How Carotid Plaque Is Actually Evaluated and Treated

From Doppler ultrasound to CREST-2 — what your carotid stenosis result really means, how doctors assess stroke risk, and why a severe narrowing doesn't always mean surgery.

ARTERIAL HEALTH — CLINICAL DEEP DIVE

Dr. Daniel Mendonça

8/18/20268 min read

In short: Finding plaque or narrowing in your carotid artery can be frightening, especially when your ultrasound report mentions 70% or more. But that number alone cannot tell you whether you're likely to have a stroke or whether you need surgery. What matters most is whether you've experienced warning symptoms, how severe the narrowing is, and how much benefit a procedure would add to modern medical treatment. The landmark CREST-2 trial has brought new evidence to this decision — and challenged the idea that every severe carotid narrowing should automatically be treated with surgery.

How the Diagnosis Actually Happens

If your ultrasound report mentions carotid plaque, the first thing to understand is that having plaque doesn't necessarily mean your artery is dangerously blocked.

Plaque is a buildup of fatty and inflammatory material inside the artery wall. When that buildup narrows the opening through which blood flows, doctors call it carotid stenosis.

The usual first test is carotid duplex ultrasound, also called Doppler ultrasound. It uses sound waves to show the artery and measure how quickly blood flows through it. Faster flow through a narrowed segment helps doctors estimate the degree of stenosis.

But there's a detail many patients never hear: the percentage on your report is an estimate, not a perfectly precise measurement. Different measurement methods, such as NASCET and ECST, can produce different percentages for the same artery.

If the result is unclear or a procedure is being considered, CT angiography or MR angiography — scans that provide more detailed pictures of the blood vessels — may help confirm the findings.

A reported 70% narrowing is important. But it is the beginning of a clinical decision, not the decision itself.

Does a 70% Narrowing Mean You're Going to Have a Stroke?

Not necessarily.

Two people can have the same degree of carotid narrowing and face very different risks.

The biggest distinction is whether you've already experienced symptoms caused by that artery.

If you've recently had a transient ischemic attack (TIA, sometimes called a mini-stroke), a stroke, or sudden temporary blindness in one eye related to the affected carotid, your risk of another event may be significantly higher.

If the narrowing was found during an examination and you've never experienced related symptoms, the situation is different. Doctors call this asymptomatic carotid stenosis.

Researchers have also discovered that the plaque itself may contain clues about future risk.

In the ACSRS study, certain ultrasound features of plaques helped predict stroke risk more accurately than the narrowing percentage alone. The ACES study found that patients with tiny embolic signals — signs that small particles may be traveling toward the brain — had a higher risk of subsequent stroke.

These findings help explain why the same percentage doesn't always mean the same danger.

However, these specialized tests and measurements aren't routinely used for every patient, and no single plaque feature can reliably predict exactly what will happen to you.

If you suddenly develop facial drooping, weakness on one side, difficulty speaking, or loss of vision, seek emergency medical care immediately — even if the symptoms disappear.

The Foundation: Treating the Disease, Not Just the Narrowing

A carotid plaque is not an isolated problem. It is a sign of atherosclerosis, a disease that can also affect arteries supplying your heart, legs, and other organs.

That's why treatment isn't just about opening one narrowed artery.

Controlling cholesterol, blood pressure, diabetes, and smoking can reduce the risk of serious cardiovascular events. Statins are particularly important for many patients because they lower cholesterol and help reduce the risks associated with atherosclerotic disease.

Antiplatelet medications, which reduce the tendency of platelets to form blood clots, may also be recommended depending on your symptoms, degree of stenosis, and overall medical situation.

This approach is called best medical therapy or intensive medical management.

It is not simply what doctors offer when surgery isn't possible. It is an essential part of treatment, whether or not you eventually undergo a procedure.

When Surgery Really Makes a Difference

If you've recently had a TIA or minor stroke caused by a significantly narrowed carotid artery, removing the plaque can prevent another stroke.

The strongest evidence for carotid endarterectomy — an operation that opens the artery and removes the plaque — is in appropriately selected patients with recent symptoms and severe narrowing, usually 70–99%.

Some patients with symptomatic narrowing of 50–69% may also benefit, depending on their individual circumstances.

Timing matters. When surgery is appropriate after a TIA or nondisabling stroke, doctors often aim to perform it within two weeks, because the risk of another event can be highest early on.

But what if you've never had symptoms?

That's where the decision becomes less straightforward.

For years, studies supported preventive surgery in selected patients with severe asymptomatic narrowing. Yet those studies were conducted when cholesterol treatment and cardiovascular prevention were less effective than they are today.

As medical treatment improved, an important question emerged: does a procedure still prevent enough additional strokes to justify its immediate risks?

CREST-2: The Trial That Changed the Conversation

CREST-2, first published online in November 2025, investigated that question in patients with severe carotid narrowing of at least 70% who had not experienced recent related neurological symptoms.

The researchers conducted two separate trials involving nearly 2,500 participants.

One compared intensive medical treatment alone with the same treatment plus carotid stenting — placing a small metal mesh tube inside the artery to keep it open.

The other compared intensive medical treatment alone with the same treatment plus carotid endarterectomy.

The results were revealing.

In the stenting trial, over four years:

About 6 in every 100 patients receiving intensive medical treatment alone experienced the study's primary outcome.
About 3 in every 100 patients receiving stenting plus medical treatment experienced that outcome.

The measured rates were 6.0% and 2.8%, respectively — an absolute reduction of 3.2 percentage points, or approximately 53% in relative terms.

That difference was statistically significant, meaning the evidence supported a genuine treatment effect rather than an apparent difference readily explained by chance.

In the surgery trial, the corresponding rates were 5.3% with medical treatment alone and 3.7% with endarterectomy plus medical treatment — an absolute difference of 1.6 percentage points.

This difference was not statistically significant.

There are three essential details behind these numbers.

First, the study measured a combination of outcomes: any stroke or death during the initial 44 days, followed by ischemic stroke on the same side as the affected artery during the remainder of the four-year follow-up. These percentages should not be described simply as the risk of any stroke over four years.

Second, the two procedures were tested in separate trials. CREST-2 did not establish that stenting is superior to surgery.

Third, failing to demonstrate a statistically significant surgical benefit does not prove that surgery can never help.

The important message is more practical: modern medical treatment produced relatively low event rates, and the additional benefit of a procedure must be carefully weighed against its immediate risks.

For someone with severe asymptomatic stenosis, the decision is no longer as simple as looking at a percentage and recommending an operation.

Why Two Specialists May Recommend Different Treatments

You might receive a recommendation for surgery from one specialist and a recommendation for continued medical treatment from another.

That doesn't automatically mean one of them is wrong.

The Society for Vascular Surgery has supported endarterectomy in selected patients with severe asymptomatic narrowing and low procedural risk.

The European Society for Vascular Surgery takes a more selective approach, emphasizing additional signs of increased stroke risk, sufficient life expectancy, and a low expected complication rate.

Both sets of guidelines were published before the CREST-2 results became available.

Newer research, including ECST-2, has added to the discussion about which patients truly benefit from intervention.

Your age, symptoms, artery anatomy, other medical conditions, and the experience of the treating team all influence the decision.

The question isn't simply whether a narrowing can be treated. It's whether treating it with a procedure offers you more protection than medical therapy alone.

Stenting or Endarterectomy: Which Is Better?

If you do need an intervention, there are two established approaches.

Carotid endarterectomy removes the plaque through an operation on the artery.

Carotid stenting uses a catheter to position a stent inside the narrowed segment, without surgically removing the plaque.

Neither approach is automatically better for everyone.

The original CREST trial found broadly similar overall results for its combined primary outcome, but the balance of risks varied with age. Older patients generally had more favorable outcomes with surgery than with stenting performed through an artery in the groin, particularly regarding the risk of stroke around the time of the procedure.

ACST-2 also found similar long-term rates of disabling or fatal stroke in selected asymptomatic patients undergoing either procedure, although some early procedural risks differed.

The best choice depends on the artery's anatomy, plaque characteristics, your medical history, and the expertise of the team performing the procedure.

A less invasive procedure is not necessarily the safer or more effective one for every patient.

What the Evidence Shows

The evidence for carotid treatment has evolved considerably.

Trials such as NASCET established the important role of endarterectomy in patients with symptomatic significant stenosis.

ACAS and ACST-1 demonstrated that preventive surgery could reduce stroke risk in selected asymptomatic patients, although their medical-treatment strategies reflected an earlier era.

More recent trials have asked a different question: how much additional protection does intervention provide when patients already receive effective modern medical treatment?

CREST-2 offers one of the clearest answers so far. In selected asymptomatic patients, adding stenting reduced the trial's primary outcome, while adding endarterectomy did not demonstrate a statistically significant benefit over intensive medical treatment alone.

These findings don't eliminate the role of carotid procedures. They make careful patient selection even more important.

The strongest conclusion is that the presence of severe stenosis and the need for intervention are not the same thing.

Vascular Surgeon's Take

One of the most important things to understand about a carotid ultrasound is that a percentage describes the artery, but it doesn't describe your entire stroke risk.

If your report shows severe narrowing, it deserves proper evaluation. But the next question shouldn't automatically be when to schedule surgery.

It should be whether you've experienced symptoms related to that artery, what your risk looks like with modern medical treatment, and how much additional protection a procedure could realistically offer.

For patients with recent symptoms, timely treatment can make a major difference. For those without symptoms, the decision often requires a more careful balance between long-term benefit and immediate procedural risk.

The goal isn't to treat the most alarming number on the report. It's to prevent a stroke with the safest and most effective strategy for your individual situation.