With the help of medications, most patients with coronary artery disease can live normal lives that have few limitations. However, some patients benefit from procedures that restore blood flow to areas of the heart muscle that have been affected by a blocked artery.

The two main procedures are angioplasty—which is performed by cardiologists—and coronary artery bypass graft surgery (CABG)—which is performed by heart surgeons. These procedures can relieve angina and improve life expectancy, but they also carry a small risk for heart attack, stroke, and other complications, including death.

Therefore, they are generally reserved for patients whose symptoms can’t be adequately controlled with medications and those who are at very high risk for a heart attack. Before you get either an angioplasty or cardiac surgery, your doctor will have to perform a cardiac catheterization.

During this procedure, pictures are taken of blockages in the arteries of your heart. To do this, the doctor will insert a catheter (a thin, hollow plastic tube) into a large artery—usually in your groin, but possibly in an arm or wrist—after you receive local anesthetics. The doctor then moves the catheter along the artery until it reaches your aorta.

The tip of the catheter is pushed up the aorta until it reaches the heart. Then it is gently pushed into the coronary arteries that supply blood directly to your heart muscle. At this point, a contrast dye will be injected through the catheter to help the blood vessels show up better on the x-ray, illuminating whether the artery is blocked or narrowed.

If the cardiologist performing the catheterization thinks the artery is blocked enough to call for an angioplasty, it can be done immediately. If cardiac surgery is required, the heart surgeon will use pictures obtained during the catheterization as a guide.

Angioplasty

As already described, angioplasty starts with the physician inserting a catheter into an artery and guiding it through the blood vessels to the openings of the coronary arteries. Inside this catheter is an even thinner catheter that has an inflatable balloon near its tip.

And inside that catheter is a wire with a soft tip that can snake through tight narrowings and punch through clots but is unlikely to damage the wall of the coronary artery. The cardiologist guides the wire gently down the artery until the tip is beyond the narrowing. (When the coronary artery is completely blocked, the physician may try to push the wire through the obstruction.)

Once the wire has crossed the blockage, the catheter with the balloon slides down the wire until the balloon is adjacent to the atherosclerotic plaque. From outside the body, the physician inflates the balloon, which cracks and compresses the atherosclerotic plaque, stretches the underlying normal arterial wall, and so widens the artery.

When the procedure works well, the vessel remains wide open, and the patient’s angina symptoms are alleviated. However, a relatively common problem is restenosis, a renarrowing of the artery at the same spot. Restenosis usually happens within three to six months of the original procedure.

It is not surprising that it could occur, because an angioplasty is a temporary measure: the balloon expands to squash the plaque and widen the center of the artery, and then the balloon is deflated and pulled out of the body. Nothing is left in place to keep the artery open.

About a decade ago, 25 percent to 35 percent of patients who underwent angioplasty developed restenosis that was so significant that they needed a second procedure. To reduce the chance of restenosis, cardiologists began using a device called a stent.

A stent is small tube made of an expandable metal mesh that is inserted at the area of narrowing and left in place. The use of stents has lowered the restenosis rate to 10 percent to 20 percent, and newer types of stents appear even more effective. Today, more than 70 percent of people who undergo angioplasty have stents inserted.

To place the stent, the doctor uses the same balloon catheter used in angioplasty. The collapsed stent is wrapped over a balloon catheter. When the balloon is inflated at the site of the blockage, the stent also expands and remains expanded even when the balloon inside it has been deflated.

The doctor pulls the balloontipped catheter out of the body and leaves the expanded stent in place. Even after this procedure, a blood vessel can close up again. This usually occurs because of a process called intimal hyperplasia. The atherosclerotic plaque, stimulated by immune system cells in the lining of the artery, starts to grow through the small holes in the wire mesh of the stent.

However, new stents coated with drugs help prevent that from happening. The coating prevents restenosis by stopping the cells lining the vessel wall from vigorously reproducing. Drug-coated stents have been widely available for only a couple of years, but they have already made a huge impact on our treatment of patients with coronary artery disease.

Nowadays, almost everyone who has a stent procedure gets one coated with an immunosuppressant drug. Two different types of coated stents have been approved for use. There have been some manufacturing problems with each of them that can cause rare but serious complications as the stent is being placed in the artery.

The companies that make these stents are working to fix the problem, and there is no reported risk to people who have previously received one of these stents: the rare complications occur only as the stents are being placed in a person’s body. We expect that the manufacturing problems will have been fixed and this risk eliminated.

Following a stent procedure, patients take aspirin—and sometimes other drugs that thin the blood—in order to prevent clotting and, therefore, restenosis. Aspirin must be taken indefinitely, and some patients take another blood thinner for two to four weeks following surgery.

Two commonly used blood thinners are ticlopidine and clopidogrel. Patients need to take these drugs regardless of whether they receive drug-coated stents or the regular, uncoated variety. About one person in five is born with a tendency to resist the blood-thinning effects of aspirin.

Some doctors are now starting to test for such aspirin resistance and are emphasizing the use of other blood-thinning drugs when tests show that a person is aspirin resistant. Other doctors do not believe that the current evidence warrants testing for aspirin resistance or altering the prescription for blood-thinning drugs accordingly.

Coronary Artery Bypass Graft (CABG)

Surgery In coronary artery bypass graft (CABG) surgery, the cardiac surgeon takes a length of blood vessel from elsewhere in the body and uses it to shunt blood around a narrowed or blocked coronary artery. The attached vessel thus permits blood to bypass the blockage so the heart muscle ordinarily supplied by that coronary artery can once again receive nourishment.

About 366,000 Americans undergo CABG surgery each year. The operation can dramatically improve the quality of life and boost life expectancy for some (but not all) people with coronary artery disease.

The latest guidelines from the American College of Cardiology and the American Heart Association recommend that physicians consider CABG surgery when there is a blockage of 50 percent or more in the left main coronary artery, alone, or 70 percent or more in all three other major coronary arteries.

Bypass should be considered in such circumstances even when patients have few or no symptoms of angina. According to the guidelines, a CABG procedure can also be beneficial for patients who’ve had angioplasty but who continue to have symptoms caused by blocked arteries, as well as for patients who’ve already had bypass surgery but suffer from disabling angina.

In CABG surgery, the patient is under general anesthesia, and the surgeon cuts through the breastbone to gain access to the heart. In the conventional approach to bypass surgery, the heart is usually stopped with a solution called cardioplegia so that the surgeon doesn’t have to perform surgery on a heart that’s constantly moving.

A heart-lung machine pumps oxygen-rich blood through the patient’s body, temporarily substituting for the heart. The surgeon takes a vein or an artery from another part of the patient’s body and stitches it into place to reroute blood around the blocked artery.

The replacement vessel might be an internal mammary artery taken from the patient’s chest wall, a radial artery from the patient’s arm, or a saphenous vein taken from the leg. In any case, the artery or vein is a “spare” vessel. The patient will suffer no major ill effects because that piece of artery or vein has been removed.

If the grafted vessel is a vein from a leg or a radial artery from an arm, one end is attached to the aorta and the other is sewn onto the diseased coronary artery, beyond the blockage. When an internal mammary artery is used, the upper end is usually left attached to a large artery called the subclavian artery, and the lower open end is attached to the diseased coronary artery, beyond the blockage.

Artery grafts (particularly the internal mammary artery grafts) tend to last longer than vein grafts, and the use of artery grafts has been shown to prolong life. After the surgery is completed, the patient’s heart is started again, and he or she is taken off the heart-lung machine.

Most people stay in the hospital for four to five days after the operation, though within one to two days of surgery the doctor will probably ask the patient to get up and walk. If you should undergo CABG surgery, you might also be scheduled for a cardiac-rehabilitation program, which you will attend after leaving the hospital.

Cardiac rehabilitation helps you and your heart gain strength. It also teaches you heart-healthy practices that will help protect you from future heart disease, such as observing a low-fat diet and exercising regularly. The latest innovation in CABG surgery is a procedure called offpump bypass or beating-heart surgery.

In this procedure, the operating team doesn’t stop the heart and place the patient on a heart-lung machine. Instead, the surgeon uses special equipment to hold the heart steady, enabling the surgeon to operate on it while it continues beating. The surgeon still splits the entire breastbone but avoids putting the patient on the heart-lung machine.

Off-pump CABG is probably best suited for patients in whom the heart-lung machine may pose important complications such as neurological deficits or kidney failure. By avoiding the heart-lung machine, off-pump CABG was also expected to lower the rate of some complications, such as memory impairment and lessened ability to concentrate.

But a 2002 study in the Journal of the American Medical Association found that after twelve months, patients who had the off-pump procedure were as likely to have suffered memory loss and other cognitive problems as patients who had conventional bypass surgery.

However, with just 281 patients, the study was too small to be definitive. Another key question is whether the beating-heart procedure is as effective as standard coronary artery bypass graft surgery. Results from a recent study at one hospital that regularly performs this operation were encouraging.

Investigators found that outcomes were very good and that they improved over time as the doctors became more experienced. By the last 174 cases in the series, one-year survival rates were excellent. But it’s too early to tell whether survival rates were as good as those of patients who had conventional bypass surgery.

Another paper published in the New England Journal of Medicine, however, suggested that the patency of CABG grafts in off-pump surgery were inferior to conventional on-pump surgery. Many surgeons currently believe that off-pump surgery should be used in selected patients to decrease the risk associated with the heart-lung machine, but should not be the first choice for most patients.