If you’ve considered getting a heart scan, like a coronary calcium score, to catch heart disease early, a large new study published in the New England Journal of Medicine suggests the heart itself may not be the earliest place plaque shows up — and that relying on a clean heart scan alone could miss disease that’s already been growing elsewhere in the body for years. (Based on the insights of Dr. Gil Carvalho)
Key Takeaways
- A large NEJM study of ~16,000 symptom-free adults found 57% already had some detectable arterial plaque.
- In people under 40–50, plaque overwhelmingly shows up first in the neck (carotid) or leg (femoral) arteries — not the heart.
- A clean heart scan doesn’t rule out plaque that’s already forming elsewhere and may later progress to the heart.
- Carotid and leg artery ultrasounds can detect this peripheral plaque; they’re generally reserved for people with risk factors or family history, not universal screening.
- The ankle-brachial index (ABI) is a free, at-home test for significant leg-artery blockage, using nothing more than a home blood pressure cuff.
What the Study Found
Researchers scanned the arteries of roughly 16,000 people with no symptoms and no known cardiovascular disease. Overall, 57% already had some detectable plaque — a striking number given that none of these individuals had been diagnosed with heart disease. As expected, this varied heavily by age: even among the youngest group studied, ages 18 to 29, 5 to 10% already had detectable plaque, rising to over 90% by the time people reached their 60s. Plaque was also somewhat more common in men than women across nearly all age groups.
The Surprising Part: Where Plaque Shows Up First
The most notable finding wasn’t just how common plaque was — it was where it tended to appear first. Researchers looked at three areas: the coronary arteries of the heart, the carotid arteries in the neck, and the femoral arteries in the legs.
In the youngest adults (18–29) who had any detectable plaque, it was almost entirely found in the peripheral arteries — the neck or legs — rather than the heart.