| WHAT IS CORONARY ARTERY DISEASE? |
In the normal heart, arteries arising from the aorta travel over the surface of the muscular pumping chambers. These arteries branch repetitively supplying the heart muscle with oxygen and nutrients.
Normal arteries have a thin layer of lining cells (the endothelium) and a middle muscular layer which can contract or dilate to change blood flow.
Repeated injury to the lining cells (endothelium) due to smoking, high cholesterol, diabetes, hypertension, inheritance, or inflammation results in a process called atherosclerosis ( hardening of the arteries or coronary artery disease).
Atherosclerosis is an inflammatory condition of the arteries which results in narrowing of the arteries which can reduce blood supply to the heart muscle.
Narrowed coronary arteries can cause chest pain, shortness of breath, and limitation of exercise capacity. However, some areas of narrowing ( plaque ) are soft and unstable and may crack or split open. These vulnerable or unstable plaques are dangerous and may cause acute clot formation in the artery which may abruptly stop blood flow to the heart muscle causing heart muscle damage (heart attack). Modern medicines help to stabilize these vulnerable plaques thereby reducing heart attack and stroke. |
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| HOW IS CORONARY ARTERY DISEASE DIAGNOSED? |
Unfortunately, about ½ of patients find out they have coronary disease when they have a heart attack without warning.
Warning symptoms of chest pain (rest or exercise) shortness of breath, or fatigue may occur.
Early diagnosis is best using stress and imaging methods when symptoms or risk factors raise concern. |
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| HOW IS CORONARY ARTERY DISEASE DIAGNOSED? |
- Stress echocardiography
- Nuclear stress testing
- 64 slice CT angiography
- Coronary angiography
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| WHAT ARE MY TREATMENT OPTIONS? |
A healthy lifestyle is essential to reducing the risks of coronary artery disease:
- healthy eating
- regular aerobic exercise
- no smoking
- treatment of hypertension, blood pressure, cholesterol, and diabetes
- weight control
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| WHAT ARE MY TREATMENT OPTIONS? |
| MEDICAL THERAPY
Although medicines like nitroglycerine for relief of chest pain are well known, modern medical therapy is given to reduce the adverse outcomes of heart attack, stroke, heart failure, and arrhythmia. 3 groups of medicines are recommended to all patients with arterial disease.
ANTI-PLATELET DRUGS (aspirin, clopidigrel)
ACE INHIBITORS / ARB
STATIN CHOLESTEROL MEDICATIONS (Beta-blockers are also indicated after heart attack, for reduced blood supply, and heat failure)
BYPASS SURGERY
Bypass surgery uses veins from the leg or an artery in the chest to restore blood flow by going around blockages.
Bypass surgery has been proven to be more effective than medicines alone in certain types of severe coronary blockages. For example: blockages of all three main arteries, blockage of the left main artery, blockage of specific large arteries, in diabetics with blockage of the artery to the front of the heart. This type of surgery is external to the plaques and is therefore not limited by the internal features of the artery.
CORONARY ARTERY STENTING
When severe coronary blockage is suspected due to a heart event or testing, coronary arteriography (or angiography) is often recommended.
This minimally invasive test is performed in the hospital in a catheterization laboratory. After the patients is covered and the groin area skin prepared, a small tube or catheter is inserted through a small nick in the skin at the groin.
CORONARY ARTERY STENTING
The treatment of coronary blockages depends on the number, severity, location, and vulnerability of plaques.
Coronary arteriography is a low risk procedure which clearly answers these questions about the disease which non-invasive testing cannot. Physical or mechanical treatments of plaques by open heart surgery or stenting require coronary angiography to define the plaque location, severity, and stability features.
Balloon angioplasty (PTCA) is a method of opening narrowed coronary arteries using catheters in the catheterization laboratory. Balloon angioplasty has been shown to be equally as effective as bypass surgery in some situations. Plaque is part of the artery and does not break away; it is pushed out or displaced.
However, problems with acute blockage and re-narrowing after angioplasty have resulted in this procedure being replaced in most situations by coronary artery stenting, a safer more effective treatment.
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| WHAT ARE CORONARY ARTERY STENTS? |
Angioplasty ( PTCA) balloons are mounted on the ends of tiny catheters which are advanced from the inside of larger catheters into the coronary arteries. After inflation and deflation of the balloon, the catheter is removed. Today the PTCA or balloon procedure is often done first to open the artery enough to permit passage of the stent catheter.
The stent is a cylinder made of stainless steel which looks like a rolled piece of chain-link fence. The stent expands to hold the artery open and remains imbedded in the arterial wall. The balloon is then removed. The procedure is safer than PTCA (balloon angioplasty) because the plaque is held back and stabilized. Stents reduce the chance of re-narrowing (re-stenosis) compared to PTCA. |
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| HOW DO STENTS WORK? |
| A stent is crimped on a deflated balloon. The stent is expanded by balloon inflation. The balloon is then removed leaving the stent artery widely open pushing the plaque away. |
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| WHAT ARE DES? (DRUG ELUTING STENTS) |
Stents are a better treatment than balloons alone (PTCA) due to lower procedure risk, less artery splitting, acute blockage, or urgent surgery. Stents give a better opening and less chance of re-narrowing over time.
However, stents heal by the growth of lining cells over the metal. In 10-20% of patients, this normal tissue growth is excessive and may cause narrowing inside the stent.
Drug coated (drug eluting, or medicated) stents have been developed to reduce lining cell growth inside the stent which may reduce blood supply.
Stents are lightly coated with a polymer which is impregnated with a drug which inhibits cell growth (paclitaxel or sirolimus). Like a Tic-Tac, the drug is slowly released thereby reducing re-narrowing.
A very large number of scientific studies have shown that drug eluting stents greatly reduce the chance of re-narrowing and the need for repeat treatments to restore blood supply. This benefit occurs for all categories of narrowed coronary arteries: large and small, single or multiple, long or short, and in all types of patients including diabetic patients.
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| WHICH TREATMENT IS BEST FOR ME? |
All of us should live a healthy lifestyle
Every patient with coronary artery disease should be treated with aspirin, a statin cholesterol medicine, and an ACE or ARB unless side effects limit use (as can occur for any medication). Medicines are needed with all other treatments
There is no cure for coronary artery disease and heart attack and its complications can occur with surgery, with medicines or with stenting.
Coronary artery bypass surgery and coronary artery stenting are physical or mechanical treatments for a mechanical problem = narrowing of the artery. The best treatment therefore depends on the type of narrowing. In some situations, bypass surgery is best and stenting ill advised----and vice versa. For many patients, these treatments are not needed.
In our program, 20 years of experience spanning the improvement of bypass surgery, the development of PTCA and stenting, and extensive experience with new stress imaging helps us to provide an integrated and safe approach to your testing and treatment. |
