Carotid Artery Disease: Plaque, Stenosis, Stroke Risk, and Treatment

What Are the Carotid Arteries?

The carotid arteries are major blood vessels located on both sides of the neck. They supply blood to the brain and other structures of the head and neck.

Each common carotid artery divides into:

• Internal carotid artery: Supplies an important part of the brain's anterior circulation.
• External carotid artery: Supplies parts of the face, scalp, and neck.

Atherosclerotic plaques may develop in the carotid arteries, causing narrowing of the vessel.

Plaque fragments or blood clots may travel to the brain and cause a transient ischemic attack or ischemic stroke.

What Is Carotid Artery Disease?

Carotid artery disease is characterized by atherosclerotic plaque formation within the carotid arteries.

Atherosclerosis is a chronic process involving the accumulation of cholesterol-containing particles, inflammatory cells, and fibrous tissue in arterial walls.

The presence of carotid plaque does not necessarily mean that significant carotid stenosis is present.

A small plaque may cause little or no narrowing.

More advanced disease may significantly reduce the vessel lumen or become a source of embolism.

What Causes Carotid Artery Disease?

Major risk factors include:

• Elevated LDL cholesterol
• Hypertension
• Smoking
• Diabetes
• Increasing age
• Family history of premature vascular disease
• Chronic kidney disease
• Physical inactivity
• Obesity and metabolic risk factors

Carotid plaque is also a marker of systemic atherosclerosis and should prompt assessment of overall cardiovascular risk.

What Are the Symptoms of Carotid Artery Disease?

Carotid artery disease may remain asymptomatic for many years.

Even severe stenosis may cause no symptoms.

When symptoms occur, they usually result from reduced cerebral blood flow or embolization.

Warning signs include:

• Sudden facial drooping
• Sudden weakness of an arm or leg
• Sudden numbness on one side of the body
• Difficulty speaking
• Sudden difficulty understanding speech
• Temporary loss of vision in one eye
• Other sudden focal neurological symptoms

These symptoms require urgent medical assessment even if they resolve within minutes.

What Is a Transient Ischemic Attack (TIA)?

A transient ischemic attack is a temporary episode of neurological dysfunction caused by focal brain or retinal ischemia without evidence of acute infarction.

Symptoms may disappear completely.

However, a TIA can be an important warning sign of a future ischemic stroke.

Early diagnosis and treatment are particularly important in patients with symptomatic carotid stenosis.

What Is the Difference Between Carotid Plaque and Carotid Stenosis?

Plaque indicates the presence of atherosclerotic disease within the artery.

However, not every plaque causes clinically significant narrowing.

Carotid stenosis is commonly classified as follows:

• Degree of stenosis | General classification |
  |---|---|
  | Less than 50% | Mild |
  | 50–69% | Moderate |
  | 70–99% | Severe |
  | 100% | Complete occlusion |

These categories generally refer to standardized measurements of internal carotid artery stenosis.

Treatment decisions depend not only on the degree of narrowing but also on whether the patient has experienced stroke or TIA.

Are All Carotid Plaques Equally Dangerous?

No.

Carotid plaques differ in composition and morphology.

Some are heavily calcified, while others may contain lipid-rich components or have irregular surfaces.

Risk assessment considers:

• Degree of stenosis
• Plaque ulceration
• Intraplaque hemorrhage
• Plaque morphology
• Previous neurological symptoms
• Associated vascular disease

Even non-obstructive plaque may be important for cardiovascular risk assessment.

However, a small plaque alone does not justify carotid stenting or surgery.

How Is Carotid Artery Disease Diagnosed?

1. Carotid Doppler Ultrasound

Carotid Doppler ultrasound is a widely used, noninvasive imaging method.

It evaluates:

• Presence of plaque
• Plaque location
• Degree of stenosis
• Blood flow velocities
• Hemodynamic characteristics

What Do Doppler Flow Velocities Mean?

Blood flow velocity may increase through a narrowed arterial segment.

However, stenosis severity should not be determined using a single velocity measurement alone.

Peak systolic velocity, end-diastolic velocity, internal-to-common carotid velocity ratio, and anatomical imaging findings should be interpreted together.

Validated laboratory-specific criteria should be used.

2. CT Angiography

CT angiography provides detailed imaging of the cervical and intracranial arteries.

It may be used when intervention is being considered or ultrasound findings are inconclusive.

3. MR Angiography

MR angiography is another option for evaluating carotid artery anatomy.

4. Catheter Angiography

Catheter angiography is invasive and is not routinely required for diagnosis in every patient.

It may be appropriate in selected complex cases or during intervention planning.

Is Cholesterol-Lowering Medication Necessary When Carotid Plaque Is Present?

The detection of atherosclerotic carotid plaque should prompt assessment of the need for lipid-lowering therapy.

Statins lower LDL cholesterol and reduce the risk of cardiovascular events.

However, a small carotid plaque does not automatically mean that every patient requires lifelong statin treatment.

Treatment decisions should consider:

• Age
• LDL cholesterol level
• Plaque burden and characteristics
• Diabetes and hypertension
• Smoking
• Coronary artery disease or previous stroke
• Overall cardiovascular risk

Patients with significant atherosclerotic carotid stenosis or previous atherosclerotic ischemic stroke frequently require intensive lipid-lowering therapy.

Should Patients with Carotid Plaque Take Aspirin?

Aspirin and other antiplatelet medications may be used in appropriate patients to reduce thrombotic vascular events.

Antiplatelet therapy is particularly important after certain types of ischemic stroke or TIA.

However, aspirin is not routinely indicated for every person with a small, asymptomatic carotid plaque.

The potential benefit must be balanced against bleeding risk.

How Is Carotid Artery Disease Treated?

Treatment involves three main approaches.

1. Medical Treatment and Risk Factor Management

Medical management is essential for patients with carotid atherosclerosis.

It includes:

• LDL cholesterol reduction
• Blood pressure control
• Diabetes management
• Smoking cessation
• Antiplatelet therapy when indicated
• Regular physical activity
• Healthy nutrition

2. Carotid Endarterectomy

Carotid endarterectomy is a surgical procedure that removes atherosclerotic plaque from the carotid artery.

It is an important treatment for appropriately selected patients, particularly those with severe symptomatic stenosis.

3. Carotid Artery Stenting

Carotid artery stenting is a catheter-based procedure used to widen a narrowed artery and implant a stent.

It may be an alternative to surgery in selected patients.

When Is Carotid Endarterectomy Recommended?

Carotid endarterectomy is particularly considered in patients who have recently experienced an ipsilateral TIA or ischemic stroke.

In general:

• Symptomatic 70–99% stenosis: Endarterectomy is strongly recommended in suitable patients.
• Symptomatic 50–69% stenosis: Endarterectomy may be considered based on patient characteristics and procedural risk.
• Stenosis below 50%: Surgery is generally not recommended.

Timing is important after a symptomatic event.

In suitable neurologically stable patients, intervention is often targeted within the first 14 days.

However, large cerebral infarctions, hemorrhage, or other high-risk conditions may require a different approach.

Does Asymptomatic Carotid Stenosis Require Surgery?

Not every severe carotid stenosis requires intervention.

Modern medical therapy has reduced stroke risk in many asymptomatic patients.

Decisions regarding carotid endarterectomy or stenting should consider:

• Degree of stenosis
• Plaque characteristics
• Age
• Life expectancy
• Associated medical conditions
• Procedural complication rates
• Patient preferences

Intervention may be appropriate for selected patients with high-grade asymptomatic stenosis, but it is not routinely recommended for everyone.

How Is Carotid Artery Stenting Performed?

Carotid stenting is an endovascular procedure.

The main steps are:

1. A catheter is advanced to the carotid artery through an appropriate vascular access site.
2. Angiography is used to evaluate the stenosis.
3. An embolic protection system may be used when appropriate.
4. A stent is positioned across the narrowed segment.
5. Balloon dilation may be performed if necessary.
6. Final angiography evaluates vessel patency and cerebral circulation.

Embolic protection devices are designed to reduce the risk of plaque or thrombus fragments reaching the brain during the procedure.

Is Carotid Stenting Better Than Endarterectomy?

There is no single best approach for every patient.

Treatment selection depends on:

• Age
• Lesion anatomy
• Aortic arch and vessel tortuosity
• Plaque calcification
• Surgical risk
• Previous neck surgery or radiotherapy
• Neurological status

Carotid stenting may carry a higher periprocedural stroke risk in older patients and certain anatomical situations.

However, it may be advantageous for selected patients with increased surgical risk or favorable endovascular anatomy.

Treatment should be individualized.

What Are the Risks of Carotid Stenting?

Potential complications include:

• Periprocedural stroke
• Transient ischemic attack
• Vascular access bleeding
• Bradycardia or hypotension
• Arterial injury
• In-stent restenosis
• Rarely, cerebral hyperperfusion syndrome

These risks should be discussed before treatment.

Can a Completely Occluded Carotid Artery Be Stented?

Routine carotid endarterectomy or stenting is generally not recommended for chronic complete internal carotid artery occlusion.

Management depends on vascular anatomy and neurological status.

Acute large-vessel occlusion during ischemic stroke is a different clinical situation and may require emergency endovascular treatment in selected patients.

Are Medications Required After Carotid Stenting?

Yes.

Dual antiplatelet therapy is commonly prescribed for a period after carotid stenting.

Treatment may later be changed to single antiplatelet therapy according to clinical circumstances.

Lipid-lowering therapy and cardiovascular risk factor management should continue.

Medications should not be discontinued without medical advice.

How Is Carotid Artery Disease Monitored?

Follow-up depends on:

• Degree of stenosis
• Presence of symptoms
• Plaque characteristics
• Previous stenting or surgery
• Disease progression

Carotid Doppler ultrasound is commonly used for surveillance.

Who Should Undergo Carotid Ultrasound Screening?

Routine carotid ultrasound screening is not recommended for every asymptomatic adult.

It may be appropriate in:

• Patients with neurological symptoms suggesting stroke or TIA
• Follow-up of known carotid disease
• Surveillance after carotid stenting or endarterectomy
• Selected high-risk patients when results are expected to influence management

Age or elevated cholesterol alone does not automatically justify carotid ultrasound screening in every patient.

Does Carotid Plaque Mean a Stroke Is Inevitable?

No.

The presence of carotid plaque does not mean that a patient will inevitably experience a stroke.

However, it indicates atherosclerotic vascular disease.

Appropriate risk factor management, medical therapy when indicated, and surveillance can reduce the risk of disease progression and complications.

What Are the Warning Signs of Stroke?

Sudden onset of any of the following symptoms may indicate stroke:

• Facial drooping
• Arm or leg weakness
• Speech disturbance
• Sudden vision loss
• Sudden loss of balance or coordination

Emergency medical services should be contacted immediately, even if symptoms resolve.

Time is critical in stroke treatment.

Assoc. Prof. Sezen Bağlan Uzunget, MD
Cardiologist

This content is provided for general educational purposes. Medical treatment, carotid endarterectomy, and carotid stenting decisions should be individualized according to neurological status, stenosis severity, vascular anatomy, and patient-specific risks.