Atherosclerosis

Overview

Atherosclerosis is a medical term to describe a condition when fatty deposits build up inside the arteries. Arteries are vessels that carry blood enriched with oxygen and nutrients away from the heart to all tissues of our body. Fats, cholesterol, calcium, and other substances stick with each other, forming atheroma, or plaque, on and in the walls of arteries. At early stages, this leads to the hardening and thickening of arterial walls. But the process could evolve; plaques could rupture and inflame, which leads to the clot formation on them. These processes lead to the narrowing of the arterial lumen and reduction of blood flow. 

Atherosclerosis is the most common vascular disease worldwide. Although mortality rates from ischemic heart disease and ischemic stroke have dramatically declined in most high-income countries, about half of the people aged 45-84 have atherosclerosis.

Pathogenesis and risk factors

The pathogenesis of atherosclerosis is multifactorial and complex. The major risk factors are

• Dyslipidemia (high cholesterol or high triglycerides)
• Hypertension (high blood pressure)
• Diabetes mellitus type 2
• Metabolic syndrome
• Smoking
• Unhealthy diet (eating food high in saturated fat, trans fat, sodium, and sugar)
• Overweight and obesity
• Lack of physical activity
• First-degree relative diagnosed with atherosclerosis before age 50
• Family history of premature cardiovascular disease
• Age older than 45 for males
• Age older than 55 for women

Signs and symptoms

At early stages, atherosclerosis progresses silently, i.e., without symptoms. Only when plaques obstruct 70-80% of the arterial lumen do symptoms develop. Atherosclerosis can affect every artery of our body. Symptoms are diverse, depending on which vessels are affected.

When carotid arteries that supply our brain are narrowed by atherosclerotic plaques, it’s called carotid artery disease. This condition may lead to a transitory ischemic attack (TIA) or ischemic stroke.

Coronary artery disease, or coronary heart disease, is another form of atherosclerosis. Arteries that supply our heart muscle with blood are called coronary arteries. The reduction of blood flow in these vessels leads to heart muscle damage and death. Symptoms of coronary artery disease (ischemic heart disease) are: 

• chest pain (angina)
• back, shoulders, neck, jaw
• dizziness and lightheadedness
• palpitations
• fatigue
• nausea and vomiting

Atherosclerosis also affects renal arteries (renal artery stenosis). The symptoms are:

• high blood pressure
• changes in amount of pee
• swelling (edema)
• fatigue
• itchy and dry skin
• headache
• unexplained weight loss
• nausea, vomiting, lack of appetite

Reduction of blood flow in arteries that supply intestines, called mesenteric ischemia. Symptoms are:

• abdominal pain
• bloating, nausea, and vomiting
• diarrhea
• lack of appetite due to food fear

Peripheral artery disease (PAD) affects arteries that supply arms and legs. The symptoms of the above-mentioned disease are

• muscle pain during walking (intermittent claudication)
• burning or aching pain during rest
• numbness and tingling sensations of extremities
• skin color changes
• frequent skin infections on extremities
• long-term non-healing of wounds or sores on feet

Progression of atherosclerosis may occur gradually (chronic) or acutely. Acute blockage of coronary arteries leads to heart attack. In the case of brain arteries, acute blockage leads to stroke.

Diagnosis

Your healthcare provider will perform a thorough physical exam, ask about your medical and family history, your dietary habits, tobacco consumption, and physical activities, and order blood tests. The latter reveals high blood sugar or high blood cholesterol, which indicates a high risk of atherosclerosis.

Also, your healthcare professional may need some tests to reveal coronary heart disease, carotid artery disease, or other types of atherosclerosis (electrocardiogram, echocardiogram, exercise stress test, angiography, ankle-brachial index, CT scan, Doppler ultrasound, MRI, etc.). 

Depending on the location of affected vessels, you may see a cardiologist (heart), neurologist (brain and spine), nephrologist (kidney), or vascular surgeon (veins and arteries) . 

Treatment

Treatment goals of atherosclerosis include:

• lowering the risk of blood clots
• slowing disease progression
• preventing complications (heart attack, heart failure, stroke, aneurysms, etc.)
• relief of symptoms 
• restore blood flow in narrowed arteries.

These goals are achieved with lifestyle changes, medications, and surgeries.

Lifestyle changes include:

• avoiding tobacco products
• eating a heart-healthy diet (like the Mediterranean diet)
• increase physical activity.

Medications prescribed for:

• blood pressure control
• lowering blood cholesterol
• lowering blood sugar
• preventing clot formation

Common surgeries for treating narrowed vessels include angioplasty, atherectomy, coronary artery bypass grafting, stent placement, etc.

Prevention

Some risk factors of atherosclerosis are modifiable, and some are not. To prevent atherosclerosis, you should:

• Eat a healthy diet.
• Get regular physical activity.
• Keep a healthy weight.
• Avoid tobacco products.
• Treat health issues (diabetes, hypertension, etc.).

Sources:
UpToDate
Mayo Clinic
Clevland clinic
Amrican Heart Association