silent atherosclerosis is, where it sits and how much of it there is — not what happens to the people who have it, and not whether finding it improves anyone's outcome.

The distinction matters because the obvious inference from a 57.1% prevalence is that everyone should be scanned, and this study cannot support that inference [s1]. Detecting plaque in an asymptomatic 25-year-old is only useful if it changes management in a way that changes their life, and REACT did not test any management strategy. The background evidence the authors cite is that silent atherosclerosis is associated with cardiovascular events and death independently of traditional risk factors [s1]; association is not the same as a demonstrated benefit from screening.

There are also population limits. The cohort was recruited in Denmark and Spain [s1], and prevalence of atherosclerosis varies substantially between populations with different risk-factor profiles. The figures here should not be read as global.

The study was funded by the Novo Nordisk Foundation and registered as NCT06692127 [s1].

What to watch

REACT is prospective, so the question that follows is what happens over follow-up: whether the plaque found in the youngest strata progresses, in whom, and how strongly baseline plaque volume predicts events beyond conventional risk scores. The authors' own framing — that plaque volume increased exponentially with age — suggests volume, rather than a yes-or-no plaque finding, is where the predictive signal is likely to sit [s1].

The second thing to watch is whether guideline bodies treat peripheral imaging differently in light of this. If the disease is mostly femoral and carotid in early adult life, a screening approach built around the coronary arteries is looking in the wrong place [s1].

This article describes research findings. It is not medical advice, and nothing here should be used to decide whether to seek or avoid any test.