Atherosclerotic plaque leads to many diseases of the cardiovascular system. The deposition of atherosclerotic plaque leads, among others, to for atherosclerosis or ischemic heart disease. Atherosclerotic plaque is the accumulation of deposits made of fats in the walls of blood vessels. Check how atherosclerotic plaques are formed, what conditions are conducive to their deposition and what diseases can, as a consequence, cause atherosclerosis.

Atherosclerotic plaquemeans the accumulation of deposits in the walls of blood vessels, consisting of, among others, fats. Factors included in the name of the metabolic syndrome lead to its formation. In short, atherosclerotic plaque build-up is influenced by, among others, diabetes, obesity and abnormal cholesterol.

Atherosclerotic plaque - where is it deposited?

Plaque deposition occurs in all people and begins by the age of 30, involving first the abdominal aorta, and then other arteries: coronary, popliteal, and cervical. As a consequence, the entire arterial system may be involved. Diseases that this process leads to include:

  • ischemic heart disease,
  • lower limb ischemia,
  • carotid atherosclerosis,
  • atherosclerosis of the renal arteries.

Atherosclerosis itself is usually asymptomatic and may develop secretly for many years. Unfortunately, complications are often the first symptom of an advanced disease, which can be very serious. Atherosclerosis is the basis of such conditions as: heart attack, stroke, arterial hypertension, acute limb ischemia, aneurysms or kidney failure.

Atherosclerotic plaque - in whom does it occur?

The speed of the process of atherosclerotic plaque deposition and the growth of the formed plaques depends largely on the lifestyle and the presence of other diseases. The sooner the prevention of atherosclerosis is started, the better, because thanks to this you can slow down the pace of its development as much as possible. It has been proven that the factors contributing to this disease are:

  • hyperlipidemia, or excess cholesterol, especially "bad" - LDL,
  • smoking,
  • diabetes,
  • hypertension,
  • obesity,
  • lack of physical activity and poor diet,

We can all these factorsmodify and significantly reduce the severity of the enlargement of atherosclerotic plaques through a he althy lifestyle. There are also several factors that are beyond our control:

  • age and gender (men and the elderly are more at risk),
  • a family history of heart attacks.

It is generally recognized that the most important factors contributing to the early development of atherosclerosis are included in a unit called the metabolic syndrome, which includes diabetes, obesity, and abnormal cholesterol, among others.

Atherosclerotic plaque and the structure of arteries

In order to understand the process of atherosclerotic plaque formation, it is necessary to understand the basics of the structure of the artery walls. These vessels are not a uniform structure, but contain 3 layers, they are:

  1. The inner membrane, otherwise known as the endothelium. It is made up of only one thin layer of cells. They provide a smooth lining of the vessel, which allows an undisturbed, laminar blood flow.
  2. The medial membrane is the thickest shear layer of the vessel, containing primarily elastic fibers and smooth muscle cells. The role of the medial membrane is to regulate the diameter of the vessel, so they are responsible for adjusting the pressure and intensity of blood flow to ensure that it is delivered to organs as needed.
  3. Additional membrane covering the outside of the vessel and giving it shape.

Atherosclerotic plaque - the mechanism of formation

Atherosclerotic plaque (aka atheroma) is a deposit in the wall of a blood vessel, while atherosclerosis is a systemic process of their deposition. The formation of atherosclerotic plaques is a long and multi-stage process, in short it is as follows:

  1. Correct wall of the artery, under the influence of atherosclerosis risk factors or, for example, the inflammatory process, the tight endothelium is damaged and the inflammatory cells and smooth muscles penetrate the vessel wall. The exact causes and mechanisms of atherosclerosis are not fully understood.
  2. Deposits are deposited between the middle and inner membranes.
  3. The food cells absorb the lipids - mainly LDL cholesterol, which becomes the foam cells.
  4. Deposits undergo changes: proliferation of muscle cells, oxidation of fats, and the deposition of collagen and lipids - both inside and outside the cells.
  5. The formation of atherosclerotic plaque results in a bulging into the vessel lumen and restriction of blood flow.
  6. Cells of the immune system trigger a local inflammatory process that keeps the response runningcholesterol is deposited and plaque growth is intensified. In addition, cell death and calcification occur within the plaque.
  7. A mature atherosclerotic plaque is composed of a superficial layer - a cap and a lipid core.
  8. The calcium content of the plaques increases over time.Until now, the development of atherosclerotic plaques is asymptomatic.
  9. Rupture of atherosclerotic plaque. Years after the beginning of this process, the atherosclerotic plaques may break and its contents may be released into the bloodstream.

The result of rupture is, on the one hand, embolism, if the torn pieces of the plaque continue to flow with the bloodstream and obstruct small vessels, but also thrombosis. The second process is more frequent and equally dangerous because it leads to the complete closure of the vessel in the place of the pre-existing plaque. Why is this happening?

A broken plaque is recognized by platelets as damaged vessel continuity, clotting begins, as in the case of, for example, an injury. However, in this case there is no leakage of blood outside the vessel, and what is more, the ruptured atherosclerotic plaque is constantly releasing its contents, so the clotting process does not stop, and the vessel lumen is closed.

Particularly young atherosclerotic plaques are prone to cracking, as they contain little fibrous tissue, which makes their walls durable. Such plaques, called unstable, are not large and narrow the artery to a small extent, often asymptomatically. As a result, people without symptoms of atherosclerosis experience sudden events, such as the previously mentioned heart attacks or strokes.

Atherosclerotic plaque - structure

The size of an atherosclerotic plaque is usually 0.5 to 1.5 cm, although they may stick together to form large lesions. The atherosclerotic plaque is a locally raised lesion, made of a core and a cap. The core consists of random lipid masses, sometimes called debris, which consists of cholesterol, foam cells, and calcium. These foam cells are large, fat-laden food cells - macrophages.

The cap, in turn, covers the core, separating it from the bloodstream, it is made of collagen, smooth muscle cells, cells of the immune system. Within the atherosclerotic plaque, a process called neovascariation can also occur, which is the formation of new, small vessels within them. Atherosclerotic plaques are not a permanent formation, metabolic processes take place within them, causing their constant transformation, which also contributes to their rupture.

As mentioned before,advanced atherosclerotic lesions can cause various secondary processes:

  • rupture causing clots and blockages,
  • bleeding into the plaque, which may result in rupture,
  • thrombosis on the plaque, causing its enlargement or complete closure of the vessel,
  • pathological dilatation of the artery and aneurysm formation.

Atherosclerotic plaque and symptoms of atherosclerosis

As mentioned earlier, atherosclerosis is in many cases asymptomatic, because small deposits do not restrict blood flow. It is only the lamellae occluding more than 50% of the vessel lumen that causes discomfort, as they reduce the volume of blood flowing, hence there is a deficiency of nutrients and oxygen, which causes concern. Initially, they appear during increased blood demand - in exertion, as plaque builds up - also at rest.

If the coronary arteries are involved, chest pain, shortness of breath and fatigue appear. In the case of the arteries of the lower extremities - pain at first when walking, and then also at rest.

Atherosclerotic plaque and the treatment of atherosclerosis

Treatment of atherosclerosis is not about treating atherosclerotic plaque, but preventing plaque from forming, and stabilizing existing ones to prevent complications. The most important procedure in the case of atherosclerosis - regardless of location, is the reduction of risk factors: quitting smoking, weight loss in overweight people, which can be achieved by increasing physical activity and introducing an appropriate diet.

In addition, attention should be paid to the proper treatment and control of diabetes and high blood pressure. The effect of blood cholesterol is also significant, so in addition to an appropriate diet, sometimes drugs that reduce cholesterol - the so-called statins - are introduced.

If pharmacological treatment is ineffective and atherosclerosis causes symptoms, endovascular surgery or classic surgery may be necessary. Endovascular procedures involve the expansion of atherosclerotic lesions with a balloon and then the implantation of stents. The "classic" surgeries involve the removal of an atherosclerotic plaque or the sewing of bridges bypassing the stenosis.

Atherosclerosis is most often associated with heart disease, but it may affect all arteries of the body and develop in a similar way. It is a chronic inflammatory disease of the arteries, the starting point is damage to the endothelium, i.e. the inner, delicate layer of the artery. It occurs as a result of blood flow disorders or an ongoing inflammatory reaction.

As a result, deposits composed of many substances and cells, including fat, are deposited in the vessel wall - these are plaques. Under favorable conditions, they enlarge over time, it also happens that they break, which leads to the detachment of their fragments and the formation of blood clots.

The development of atherosclerosis leads to a narrowing of the vessel lumen, which in turn limits blood flow and hypoxia - initially only during its increased demand, and then, along with the increase in plaque size, also at rest. It is obvious that atherosclerosis can occur simultaneously in different arteries in the same person, therefore the diagnosis of e.g. ischemic heart disease significantly increases the probability of occurrence of e.g. peripheral artery disease.

The final stage of the disease is the complete closure of the vessel, which may result from such a large development of atherosclerotic plaque or its damage. The second mechanism is represented by the so-called unstable plaques, which break easily, while platelets recognize a shear vessel as a rupture and begin to attach at this point. At some point, the process gets out of control, the artery is closed and ischemia occurs.

About the authorBow. Maciej GrymuzaA graduate of the Faculty of Medicine at the Medical University of K. Marcinkowski in Poznań. He graduated from university with an over good result. Currently, he is a doctor in the field of cardiology and a doctoral student. He is particularly interested in invasive cardiology and implantable devices (stimulators).

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Cardiology