How Does Plaque Cause A Stroke?

Plaque buildup in arteries is a serious health concern. It can lead to heart and brain problems and complications like stroke and heart attack.

J. Michael Tuchek, DO, FACS, a cardiothoracic and vascular surgeon at Franciscan Health, discusses the causes of plaque buildup, its risk factors for stroke and explores effective preventive measures and treatments to protect you.

What Is Plaque?

Unlike dental plaque caused by food buildup in your mouth, plaque is the buildup of cholesterol, calcium and other fatty substances lining your arteries. Even good cholesterol sometimes can cause plaque buildup. Plaque can affect every artery in your body but is especially dangerous in the pathways leading to your heart and brain.

Two main conditions contribute to plaque buildup: atherosclerosis and arteriosclerosis.

Atherosclerosis occurs when fats and cholesterol build up in the arteries. Arteriosclerosis occurs when calcium-filled plaque hardens the arteries and restricts blood flow. Most people have both types, Dr. Tuchek said.

“Some buildup is more dangerous than others, depending on their location,” said Dr. Tuchek, an independent physician who chooses to practice at Franciscan Health Crown Point. “If they’re in your carotid artery (the major artery supplying blood to the brain), they cause a stroke. If they’re in your coronary artery, your heart arteries, it causes a heart attack. If it’s in your leg, you can get leg pains when you walk. So there’s a host of risk factors for excessive plaque buildup.”

What Is A Stroke?

A stroke occurs when the blood supply to the brain is blocked or there is bleeding in the brain. The two types of strokes include an ischemic stroke, when plaque or a clot cuts off the blood supply, and a hemorrhagic stroke, caused by sudden bleeding in the brain. A transient ischemic attack (TIA) is a mini-stroke temporarily blocking the blood supply to the brain.

How Does Plaque Cause A Stroke?

Just as plaque buildup can cause blockages in the arteries leading to the heart, plaque can form in the carotid artery which carries blood to the brain. When this artery is blocked, a stroke can occur. In fact, carotid artery disease is one of two main causes of stroke.

Sometimes, but not always, people at risk of stroke will experience a trans-ischemic attack (TIA), or mini-stroke and will experience trouble speaking, numbness on one side of the body or vision changes that last a short period of time or longer.  

What Are Risk Factors for Plaque Buildup In The Arteries?

Several risk factors contribute to the formation of excessive plaque, said Dr. Tuchek.

“Some risk factors are unavoidable, including age and family history. Even genetic predisposition can result in plaque formation from good cholesterol,” said Dr. Tuchek. “But other risk factors result from lifestyle choices, so modifications and preventive measures can reduce the risk of plaque development.”

Common risk factors for plaque buildup in the arteries include:

• Age
• Family history
• Diabetes
• High cholesterol
• Hypertension (high blood pressure)
• Obesity
• Sedentary lifestyle
• Smoking

How Do Doctors Detect Plaque Buildup In Arteries?

Your physician can detect plaque buildup by performing non-invasive tests like carotid Doppler ultrasounds, echocardiograms or CT angiogram scans.

“These easy tests are painless, and they can detect sources of a potential stroke from the heart, from the carotid arteries, and in the brain itself,” said Dr. Tuchek. “Then we can target those areas with stents or minimally invasive surgery to clean out the plaque that causes strokes. You can cure them before they do harm.”

“A non-invasive carotid Doppler ultrasound provides valuable insights into the health of your carotid arteries. It can tell us the speed of blood flow, any changes and if the arteries are narrowing,” said Dr. Tuchek. “When a blockage reaches 60 to 70 percent, further tests like CT scans can help us understand plaque characteristics, which guide appropriate treatments to prevent a stroke.”

Doctors use other tests, such as an echocardiogram (a non-invasive ultrasound procedure), to detect potential heart abnormalities like clots that may increase the risk of stroke.

Still other tests, like a CT angiogram, uses both a scan and an injected contrast material to examine the blood vessels in your body.

“The contrast material helps us identify any abnormalities in the blood vessels in the brain, heart or lungs,” Dr. Tuchek said. “We can use it to find clogged blood vessels that have formed inside the brain.”

How is Plaque Buildup Treated to Prevent Stroke?

Because a stroke can be a devastating condition resulting in long-term disabilities and care, the best treatment is prevention.

“If the plaque is there, and we think it’s significant based on our tests, we can address it directly to prevent a stroke from ever happening,” Dr. Tuchek said.

Vascular specialists have a vast range of options for patients, including:

• Medications to lower cholesterol and blood pressure
• Smoking cessation
• Controlling blood glucose levels

In more advanced cases, vascular surgeons have surgical and minimally invasive ways to remove plaque from arteries, which often require only an overnight hospital stay.Treatment to help prevent stroke include stents (a tiny tube inserted to open a blood vessel) or carotid endarterectomy (surgery to remove plaque and widen the artery).

Dr. Tuchek explained that stents are the simplest way to treat a blockage.

“These tubes are less invasive and can push plaque aside,” he said. “Stents do great work short-term, but the artery is still smaller than when you were born. So the recurrence rate is a little bit higher.”

Carotid endarterectomy, the gold standard surgical procedure, removes plaque and enlarges the artery, which reduces the chances of a future blockage significantly.

“This procedure uses small, two- or three-inch incisions to open the artery and remove the plaque buildup,” Dr. Tuchek. “Then we patch the artery to make it bigger than the artery you were born with.”

Carotid endarterectomy makes it much harder for the plaque to build up and narrow the artery in the future.

What Diagnostic Tests Can Detect Plaque Buildup?

Doctors use several non-invasive tests to determine if you’re at risk for a stroke.

“One simple test involves a doctor listening to your carotid artery with a stethoscope to detect a bruit, which is a turbulent rush of blood, like a murmur, caused by narrowing and plaque buildup,” said Dr. Tuchek. “Carotid doppler ultrasound tests also offer valuable information about how quickly your blood flows and the extent, if any, of the narrowing in the arteries.”

For more detailed imaging, doctors recommend a CT scan. This high-definition imaging allows them to see the details of the plaque buildup, such as whether it creates a risk of causing a stroke or TIA.