Silent atherosclerosis was already detectable in some adults in their 20s, according to the REACT study published in The New England Journal of Medicine. The study imaged 16,808 adults aged 18 to 70 in Denmark and Spain who had no known atherosclerotic cardiovascular disease and found plaque in 57.1% overall, including 8.7% of men and 6.7% of women aged 18 to 29.
REACT looked for plaque directly rather than estimating future risk
Atherosclerosis is the buildup of plaque within artery walls. It can remain clinically silent for years before contributing to coronary artery disease, peripheral artery disease, heart attack or ischemic stroke. Most preventive care therefore begins before symptoms appear, using factors such as age, smoking, blood pressure, cholesterol and diabetes to estimate future cardiovascular risk.
REACT took a different approach. Rather than asking only who was likely to develop cardiovascular disease later, investigators looked for existing plaque across several parts of the arterial system.
Participants underwent three-dimensional vascular ultrasound of the carotid arteries in the neck and femoral arteries in the legs. The coronary arteries were assessed with coronary computed tomographic angiography. The cohort was divided into five prespecified age groups from 18 through 70 years, with approximately balanced numbers of women and men.
The mean age was 45 years, and 51.4% of participants were women. None had a known history of atherosclerotic cardiovascular disease when they entered the study.
About 1 in 13 adults under 30 already had detectable plaque
The headline result was the overall prevalence: 57.1% of participants had silent atherosclerosis in at least one of the vascular territories examined.
The youngest group makes the finding more striking. Among adults aged 18 to 29, plaque was detected in 8.7% of men and 6.7% of women. Combined, that is roughly 1 in 13 people in an age group that would generally be expected to have very low short-term cardiovascular event risk.
This does not mean that 1 in 13 people in their 20s is close to having a heart attack. The study measured the presence of plaque, not near-term clinical events. A small, early plaque and advanced obstructive disease are not equivalent.
What the result does show is that the biological process of atherosclerosis can be visible well before cardiovascular disease becomes clinically apparent. That distinction matters because atherosclerosis is a long-running process, whereas heart attack and stroke are later clinical outcomes. Our earlier coverage of heart attack and stroke risk also illustrates that the final event depends on more than plaque presence alone, including thrombosis and other vascular factors.
Early plaque was usually peripheral and limited to one arterial territory
Where the plaque appeared also changed with age. In the younger age groups, atherosclerosis was most often found in peripheral arteries and was usually confined to a single vascular territory rather than appearing throughout the arterial system.
Isolated coronary atherosclerosis was uncommon across all age groups. According to the NEJM report, coronary plaque without plaque in the carotid or femoral arteries occurred in no more than 9.3% of men and 5.0% of women in any age stratum.
With increasing age, the pattern became more extensive. Plaque volume rose markedly, and involvement of multiple arterial territories became more common. The researchers described plaque volume as increasing exponentially with age.
This supports the idea that atherosclerosis is systemic rather than a condition confined to the heart. A person may develop measurable disease in arteries outside the heart before coronary disease becomes the dominant clinical concern.
Men showed an earlier rise, while women had a steeper increase in midlife
The age pattern differed between women and men. Men developed a higher prevalence of detectable atherosclerosis earlier in adulthood. Women showed a later but particularly steep rise in midlife, narrowing some of the sex difference at older ages.
The timing overlapped with the typical menopausal transition, but REACT was not designed to prove that menopause caused the acceleration. Age, hormonal changes and shifts in other cardiovascular risk factors may all contribute. The finding nevertheless fits a broader body of research examining cardiovascular risk around perimenopause and menopause.
By ages 60 to 70, the European Society of Cardiology reported that roughly 9 in 10 participants had detectable atherosclerosis. The important pattern was not simply that prevalence rose with age, but that plaque burden and the number of affected vascular territories also increased.
Risk scores and imaging answer different questions
One of the more provocative parts of REACT was the comparison with conventional cardiovascular risk estimation.
Risk calculators such as SCORE2 estimate the probability of a cardiovascular event over a defined period using clinical risk factors. They are not designed to determine whether plaque is already present. REACT found that only a small minority of participants with imaging-detected atherosclerosis were classified as high risk by SCORE2, particularly at younger ages.
That discordance should not be interpreted to mean that established risk calculators have failed. A 30-year-old with a small plaque can have both existing atherosclerosis and a low probability of a heart attack or stroke over the next 10 years. Those are different measurements.
The study instead raises a prevention question: could identifying plaque directly help clinicians distinguish which people with apparently low short-term risk would benefit from earlier or more intensive risk-factor treatment?
That question is especially relevant to cholesterol management, where treatment decisions are commonly guided by overall cardiovascular risk as well as low-density lipoprotein cholesterol levels. We have previously covered how treatment decisions can change with age in the context of statin therapy in older adults. REACT asks almost the opposite question: whether visible disease could eventually justify acting earlier.
The study does not establish a new screening recommendation
REACT is a large and unusually detailed imaging study, but its current results are primarily a prevalence map. They show how often plaque was detectable across age and sex groups at baseline.
They do not show that screening asymptomatic young adults with vascular ultrasound or coronary computed tomographic angiography prevents heart attacks, strokes or deaths. Imaging can also identify abnormalities whose clinical importance is uncertain, and coronary CT involves considerations such as radiation exposure, contrast administration, cost and follow-up testing.
The study was conducted in Denmark and Spain, so the exact prevalence estimates may not apply to populations with different genetic backgrounds, healthcare systems, smoking patterns, diets or cardiometabolic risk profiles.
It is also important that these are cross-sectional baseline findings. The age pattern is consistent with atherosclerosis accumulating over adult life, but the investigators did not follow the same people from their 20s into their 60s to derive the prevalence curve reported here.
The next question is whether finding plaque earlier changes outcomes
The REACT investigators have framed the current work as the detection phase of a larger research program. A planned randomized second phase is intended to test whether prevention guided by early vascular imaging can improve how atherosclerosis is managed compared with conventional risk-based strategies.
That is the experiment needed before the current findings can become a broad screening strategy.
For now, the study changes the picture of when atherosclerosis is present more than it changes clinical practice. Plaque was measurable in a meaningful minority of adults before age 30, became progressively more common and more extensive with age, and often existed in people who would not be considered at high short-term cardiovascular risk.
References
- Bundgaard H, García-Lunar I, Kofoed KF, et al. Prevalence of Silent Atherosclerosis across Adult Life. New England Journal of Medicine. Published August 29, 2026. DOI: 10.1056/NEJMoa2609059.
- European Society of Cardiology. Early imaging of atherosclerosis identifies silent disease not captured by conventional risk assessment. August 29, 2026. ESC research summary.
- ClinicalTrials.gov. DETECTion of the Prevalence of Silent Atherosclerosis Across Adult Life – Phase I of REACT. NCT06692127. ClinicalTrials.gov record.
- Ibanez B, Bundgaard H, et al. Prevalence and predictors of silent atherosclerosis across life: Design of the REACT Phase 1 study. American Journal of Preventive Cardiology. 2026;101726. DOI: 10.1016/j.ajpc.2026.101726.