Coronary Artery Disease: Angina and Heart Attack

Coronary Artery Disease (CAD) is the most common type of heart disease and occurs when the arteries that supply blood to the heart muscle (coronary arteries) become hardened and narrowed. When blood flow and oxygen supply to the heart are reduced or cut off, you can develop either angina or heart attack. Angina is chest pain or discomfort that occurs when your heart is not getting enough blood. A heart attack happens when a blood clot suddenly cuts off most or all blood supply to part of the heart. Cells in the heart muscle that do not receive enough oxygen-carrying blood begin to die. This can cause permanent damage to the heart muscle. It is also known as Myocardial infarction or MI, Acute myocardial infarction or AMI, Acute coronary syndrome, Coronary thrombosis or Coronary occlusion. Myocardium is a part of the heart muscle and as it may die (infarct) it is called myocardial infarction (MI).



As per the NHLBI website, each year, more than a million persons in the U.S. have a heart attack and about half (515,000) of them die. About one-half of those who die do so within 1 hour of the start of symptoms and before reaching the hospital. When a heart attack is suspected it is better to obtain emergency help than to wait.

Risk Factors for Heart Attack

Are you at risk for Heart Attack?

There are risk factors for coronary artery disease that you cannot change and risk factors that you can change. According to NHBLI, the risk factors you cannot change include:

Your age:
Men: over age 45
Women: over age 55

Having a family history of early heart disease
Heart disease diagnosed in father or brother before age 55
Heart disease diagnosed in mother or sister before age 65

Having a personal history of coronary artery disease Angina

A previous heart attack
A surgical procedure (angioplasty, heart bypass) to increase blood flow to your heart.

Risk factors that you can change include:

Smoking
High blood pressure
High blood cholesterol
Obesity
Being physically inactive
Diabetes (high blood sugar)

What is the treatment for heart attack?

Medical procedures to diagnose and treat heart disease include coronary angiography, coronary artery bypass grafts, coronary angioplasty, coronary stenting, heart transplants, operations for congenital defects, surgery for heart valve defects, electrophysiological treatments and implanting of cardiac defibrillator

The main treatments include one or more of the following:

Thrombolitic drugs: These drugs are used to dissolve blood clots that have formed in certain blood vessels

Angioplasy: This is the procedure to open up a clogged artery. Usually a stent is used.

Coronary artery bypass surgery: This is done by placing arteries or veins from other areas of your body to bypass the blocked artery.

Medical treatments to control blood pressure and cholesterol may also be essential components of continued therapy.

Bare metal and drug eluting stents to treat clogged arteries

What is a Stent?
A stent is a small, lattice-shaped, metal tube that is inserted permanently into an artery. It holds open an artery so that blood can flow through it, when it has become narrow due to plaque build up on the inner wall of arteries (atherosclerosis).

Arteries carry blood from the heart to organs, and veins carry blood from organs back to the heart. When blood vessels narrow, the flow of blood is slowed or blocked.

How does a stent work?
The stent acts as a scaffold, remaining in place permanently to help keep the artery open. The stent is collapsed to a small diameter and put over a balloon catheter. It's then moved into the area of the blockage.A stent is inserted through a main artery in the groin (femoral artery) or arm (brachial artery) and threaded up to the narrowed section of the artery with a tiny catheter (balloon catheter). Click here to see some pictures showing this procedure. When it reaches the right location, the balloon is slightly inflated to push the plaque out of the way and expand the artery (balloon angioplasty). Some stents are stretched open by the balloon at the same time as the artery. Other stents are inserted into the artery immediately after the angioplasty procedure. Once in place, the stent helps holds the artery open so that the heart muscle gets enough blood.

Can there be problems associated with stent placement?
There can be complications associated with stent placement. The procedure can cause infection, blood clots, or bleeding. Other rare complications of coronary stents include chest pain, heart attack, or tearing of the blood vessel. The stent can move out of place (stent migration).

What are drug-eluting stents?

In some cases, plaque can reappear in the stented artery (in-stent restenosis) leading to reclosure of the artery. Restonosis is reported in about 25% of those who get bare stent placements. However, this complication has been drastically decreased by the use of a new-generation stent called Drug Eluting Stent (DES), also called coated or medicated stent. Drug-eluting stents are coated with drugs that are slowly released and help keep the blood vessel from reclosing. These newer drug eluting stents have shown promise for improving the long-term success of this procedure.

One of these stents, the Cypher, stent is coated with sirolimus (also called rapamycin), which is slowly released into the artery for about 30 days after implantation. Sirolimus is a drug that inhibits cell growth and division, as well as T-cell activation and proliferation. T-cells are components of the white blood cells that take part in the initiate an inflammatory response that commonly follows implantation, and inflammation can lead to restenosis.

Another FDA approved stent is TAXUS™ from Boston Scientific. This is paclitaxel or taxol-eluting stent. This drug also stops cell growth and proliferation.

After stenting what?

According to American heart Association, "patients who've had a stent procedure must take one or more blood-thinning agents. Examples are aspirin and clopidogrel. Aspirin is used indefinitely; clopidogrel is used for one or more months (depending on the type of stent) after the procedure. Clopidogrel can cause side effects, so blood tests will be done often. If you are taking this medication, it is important that you don't stop taking it without consulting your doctor. For the next four weeks a magnetic resonance imaging (MRI) scan should not be done without a cardiologist's approval. But metal detectors don't affect the stent".

They may have to change their dietary habits and exercise according to the Cardiologists instructions.