Diagnosing atherosclerosis
As atherosclerosis does not cause symptoms until cardiovascular disease occurs, those at risk of developing the condition should be tested.
Screening allows treatment to be given to reduce the risk of cardiovascular disease developing.
Screening is recommended for the following:
- are over 40 years of age
- are overweight or obese
- are a smoker or have a history of heavy smoking
- eat a high-fat diet
- have high blood pressure (hypertension)
- have type 1 or type 2 diabetes
- have a family history of heart disease, high blood pressure or diabetes
There are several tests that assess your level of existing atherosclerosis and your risk of developing cardiovascular disease, including:
- blood tests – to measure the amount of cholesterol in your blood and the amount of glucose, if you are diabetic
- blood pressure tests
- a measurement of your weight and waist size
Ankle-brachial index test will be done to compare the blood pressure in your ankle to the blood pressure in your arm. A difference between the two readings may suggest that atherosclerosis is restricting the blood supply to your legs and that you have peripheral arterial disease.
Further tests
If your risk of developing cardiovascular disease is high or you are experiencing symptoms of cardiovascular disease, further tests may be needed to confirm the level of atherosclerosis and locate any potential blockages in your arteries. These tests are explained below.
Electrocardiogram
An electrocardiogram (ECG) measures the electrical activity of your heart. This test can measure how well your heart is functioning and can often detect the presence of heart disease.
Ultrasound
An ultrasound scanner uses sound waves to build up a picture of the inside of your body. This can be used to measure your blood pressure at different points in your body. Any variation in pressure could point to the site of a blockage in your arteries. Ultrasound tests can also be used to study the larger arteries.
Angiography
During an angiography you are injected with a special dye that can be seen on X-ray. The test is used to see how the blood flows through your body.
Computerised tomography scan
A computerised tomography (CT) scan takes a series of X-ray images and uses a computer to assemble them into a more detailed three-dimensional image. It can often detect narrowing or hardening in the larger arteries.
Ophthalmoscopy
An ophthalmoscopy is a type of eye test where an instrument called an ophthalmoscope is used to examine the blood vessels in the back of your eye. The ophthalmoscope can sometimes detect hardening of the blood vessels in your retina (the retina is the light-sensitive layer at the back of the eye).
Treating atherosclerosis
If you are at risk of developing a cardiovascular disease (CVD) as a result of atherosclerosis, you will be advised to change your lifestyle to reduce this risk.
Lifestyle changes include modifications in the diet and exercise.
Medication
There are several medications available to treat many of the underlying causes of atherosclerosis, such as a high cholesterol level and high blood pressure (hypertension).
Depending on individual circumstances, you may only need to take one medication, or you may need a combination of different medications.
High blood pressure (hypertension)
The most widely used medications for treating high blood pressure are outlined below.
Angiotensin-converting enzyme (ACE) inhibitors
Angiotensin-converting enzyme (ACE) inhibitors work by blocking the actions of some of the hormones that help regulate blood pressure.
ACE inhibitors reduce the amount of water in your blood as well as widening your arteries, both of which will lower your blood pressure.
ACE inhibitors are not suitable for:
- pregnant or breastfeeding women
- people with conditions that affect the blood supply to their kidneys
- those with a history of heart disease
The side effects of ACE inhibitors include dizziness, tiredness and headaches.
If the side effects of ACE inhibitors become troublesome, angiotensin-2 receptor antagonists may be recommended. They work in a similar way to ACE inhibitors.
Calcium channel blockers
Calcium channel blockers work by relaxing the muscles of your artery walls, which causes your arteries to widen and lowers your blood pressure.
Calcium channel blockers are not recommended for people with a history of heart disease, liver disease or circulation problems.
Side effects include a flushed face, headaches, swollen ankles and dizziness.
Drinking grapefruit juice is avoided if you are taking calcium channel blockers because this can cause your blood pressure to fall.
Thiazide diuretics
Thiazide diuretics work by reducing the amount of water in the blood and widening the walls of your arteries.
They are not recommended for pregnant women or people with gout (a type of arthritis where crystals develop inside the joints).
Thiazide diuretics have been known to reduce the level of potassium in your blood, which can interfere with your heart and kidney functions. They can also raise the level of sugar in your blood, which could lead to diabetes.
You will probably be advised to have blood and urine tests every six months so that your potassium and blood sugar levels can be monitored.
A few men reported they could not get or maintain an erection while taking thiazide diuretics, although this side effect resolved once the medication was withdrawn.
High cholesterol levels
Statins
Statins are a type of medication used to lower blood cholesterol levels. Statins block the effects of an enzyme in your liver called HMG-CoA reductase, which is used to make cholesterol.
Statins sometimes have mild side effects, including constipation,diarrhoea and headaches.
Occasionally, statins can also cause muscle pain, weakness and tenderness. You should contact your GP if you experience these symptoms because your dosage may need to be adjusted.
If you have high blood cholesterol, you may need to take statins indefinitely.
Preventing blood clots
As many of the serious complications that arise from atherosclerosis are associated with blood clots, such as heart attack and stroke, you may be given medication to help reduce the risk of a blood clot developing.
Antiplatelets
Medications used to prevent blood clots developing are known as antiplatelets. Platelets are tiny particles in the blood that help it to clot. Antiplatelets work by reducing the “stickiness” of platelets.
A regimen with low-dose aspirin, a nonsteroidal antiinflammatory drug used as an analgesic, has blood-thinning properties.
If tests reveal a greater risk of developing a blood clot than usual, an additional antiplatelet medication called clopidogrel will be given. Clopidogrel can also be used if you are allergic to aspirin.
Surgery
Surgery may be required if certain important blood vessels become narrowed. These are the:
- coronary arteries, which supply blood to your heart (narrowing of your coronary arteries can trigger a heart attack)
- carotid arteries, which supply blood to your brain (narrowing of your carotid arteries can trigger a stroke)
Coronary angioplasty
Coronary angioplasty is a type of surgery used to widen your coronary arteries.
A long, flexible plastic tube called a catheter is inserted into a blood vessel and a balloon attached to the catheter is inflated to widen the artery.
A small metal tube called a stent is often used to help keep the artery open.
Coronary artery bypass graft
A coronary artery bypass graft (CABG) can be used to treat narrowing of the coronary arteries. During a CABG, healthy blood vessel segment (graft) is taken from other parts of the body to bypass the blocked artery.
Segments of vein taken from your legs, arms and chest are used to create a new channel through which blood can be directed around the blocked part of the artery. This enables more blood to get through to the heart muscle.
Carotid arteries
Surgery is usually only recommended to widen the carotid arteries when previous symptoms related to a blocked blood supply has occured, such as a stroke or transient ischaemic attack (TIA).
Unlike the coronary arteries, preventative surgery on the carotid arteries is not usually recommended, except in cases where testing shows high levels of narrowing.
This is because studies have found that the benefits achieved in reducing the risk of a stroke in most people without any symptoms are outweighed by the risks associated with surgery.
Carotid endarterectomy
A carotid endarterectomy is the most commonly used method of widening the carotid artery (the main artery in your neck).
During the procedure, a cut is made into the narrowed part of the artery and the inner lining of the artery is removed, along with any plaque inside it.
Most surgeons sew a patch into the opening to widen this section of the artery. The patch may be taken from a vein in your thigh or it might be synthetic (man-made).
Using a patch can reduce your risk of having a stroke after the operation, as well as reducing the likelihood of restenosis (the artery becoming narrowed again).
Carotid angioplasty
Carotid angioplasty uses a catheter, a thin plastic tube with an inflatable balloon at one end, which is threaded through the femoral artery (main artery in the groin) and up to the carotid artery.
The catheter is guided through fluoroscopy using X-rays to construct an image.
The balloon is then inflated to around 5mm in diameter. This expands the artery, clearing the narrowing so blood is able to flow through it again.
Carotid angioplasty is a less invasive type of surgery than carotid endarterectomy, this will result in less postoperative pain and faster recovery time.
Extracranial to intracranial bypass
A new type of surgery used to treat blockage of the carotid artery is known as an extracranial to intracranial bypass.
A section of blood vessel found outside the skull is diverted and used to bypass the site of the blockage so that the blood supply to the brain can be restored.
Extracranial to intracranial bypass is still an evolving field of treatment and it is unclear how effective or safe it may be in the long term.