How Does Carotid Artery Disease Affect Your Daily Life?

There are two common carotid arteries, located on each side of the neck.

What is the carotid artery?

The carotid artery is a major blood vessel that supplies blood to the brain, face, and neck. It is present in pairs, with one on each side of the neck, and is distinguished as the left common carotid artery and the right common carotid artery. The common carotid arteries, which arise from the upper chest and travel toward the skull, split into two branches called the internal and external carotid arteries. These two branches then divide into several small artery branches that provide blood supply and nourishment to various organs and tissues in the head and neck region.

The carotid arteries provide blood supply to the head. The external carotid artery provides blood supply to the scalp, face, and neck, while the internal carotid artery supplies blood to the brain.

What is carotid artery disease?

Narrowing the internal carotid artery may decrease the blood supply to half of the brain that it supplies. This narrowing called atherosclerosis (atheroma = lump of plaque + sclerosis = hardening) occurs because of accumulation of plaque on the inside of the artery wall. Plaque begins as a soft, waxy collection of cholesterol and triglycerides but over time begins to harden and calcify. Often it occurs where increased blood pressure and blood turbulence irritate the inner lining of the artery, and this often occurs where the internal and external carotid arteries split (bifurcation).

As the carotid artery begins to further narrow, the pressure within the artery continues to increase. This may cause the plaque to rupture, causing blood clots to form. A large clot may completely block (occlude) the artery or smaller clots and bits of plaque may travel into smaller arteries within the brain and cause disruption of blood supply to parts of brain tissue.

It is only when a stroke or transient ischemic attack (TIA, often referred to as a “mini stroke”) occurs, or a bruit (blowing or whistling sound) is found on physical examination by your doctor, that the diagnosis of carotid artery disease is usually made. Otherwise, the narrowing carotid artery does not cause symptoms.

Carotid artery disease occurs because of damage to the inner lining of the artery. This is a gradual process associated with smoking, high blood pressure, high cholesterol levels, and poorly controlled diabetes. These all may cause minor damage to the inner walls of an artery, and during the healing process, inflammation may occur and plaque may begin to form.

Over time, the area of plaque may grow and narrow the lumen of the artery, the channel where blood flows. It becomes a vicious circle as the narrower lumen increases pressure within the artery and blood turbulence, which leads to more arterial wall damage and more plaque formation. Carotid artery blockage can make it hard for oxygen and nutrients to reach the brain, resulting in stroke and related complications, eventually leading to death.

The risk of narrowing carotid arteries is the same as the risk for those diseases associated with the narrowing of arteries anywhere else in the body, including heart attack, stroke, and peripheral artery disease (PAD).

Those at risk for carotid artery disease include individuals who smoke and those with high blood pressure (hypertension), high cholesterol, poorly controlled diabetes, a family history of atherosclerosis, and advanced age.

Metabolic syndrome also increases the risk of carotid artery disease. It is a grouping of many of the above-listed diseases and to make the diagnosis, three of five of the following need to be present:

• High blood pressure
• High blood sugar
• High triglycerides (one of the types of fat in the blood)
• Low HDL levels (another type of fat)
• Large waistline, a sign of abdominal obesity

Carotid artery disease in itself has no symptoms. It is only when blood flow to parts of the brain is decreased that the diagnosis is made. Decreased blood supply to the brain may result in either a TIA (transient ischemic attack) or stroke (CVA, or cerebrovascular accident).

A transient ischemic attack is a stroke-like group of symptoms that resolves on its own and should be considered a warning sign a stroke is imminent.

Symptoms of a TIA may include:

• Weakness and/or numbness on one side of the body
• Weakness of the face on one side
• Difficulty with speech
• Loss of vision
• Loss of balance
• Confusion

While the symptoms of a TIA tend to resolve on their own in a few minutes, they may last up to 24 hours.

Signs and symptoms of a stroke are similar to a TIA but the effects are permanent without successful treatment.

Since there is no way of knowing whether the symptoms will resolve, any of these symptoms should be considered a medical emergency and the patient or family should call 911 to activate the emergency medical services. Individuals having stroke symptoms may be candidates for treatment with clot-busting drugs or thrombolytics, but the treatment must be initiated within 4.5 hours from the first onset of these symptoms.

The early signs of carotid artery blockage are not visible in most individuals. During your health checkup, your physician may notice an atypical sound called a bruit when listening to your pulse. This faint whistling sound is considered an early sign of carotid artery blockage. Carotid artery blockage may have various risk factors, one of them being age. Age is an independent risk factor for carotid artery blockage. As people age, the risk and severity of carotid artery blockage also increases.

When a person has a TIA or stroke, a doctor may take a history to evaluate the source of the bleeding. The carotid arteries may be evaluated as a potential cause of the TIA or stroke. This is an important part of the diagnosis and treatment of a transient ischemic attack since a TIA is a warning sign a stroke may be imminent. Finding a treatable cause and minimizing the risk of a future stroke is an important component of patient treatment.

Ultrasound is the most common screening test used to determine whether carotid artery stenosis (narrowing) is present. Sound waves are used to understand the anatomy of the artery to see whether narrowing is present. Adding Doppler technology, the amount of blood flow and its velocity can be measured.

Should ultrasound detect carotid artery disease, the next step is to better show the anatomy of the arteries that supply the brain. Angiography is a procedure used to identify any structural abnormalities within the large and small arteries that supply blood to the brain. Historically, angiography was performed with a catheter threaded into the artery and dye injected to outline the blood vessels. In some patients, the artery anatomy can be seen using CT (computerized tomography) or MR (magnetic resonance) angiograms. In both CT and MR angiographies, dye is injected into an arm vein, instead of an artery.

The treatment for carotid artery disease is individualized for each patient and situation. Discuss options with your doctor.

If the carotid artery is less than 50% narrowed, medical treatment is recommended. This includes stepwise antiplatelet therapy. Platelets are blood cells that help clot blood, and in patients who have had symptomatic carotid artery disease, meaning that they have experienced a TIA, decreasing platelet stickiness may help minimize future stroke events.

The first line of medication to treat the disease is aspirin. If the patient was already taking aspirin and still experienced a TIA, the next line medication may be a dipyridamole/aspirin combination (Aggrenox) or clopidogrel (Plavix).

Surgery is a potential option for patients with more significant carotid artery disease.

Two options exist, 1) carotid endarterectomy, and 2) carotid angioplasty with stenting.

1. In an endarterectomy, the surgeon cuts into the artery, removes the plaque buildup, and repairs the artery incision.
2. In angioplasty and stenting, a vascular surgeon or interventional radiologist inserts a catheter into the artery and inflates a balloon squashing the plaque into the artery wall. A stent or cage is then placed at the site to keep the artery open and prevent re-narrowing.

Carotid artery surgery is recommended for symptomatic patients who have carotid artery narrowing greater than 70%. Surgery may or may not be of benefit for symptomatic patients whose narrowing is between 50% and 69%.

Some patients decide to be screened by ultrasound for carotid artery disease even though they have no symptoms. Surgery is a controversial treatment option for asymptomatic patients who have narrowing greater than 60%.

Surgery is not recommended for patients:

• Who have completely blocked arteries because the body may have developed collateral circulation that bypasses the blockage
• Who have already suffered an irreversible stroke because there is no benefit to restoring blood supply to an area of the brain that has already died

Many individuals have some narrowing of their carotid arteries and have no symptoms.

There are benefits and risks for both medical and surgical management of carotid artery disease. The decision as to which treatment is offered depends upon the age of the patient, their neurologic status, their other underlying medical conditions, and the degree of carotid artery narrowing.

The purpose of treatment is to reduce the risk of stroke. In patients whose treatment recommendation includes antiplatelet medications associated with blood pressure, cholesterol, and diabetes control, the risk of stroke after 2 years may be as low as 11%. For patients who qualify for surgery, their risk can fall to 2%-5%, but there are associated surgery risks including stroke, cranial nerve paralysis with hoarseness and difficulty swallowing, and restenosis or re-narrowing of the artery.

The doctor needs to discuss the benefits and risks of treatment to tailor the recommendations to the individual patient's needs.

The life expectancy of a person with a blocked carotid artery depends on various factors including the severity of blockage and other risk factors. The average age of patients with blocked carotid arteries is 70 years. On average, life expectancy is an additional 14 years for men and 16 years for women, provided the condition is well-managed with appropriate medical care.

Brain cells cannot be replaced and do not regenerate. Loss of blood supply to the brain will quickly cause brain cells to die. The eventual result of carotid artery disease is transient ischemic attack and stroke. The narrower the artery, the more likely a stroke will occur. However, it is impossible to say with certainty which individual will or will not develop stroke symptoms.

Prevention is the cornerstone for treating carotid artery disease. Like any other blood vessel in the body, carotid arteries are at risk of narrowing in individuals who smoke, have high blood pressure, high cholesterol, have diabetes, or have a history of heart attack or stroke.

• Living a healthy lifestyle includes eating a well-balanced diet, maintaining an appropriate weight for your height, and exercising routinely.
• Smoking increases the risk of carotid artery disease and stopping smoking is beneficial, even at an older age.
• Lifelong control of high blood pressure, cholesterol, and blood sugars will decrease the risk of developing carotid artery disease.

• What foods should I avoid with a blocked carotid artery? If you have a blocked carotid artery, it's important to avoid foods high in unhealthy fats, sodium, and additives. This includes processed and fried foods, red meat, margarine, sweetened beverages, and foods low in fiber. 
• How can I check my carotid artery for blockage at home? You cannot check carotid artery blockage at home, but you can check for carotid pulse. To do this, place your index and middle fingers gently on the side of your neck, just beside the windpipe. Once you locate the pulse, count the number of beats for 15 seconds, then multiply that number by four to calculate your heart rate per minute. While this can give you an idea of your heart rate, it does not assess for blockages. If you suspect a blocked carotid artery, it’s important to see a health care provider.
• What percentage of carotid artery blockage requires surgery? In symptomatic carotid artery blockage, surgery may be recommended if the narrowing is greater than 70%, whereas in asymptomatic carotid artery blockage, surgery may or may not be recommended if the narrowing is greater than 60%.
• How fast does carotid artery disease progress? The progression of carotid artery disease is typically slow as shown in most studies. The average time for progression is 8-10 years in asymptomatic people. However, for those with other comorbidities, the rate of progression is comparatively faster.