Contents
What is atherosclerosis?
Atherosclerosis is characterized by the formation of fatty plaques and fibrous tissue on the internal walls of the arteries , causing obstructions that impede blood flow. It is the main cause of heart attacks, strokes and peripheral arterial disease.
Able to affect any artery in the body, the condition starts during childhood / youth and worsens over time. It is asymptomatic during most of its development and is often only discovered after the appearance of some complication. In addition, men are at a greater risk of suffering from the problem than women. However, after menopause , the risk for women is equal to that for men.
Also known as “hardening of the arteries”, the disease brings serious complications since the content of the plaques can loosen and form a thrombus (clot) in the bloodstream, which can obstruct the passage of blood in smaller caliber arteries. As a result, organs and tissues stop receiving oxygen and can die (necrosis).
In the 9th edition of the International Disease Code (ICD-9), atherosclerosis is found by codes 440 and 414.0.
Difference between arteriosclerosis and atherosclerosis
Atherosclerosis is actually a subtype of arteriosclerosis, a condition in which vessel walls thicken and harden, losing elasticity and impairing blood flow.
It is a very common condition in old age due to natural physiological processes, however the main characteristic of arteriosclerosis is that it occurs even without the deposit of fatty plaques on the arterial walls.
How atherosclerosis develops
The internal walls of the arteries are formed by several layers, and the innermost layer, in which the blood has contact, is smooth, regular and uninterrupted. This layer is called the endothelium.
When an injury or illness occurs in the endothelium, blood-protecting cells called monocytes and T-cells come into play to repair it. They penetrate this wall and become foamy cells (called macrophages) that absorb lipids from the bloodstream, especially low-density cholesterol (LDL).
In this process, there is an inflammation in the blood vessel wall, which causes smooth muscle cells to enter this intermediate layer, in an attempt to create a protective coating. There, the cells multiply, at the same time that fats accumulate in that region. In addition, other substances start to accumulate inside: cholesterol crystals, cell debris and calcium, generating a fibrous plaque.
This accumulation of substances is called atheroma or atherosclerotic plaque . When these plaques become very large, they expand the internal walls of the artery, reducing the space for blood to flow. These walls also lose their elasticity and become more hardened.
Atheromas can be classified as follows:
- Stable: they are plaques that regress, remain static or increase very slowly, being dangerous only when they grow large enough to cause an obstruction of the artery;
- Unstable: these are more vulnerable plaques, which are easily broken and come loose into the bloodstream, causing the blood to form a clot (thrombus), which can obstruct the flow anywhere in the circulatory system.
It is worth mentioning that atheromas can form in any medium or large caliber artery and are irregularly distributed, that is, they do not form in just one place. However, there is a greater incidence in the branches of the arteries, probably due to the greater probability of lesions in these areas, as well as a certain endothelial dysfunction that impairs the anti-inflammatory process, responsible for preventing major problems within the blood vessel.
Atherosclerosis causes and risk factors
The damage to the vessel walls is believed to be caused by factors such as high cholesterol and hypertension, especially where there are bifurcations and the blood swirls during passage. Even so, there is no clear reason for the formation of atheromas.
There are, however, some risk factors that increase the chances of plaque formation, but many people suffer from the disease without even having any of these factors.
It is seen that many of these risk factors are closely linked and can be prevented. Thus, it is possible to focus on eliminating one of the risk factors and ending up eliminating several. This is important because the best measure against atherosclerosis is prevention.
The main risk factors are:
High cholesterol
Blood cholesterol levels play an important role in atherosclerosis, since atherosclerotic plaques are formed, in part, by cholesterol crystals. It is worth remembering, however, that a certain level of cholesterol is healthy, as it has important functions in the body.
Cholesterol does not dissolve in the blood and, therefore, must be transported by lipoproteins, called LDL, VLDL and HDL. Understand:
- Low density lipoprotein (LDL): takes cholesterol to the tissues, being popularly known as “bad cholesterol”;
- Very low density lipoprotein (VLDL): it takes triglycerides and cholesterol into the tissues, it is also called “bad cholesterol”, although many people are unaware of its existence;
- High density lipoprotein (HDL): known as “good cholesterol”, HDL is the lipoprotein that does the reverse transport, taking excess cholesterol from the tissues and taking it to the liver, preventing the accumulation of bad cholesterol in the organs.
High values of VLDL and LDL are harmful to health because they cause more fat to accumulate in the tissues, including the arteries, increasing the possibilities of atherosclerotic plaque formation. Meanwhile, high HDL values do the opposite: they remove fats from where there is excess, establishing balance.
The type of lipoprotein is determined by the fats it must carry. Saturated and trans fats increase LDL levels, while poly and monounsaturated fats raise HDL.
Age
Age is a major risk factor because it is known that, over time, the level of cholesterol in the blood tends to increase, as well as the arteries undergo physiological processes that lead to the hardening of their walls (arteriosclerosis), creating a favorable scenario for the formation of atheromas.
Hypertension
Blood pressure above 110 / 75mmHg increases the risk of cardiovascular disease. In addition, when you already have atherosclerosis, hypertension increases the chances of complications such as heart attack and stroke.
In people with diabetes or kidney disease, the ideal is that the pressure is below 130 / 80mmHg, in order to avoid the complications of the disease.
Diabetes
It is known that people with diabetes, both type 1 and type 2, tend to develop atherosclerosis in large arteries, in addition to presenting this disease at an earlier age. Another problem is that people with diabetes mellitus (type 1) can develop a disease that affects small arteries, such as those in the eyes, nerves and kidneys, which can lead to problems such as loss of vision, nerve damage and kidney failure.
The risk of developing atherosclerosis in diabetics is 2 to 6 times higher than in healthy people, especially in women, even before menopause.
Obesity
The obesity , especially abdominal increases the chance of developing other risk factors for atherosclerosis, such as hypertension, type 2 diabetes and high cholesterol. Therefore, it also becomes a risk factor for the disease.
Smoking
Tobacco consumption, whether through tobacco or chewing tobacco, increases the risks of any disease related to the cardiovascular system, especially atherosclerosis. That’s because tobacco decreases the amount of good cholesterol (HDL) and increases bad cholesterol (LDL) in the blood. In addition, smoking increases the levels of carbon monoxide in the blood, which increases the risk of damage to blood vessel walls.
The smoking also brings more problems for the heart and arteries. Smoking causes the arteries to contract, worsening the flow of blood to the tissues, in addition to increasing the tendency of clotting in the blood, which can generate thrombi in the bloodstream.
Alcohol abuse
On the one hand, alcohol increases HDL levels in the bloodstream and decreases the chances of clots (thrombi) forming. Therefore, its consumption may seem a good alternative for prevention. However, over-moderate consumption increases the risk of liver disease, which can impair cholesterol levels and increase the chances of developing atherosclerosis.
It is recommended that men do not exceed more than 14 doses per week and, for women, this number drops to 9 doses. People who drink more than that should cut back on consumption, while people who don’t drink should stay that way.
Sedentary lifestyle
Sedentary lifestyle is linked to the development of several cardiovascular diseases, especially atherosclerosis. Even to a moderate degree, regular physical exercise reduces risks, as it helps to lose weight (prevents obesity), reduces blood pressure, cholesterol levels and insulin resistance.
Familial hypercholesterolemia
Familial hypercholesterolemia is a condition in which the individual naturally has high blood cholesterol levels, without this cholesterol having been acquired through food.
Hyperhomocysteinemia
Hyperhomocysteinemia is characterized by high levels of homocysteine (an amino acid) in the blood. This condition is usually caused by an inherited disorder. Excess homocysteine can directly injure the internal walls of the arteries, increasing the chances of atherosclerotic plaque formation. In addition, it also assists in the formation of blood clots, increasing the risk of other related problems.
Symptoms
To some extent, atherosclerosis is asymptomatic and the patient only suspects that there is something wrong when the obstruction in the artery is already large enough that there is difficulty in bringing oxygen to the other organs and cells.
As atheroma can form anywhere in any artery, symptoms depend heavily on the affected areas. The most common is that plaques are formed in the carotid arteries (which carry blood to the brain), coronary arteries (which feed the heart itself), femoral, popliteal and tibial arteries (which carry blood to the legs) and kidneys.
Carotid arteries
They are the arteries responsible for carrying blood to the brain. When there are plaques at any point, there is a very high risk of stroke and the main symptoms to pay attention to are:
- Headache;
- Shortness of breathe;
- Weakness / numbness in the limbs;
- Difficulty speaking;
- Mental confusion;
- Facial paralysis;
- Temporary loss of vision in one eye.
Coronary arteries
When there are obstructions in the arteries that supply the heart itself, the consequences can be severe. You should be aware of the following symptoms:
- Chest pain;
- Feeling faint;
- Cough;
- Craving and vomiting.
Femoral, popliteal and tibial arteries
If the obstruction is in the arteries that irrigate the legs, it is possible that there is intermittent claudication, a type of pain in the lower limbs that is present when walking and during exercises, indicating a lack of oxygen.
Renal arteries
In the renal arteries, the obstruction can cause kidney failure. Thus, symptoms that appear frequently in these cases are:
- Swelling in the extremities;
- Hypertension;
- Difficulty concentrating;
- Loss of appetite.
How is atherosclerosis diagnosed?
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In many cases, the diagnosis is only made when there has already been some complication, such as, for example, after a heart attack . However, the diagnosis can be made long before that, with simple tests like the lipidogram.
The doctor, usually a cardiologist, can order a battery of tests to make sure that there are no other conditions causing the symptoms. The choice of tests will depend on the location of the symptoms, which is the main clue to know where the obstruction is.
Learn more about each exam:
Physical exam
During a physical examination done inside the office, the doctor can look for signs that the arteries are narrow and hardened, such as:
- Weakened pulse;
- Hypotension in the lower limbs;
- Using a stethoscope, look for different sounds in the arteries.
Fasting blood glucose
The fasting blood glucose test consists of taking a blood sample from the patient after 12 hours of fasting, in order to measure the levels of glucose (sugar) in the bloodstream. Too high or too low values can indicate poorly controlled diabetes, which is a risk factor for atherosclerosis.
Lipidogram
The lipidogram is an exam that analyzes the amount of fats in the bloodstream, done with the withdrawal of a blood sample, also on an empty stomach. This test shows the amount of total fats, HDL, LDL and triglycerides.
Ideally, total fat levels should be between 140 and 200mg / dL. When the LDL level is below 130mg / dL and HDL above 40mg / dL, there is a decreased risk of heart attack and diseases related to increased cholesterol in the bloodstream.
High LDL values may indicate atherosclerosis, since it is one of the risk factors for the disease. This result may also point to familial hypercholesterolemia, a condition in which the individual naturally has more low-density cholesterol in the bloodstream.
Ultrasound with Doppler
In Doppler ultrasound, blood pressure is measured at different points in the arteries and veins. Through this exam, the doctor can determine the severity of possible obstructions, as well as check the speed of the blood in the arteries.
Ankle Brachial Index (ITB)
In this exam, the blood pressure of both arms and ankles is measured in order to detect a difference between them. A change in these measurements is a strong indication that there is some obstruction in the path.
Magnetic resonance angiography (MRA)
Through the application of a contrast in the blood circulation, the ARM is able to create clear images of the blood vessels. When analyzing these images, the doctor can detect changes in the thickness of the arteries, as well as see parts where blood flow is less due to obstructions.
Cardiac catheterization
When the obstruction is suspected to be in the heart, a cardiac catheterization helps to find the exact location of the atheroma. In this examination, a catheter is placed in a peripheral blood vessel in the arm, thigh or neck, and is guided to the heart.
This catheter deposits a contrast in the blood vessels so that they are more visible on radiographs. Through this contrast, it is possible to observe whether there are atherosclerotic plaques in the coronary arteries.
Is atherosclerosis curable? What is the treatment?
The best treatment for atherosclerosis is prevention, since there is no cure . When observing the risk factors, the patient should seek to have a lifestyle with healthy habits so that he can avoid the formation of plaque in the vessels.
However, when a diagnosis is already in place, treatment can be done either with medications or with lifestyle changes, in order to prevent plaque growth. The treatment, in these cases, is very focused on the complications of the disease. In the latter case, some types of surgery may be used.
Lifestyle changes
In order to avoid a worsening of the condition, the patient must have healthy habits such as a balanced diet and the practice of frequent physical exercises that, in turn, fight overweight. In addition, it is recommended to get rid of harmful addictions such as smoking and alcohol.
Physical exercises
The World Health Organization (WHO) recommends that people practice between 75 and 150 minutes of physical exercise per week, depending on the intensity. To achieve this goal, one can plan as follows:
- 150 minutes (2h30min) of walking or cycling during the week and strength exercises – such as lifting weights – two or more times, to work the main muscles;
- 75 minutes (1h15min) of running or skipping rope during the week and strength exercises two or more times;
- Mixed moderate and intense activities, such as 60 minutes of running and 30 minutes of walking, for example, in addition to strength exercises two or more times.
Diet
Diet is one of the main factors for preventing fat deposits on arterial walls. A balanced diet is one that guarantees the necessary nutrients without an increase in harmful substances in the body, such as low-density cholesterol.
It is known that saturated and trans fats are responsible for greater production of LDL, which increases the amount of cholesterol in the tissues. Meanwhile, poly and monounsaturated fats help increase HDL. Therefore, people should give preference to foods with more unsaturated fats and less saturated and trans fats.
It is worth remembering that liquid fats (oils and some margarines) have more poly and monounsaturated fats, while solid fats (butter and lard) have more saturated and trans fats. In addition, two very important polyunsaturated fats are omega 3 and 6, found in fish, canola oil and safflower, sunflower and corn.
It is recommended to avoid the following types of foods:
- Fatty and processed meats, such as sausages and sausages;
- Fast food ;
- Butter;
- Cream;
- Cheeses;
- Cookies and cakes;
- Coconut and palm oil.
Foods that should be eaten more often are:
- Fish oil;
- Avocado;
- Seeds, cereals, chestnuts and nuts;
- Sunflower, canola, safflower, rapeseed and olive oil.
Stop smoking and decrease alcohol intake
Quitting smoking is not an easy task, but with the help of a doctor and psychological treatment, this is entirely possible. The risk of developing atherosclerosis halves in ex-smokers, regardless of whether they have stopped smoking months or years ago.
Regarding alcohol intake, the recommendation is to drink a maximum of 1 drink per day, in the case of women, or 2, in the case of men.
Drug treatment
There is no specific drug for atherosclerosis, any more than any drug would be able to reduce already formed atherosclerotic plaques. However, doctors often prescribe drugs that fight the complications of the disease.
The main drugs indicated by doctors are vasodilators, anticoagulants, statins (help to reduce LDL levels) and diuretics.
Surgeries
Ultimately, there are some surgeries that can be done to improve the patient’s quality of life. However, it is worth mentioning that none of them are able to cure atherosclerosis.
Stent angioplasty
In stent angioplasty, a catheter is guided to the location of the atherosclerotic plaque, where it leaves a metal tube in the form of an expandable mesh that pushes the plaque, expanding the caliber of the artery and allowing the passage of blood.
Endarterectomy
Endarterectomy consists of opening the artery in order to remove the atherosclerotic plaque from its internal wall. It is usually done in the carotid artery, in order to avoid strokes, being called carotid endarterectomy.
Fibrinolytic therapy
When thrombi are formed, an alternative is fibrinolytic therapy, which aims to dissolve these clots. Fibrinolytics are substances capable of activating an enzyme that degrades fibrin, responsible for the formation of thrombi. The administration of these drugs is done directly in the bloodstream, in a hospital environment, and has a very high effectiveness in the first 24 hours after the first symptoms.
Some of the substances used for fibrinolytic therapy are streptokinase, urokinase rt-PA, together with anticoagulant drugs such as heparin. The greatest risks of this therapy are anaphylactic shock (mainly with streptokinase) and internal bleeding.
Vascular bypass
Also known as arterial bypass, vascular bypass is a type of surgery in which a new path for blood flow is built. The procedure consists of taking a graft from a vein (usually from the leg, chest or arm) or a synthetic tube and connecting it to the artery where there is the block, bypassing it and generating a deviation to the blood flow. In this way, the blood reaches the tissues without major difficulties.
This surgery can be done in several arteries, but the best known form of the operation is the Saphenous Bridge, in which a part of the saphenous vein (of the leg) is connected to a coronary artery, preventing heart attacks.
Alternative therapy
There are several foods and supplements that can help treat atherosclerosis. However, it should be noted that there is no scientific proof of the effectiveness of these substances, in addition to the possibility of drug / food interaction , which can put the patient’s health at risk.
It is recommended to always talk to the doctor before starting any type of alternative treatment, in addition to making sure not to abandon the clinical treatment, since the two treatment modalities are only complementary, without being able to replace each other.
Some examples of supplements and foods used for atherosclerosis are:
- Alpha-linolenic acid;
- Barley;
- Beta-sitosterol;
- Black tea and green tea;
- Plantago ovata ;
- Calcium;
- Cocoa;
- Cod liver oil;
- Fish oil;
- Ubiquinone (Coenzyme Q10);
- Folic acid;
- Garlic;
- Oat bran;
- Sitostanol;
- Vitamin C.
How to reverse atherosclerosis?
Unfortunately, there is no way to reverse atherosclerosis , only ways to make it less dangerous to the patient’s health. Drug treatment, together with a balanced diet, is able to prevent atherosclerotic plaques from becoming larger, but they are not enough for them to decrease in size or for vessels to regain their elasticity.
Some drugs are able to lower the level of bad cholesterol (LDL) in the blood by blocking the function of the liver in the synthesis of this substance. However, this only prevents greater deposits of cholesterol in the plaques, with no guarantee that other substances will not join the atheroma and make it bigger. That is why it is important, even with drug treatment, to remain physically active and to have a balanced diet.
Complications and consequences of atherosclerosis
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Because it is a vascular disease, atherosclerosis can have very serious consequences and even lead to death. Understand better about each of the consequences of atherosclerosis:
Coronary artery disease
It occurs when atherosclerosis causes the narrowing of the coronary arteries, responsible for the irrigation of the heart itself. This disease itself has several serious complications, such as angina and acute myocardial infarction .
Carotid artery disease
When it affects the carotid arteries, which carry blood to the brain, atherosclerosis can easily cause a transient ischemic attack (Mini-stroke) and even the stroke itself.
Peripheral arterial disease
By affecting the arteries of the upper and / or lower limbs, atherosclerosis causes circulatory problems in the arms and legs. These problems can lead to less sensitivity to heat or cold, which can increase chances of getting burned or frozen ( frostbite ).
In more severe cases, tissue necrosis ( gangrene ) can occur .
Aneurysm
An aneurysm is an abnormal dilation of a blood vessel with weakened walls. It can occur in any part of the body and, in general, does not cause major problems.
However, these vessels can rupture, causing a lot of pain and characterizing a medical emergency, as it results in internal bleeding and ischemia (lack of blood supply to the tissues).
When it is in the brain, the aneurysm can also result in stroke, especially of the hemorrhagic type.
Thrombosis
When the content of an atherosclerotic plaque leaks out of the inner wall, a clot is formed, called a thrombus.
When it is lodged, this thrombus worsens the obstruction, but it can make the situation even worse when it loosens and travels all the way through the blood through the vessels. This is because it can obstruct smaller caliber arteries and veins and, in extreme situations, cause pulmonary embolism .
Chronic renal failure
When the renal arteries are affected, the lack of blood in the kidneys prevents it from being filtered properly. This causes harmful substances to continue circulating in the bloodstream, which in turn increases the chances of cardiovascular problems, bleeding and infections.
Does atherosclerosis kill?
Whether atherosclerosis can kill or not depends a lot on where the atherosclerotic plaque forms. This is because it leads to death through its complications, such as coronary and carotid artery diseases.
In general, atherosclerosis is the leading cause of heart attacks and strokes, conditions that can kill quickly.
Living together: what to expect in the future?
Receiving the diagnosis of atherosclerosis can be quite disconcerting, since the disease is linked to several fatal conditions. However, with treatment and lifestyle changes, it is possible to prevent a worsening of the disease.
It is extremely important that the patient follows the treatment properly and is always in contact with his doctor to avoid possible complications. Another important issue is to keep risk factors in check, as they can help trigger complications.
If necessary, the patient can seek psychiatric / psychological help to treat problems such as depression and anxiety , which can arise after such a complicated diagnosis.
How to prevent atherosclerosis?
The prevention of atherosclerosis is done in the same way as the prevention of any cardiovascular disease : with physical activity and a balanced diet. In addition, some other tips to prevent are:
- Cease smoking and reduce the intake of alcoholic beverages;
- Control risk factors such as obesity, high cholesterol, hypertension and diabetes;
- Monitor cholesterol by doing periodic tests from the age of 40;
- Practice relaxation techniques, such as yoga and meditation, as they help to keep your blood pressure balanced.
As it is one of the main diseases capable of leading to a heart attack or stroke, there is a greater need for preventive measures for atherosclerosis. Share this text with friends and family so that everyone knows the disease and knows how to prevent it.
