WHAT IS PERIPHERAL ARTERIAL DISEASE (PAD)?
The information on this page is intended to benefit and inform patients who may have been diagnosed with PAD
Peripheral arterial disease (PAD) is a narrowing of the arteries that supplies blood to your legs. The narrowed arteries cannot carry enough blood, which may cause you to experience pain in your legs when walking or doing daily activities. Most people however, may never have any symptoms and do not realise they have PAD until it leads to a heart attack or a stroke.
WHAT CAUSES PAD?
PAD is caused by the same thing that can cause a heart attack or stroke, blocked arteries.
A blocked artery is caused by a blood clot. Blood clots occur in the arteries because fatty material (called plaque) that is deposited in the arterial wall ruptures. The plaque builds up (a process called atherosclerosis) and narrows the artery; when this plaque ruptures, the blood clot forms over the rupture and can block the artery. The process of a blood clot forming over the plaque rupture is called atherothrombosis.
Atherosclerosis causes progressive narrowing of the arteries where plaque is deposited in the arterial wall. Atherothrombosis is when plaque ruptures and blood clots are formed that cause the blockage of an artery.
There are four common stages in the development of PAD:
Stage 1: Artery narrowing
The arteries begin getting more narrow but with no other symptoms. PAD develops gradually and can remain unnoticed for long periods. In many cases, it only causes symptoms in the elderly. However, the rate at which the disease develops can vary significantly depending on the individual.
Stage 2: Claudication
Most people with PAD will not experience any symptoms but for those who do, this is normally the first. Also called “intermittent claudication”, it is fatigue, discomfort or pain in the muscles of the legs.
It will normally occur when walking. Specifically, the pain often occurs in the calves, upper legs, buttocks or feet. The pain is a signal that the muscles are suffering from lack of oxygen. Walking puts them under increased strain, so that more oxygen and more efficient blood circulation is required. However, this is not possible due to reduced blood flow in the narrowed arteries.
Stage 3: Advanced PAD: Pain at rest
Failure to stop the progression of PAD leads to the increasing deterioration of the blood circulation. In addition to pain when walking, you may experience pain even at rest, particularly at night if your legs are raised.
Stage 4: Tissue damage
Without proper blood flow, wounds cannot heal. Even a small cut will have difficulty healing. This could lead to infections and permanent tissue damage. In the worst cases, amputation may even be necessary if adequate blood flow cannot be restored. Please note however that amputation occurs in only a very small minority of patients.
RISK OF HEART ATTACK OR STROKE?
If you have PAD then you are at even greater risk of a heart attack or stroke. You face the same risk of heart attack or stroke as a patient who has already had one. Reducing the overall risk factors will also reduce the risk of having a heart attack or stroke.
WHAT ARE THE RISK FACTORS?
The risk factors for PAD are the same as for a heart attack or stroke. Each individual risk factor increases with risk of PAD. The combination of several risk factors makes it particularly dangerous and greatly increases the risk of PAD.
There are certain factors which cannot be influenced, such as age, gender, and predisposition. However, some risk factors are reversible.
The following are a list of the main risk factors for PAD, most of which you can reduce based on your lifestyle choices:
- Diabetes – Diabetes greatly increases the risk of PAD as well as heart attack or stroke. If you have diabetes, you need to take extra precaution and discuss this with your doctor
- High blood pressure
- High cholesterol
- Unhealthy diet
- Lack of exercise
- Excessive alcohol consumption
- Being overweight
HOW TO REDUCE YOUR PAD RISK?
The best way is prevention. You should be aware of the risk factors and make sure you keep them under control. Also, your doctor may prescribe drugs and procedures, which may be used to help prevent or treat PAD.
There are several ways you can reduce your PAD risk, which includes the following:
- Do not smoke
- Eat a healthy diet
- Exercise regularly
- Maintain a healthy weight
- Avoid stress
- Keep your cholesterol low
- Keep your blood pressure low
- Avoid excessive alcohol consumption
In the early stages of PAD, walking exercises are used for treatment. The goal is to reduce symptoms and increase walking distance. Regular exercise has also been shown to be highly effective treatment which can improve the blood flow. Your doctor will be happy to discuss a suitable fitness program with you.
In addition to reducing risk factors, drugs are also used to help prevent and/or treat PAD.
Anti-platelet drugs interact with the blood platelets. The drug prevents the platelets from clumping together and forming clots over the plaque ruptures caused by atherothrombosis. The commonest of these drugs is aspirin.
Fat lowering drugs lower cholesterol. The commonest of these are called statins.
Blood pressure lowering drugs. If your own doctor has found you to have high blood pressure there are a number of very effective ‘anti-hypertensive’ mediations. Many patients need more than one to control their blood pressure.
Your own doctor may also prescribe drugs to strengthen the heart pumping ability such as ACE inhibitors and angiotensin 2 blockers.
There are a few medications which increase walking distance by some meters, however the most important treatments for PAD are stop smoking, keep walking and take an antiplatelet drug, a lipid lowering drug, and an antihypertensive if required.
SURGICAL OR ‘ENDOVASCULAR’ OPTIONS
Surgical procedures are generally only considered in significant cases of PAD. The type of procedure used depends on many factors, including the extent of the disease and the location of the arterial narrowing.
Angioplasty is a process where a narrowed artery is re-opened by threading a wire (catheter) through the artery until it reaches the narrowing. A balloon that is on the tip of the catheter is then inflated which pushes back the plaque or blood clot that caused the narrowing. The artery is re-opened and the blood can flow normally again. In many cases, a small piece of metal called a stent is used to ensure that the artery remains open. The stent is placed around the balloon so when the balloon is inflated, it expands the stent. The catheter is removed but the stent stays in place.
In some cases a bypass operation may be more advantageous. This process involves taking a vein from somewhere else in your body and creating a new path for the blood to flow. It is similar to a bypass for the heart.
The long-term success of angioplasty or bypass operation depends on how consistently you control your risk factors.
Having PAD is not pleasant, but there are simple and effective ways to reduce your PAD risk. By following the advice of your doctor and reducing your PAD risk, it is possible to live a healthy lifestyle.
Author: Professor Jill Belch