These changes are regional and form recognisable plaques. Such plaques may be stable for long times but upon rupture initiate clot formation that can obstruct blood flow.
The best approach is to prevent or retard the atherosclerotic process during the silent phase of the process and to avoid the unexpected death or urgent treatment that the complications create. Thus the preventive treatment is best initiated when the person has not complaints but risk factors for atherosclerosis are identified. While all risk factors should be addressed, the focus is on raised blood cholesterol..
If the cholesterol level is not too high, lifestyle changes (correct diet, sufficient exercise, and smoking cessation) may be enough to retard or arrest the process and reduce the risk. After these measures are taken for a few months, a follow-up evaluation of all the risk factors and cholesterol must be done.
The patient must also be made aware that the improvement will only remain while the lifestyle changes remain, and that as soon as old habits are resumed, the cholesterol levels will return to what they were before.
If blood levels are too high, then medication of various sorts may be used. These work in different ways to lower blood cholesterol. Absorption can be impaired by dietary fibre, binding of bile salts, blocking the uptake of cholesterol in the bowel (plant sterols and ezetimibe). The contribution that synthesis of cholesterol in the liver makes can be lowered by statins.
This induces a greater importation of cholesterol from the blood and thus the blood level decreases. Lowering blood cholesterol after a complication is also important to prevent more future events.
The rupture of a plaque may not be noticed when a small clot forms and the blood flow to the organ remains normal. If incomplete blockage of arteries results in problematic angina pectoris or places the heart at risk of severe damage (e.g. a narrowing near the origin of the large left (main stem artery), the diseased arteries may be bypassed surgically and a "detour" placed to carry adequate blood passed the narrowing or the arteries may be opened with a balloon on a catheter (angioplasty) and the placing of stent.
Blockages in the arteries to the brain (carotid arteries) may be also be opened by bypass surgery or a stent in order to prevent strokes.
Medication vs surgery for angina
This decision is best made by a cardiologist and is based on clinical and investigational findings.
If your symptoms are relatively mild, they may improve with lifestyle changes which definitely have a significant impact in the long term. The drugs for angina pectoris are designed to either reduce your heart’s demand for oxygen, or to allow your blood vessels to relax and widen so that more blood can be supplied.
If you smoke, you must stop immediately. You should also look carefully at your diet – preferably with the help of a dietician – and cut down on fats, lose weight and do supervised exercise.
But some people are not helped by these relatively simple measures. The next step is to perform an investigation that outlines the coronary arteries (angiography). The catheter through which the dye is injected is inserted into the groin and then advances to the heart.
This procedure assesses whether there are critical narrowing that require repair (angioplasty possibly to place a stent to sustain patency) or surgery to bypass a diseased region with one of the less needed arteries in the chest, forearm or a vein from the leg.
For many people angioplasty offers a safe and relatively easy way to deal with blocked arteries. The procedure is called percutaneous transluminal coronary angioplasty (PTCA). This means a procedure which goes through the skin, inside a coronary blood vessel, to repair that blood vessel.
A hollow tube called a catheter is inserted into an artery in the groin. The area will have been numbed first with local anaesthetic. A thinner catheter is then inserted through the first catheter. This has a miniature, deflated balloon at its tip.
The cardiologist is able to watch the position of the catheter using X-ray images on a television screen. The catheter is guided through your arteries until it arrives at the blocked artery in your heart.
This is carefully threaded through the blockage. Once in position, the balloon is inflated. This widens the artery and improves the flow of blood through the area. The balloon is then deflated and removed. The different procedures take between 30 minutes to two hours and often only require one day in hospital.
Coronary angioplasty is done under local anaesthesia and is generally no more than mildly uncomfortable. The different procedures take between 30 minutes to two hours and often only require one day in hospital.
Stents after PTCA
In around 80% of patients, a stent is also used after PTCA. A stent is a mechanical device which is used to keep a hollow tube open. A coronary stent looks like a coiled spring. It is inserted into the artery using a catheter.
This improves the outcome of the whole procedure, making sure that the formerly blocked artery remains open. Before stents were developed there was a chance that the blocked artery would narrow again – called restenosis.
A stent is intended to remain in place permanently to keep the artery open. It is inserted under high pressure and over time actually becomes incorporated into the wall of the artery, so there is no danger of it moving later.
Bare metal stents may, however, also become obstructed with clot or growing cells. This is why drugs such as clopidogrel are prescribed for a long period after placing of a stent or a drug-eluting stent is used to suppress this process.
But there are risks involved in the use of drug-eluting stents: the potent anticlotting medication prescribed to the patient after insertion of a drug-eluting stent may lead to uncontrolled bleeding, particularly if the patient is involved in a road accident or suffers severe physical trauma.
Take special care to get the patient to an emergency unit as soon as possible if there is any serious injury or bruising and bleeding.
What about bypass surgery?
It used to be the case that the only option available to blocked coronary arteries was coronary artery bypass surgery. However, newer techniques (angioplasty and stents) have replaced the coronary artery bypass graft (CABG) in around half the people with blocked coronary arteries.
A bypass is a major operation. An artery from your chest wall or a vein from your leg is attached (grafted) to the aorta to conduct blood passed the blocked part of your coronary artery. This allows your heart muscle to receive enough blood flow to provide oxygen and nutrients. The cost is generally higher than angioplasty, and it requires a fairly long stay in hospital.
However, for some people with blockage of many of the arteries of their heart, it remains the only option. Generally, people with diabetes or blockages in certain places also do better with surgery.
What are the advantages of angioplasty?
For many people, coronary angioplasty is as effective as bypass surgery in reducing chest pain and improving your ability to live a normal life. However, it has not yet been proved that either angioplasty or for that matter, bypass surgery, actually prolong life except in some specific circumstances.
In spite of this, the technique is so much more effective than drugs in relieving symptoms, that it is preferred in many cases. Angioplasty offers around a 98% immediate success rate.
Recovery from the procedure is quick, relatively pain free and much less expensive than bypass surgery.
What are the disadvantages of angioplasty?
In around 10 to 15% of people, the artery opened with PTCA re-narrows within six months. It is more likely to narrow again if the blockage was very long or was in a very small artery. The good news is that angioplasty can be repeated, but in some patients bypass surgery will be recommended if this occurs.
Some cardiologists tend to add stents till the patient’s medical aid will no longer pay for any more stents. Some patients end up with more than 10 stents. This may not be wise. .
The chances of suffering a heart attack or needing an emergency bypass during coronary angioplasty are less than 2%. The risk of dying during the procedure is much less than one percent.
New research shows that the initial higher success rate of angioplasty evaporates after about two years - after two years the survival rates are no better than with bypass surgery.
Is angioplasty for you?
When you have chest pain and problems with daily life which are not being relieved with medication, you will normally be sent to see a cardiologist. He or she will then assess the different treatment options open to you.
You will have a coronary angiogram, which is a technique in which a dye is injected into the arteries of your heart. This allows the cardiologist to see exactly where and how severe blockages in your arteries are.
Around half the people who have blocked coronary arteries are offered angioplasty. The rest are better treated with bypass surgery. Diabetic patients often do better with coronary artery bypass grafting and there are instances when technical difficulties make bypass surgery the better option.
Even relatively mild angina which is controlled by medication can be relieved by angioplasty. It is a question of weighing up the risks, benefits and costs of this procedure rather than remaining on medication and altering your lifestyle.
Remember that lifestyle changes must be made even after angioplasty or bypass surgery. In particular, you must never smoke again.