Two Ways to Keep the Blood Flowing
Coronary artery bypass surgery, which former President Clinton is scheduled to undergo, is often the treatment of choice for heart patients who have extensively clogged arteries or for those who are relatively young and desire a more maintenance-free procedure, experts said Friday.
Angioplasty, the alternative procedure in which a balloon is inflated in the clogged artery to compress the blockage and restore blood flow, often needs to be repeated sooner and the quality of life after surgery may not be as good, said Dr. Randy Chitwood of the East Carolina University School of Medicine. He is the head of the American College of Cardiology’s cardiovascular surgery committee. Chitwood himself had bypass surgery 10 years ago.
“The mortality of the two procedures is about the same, but with angioplasty, multiple interventions often need to be done to maintain survivability,” he said. With bypass, “there is less chance of being back on the [operating] table, less maintenance and fewer episodes of chest pain.”
When the coronary arteries that supply nutrients and oxygen to heart muscles become clogged with plaque, usually as a result of high cholesterol levels, either a bypass or angioplasty may be needed. When the arteries narrow 50% to 70%, there isn’t enough blood to meet the heart’s increased oxygen demand during exercise, producing the chest pain known as angina.
When the blockage exceeds 90%, the patient has pain even at rest. A blood clot formed at the site of the narrowing can then cause a heart attack, in which heart tissue begins to die from lack of oxygen.
In bypass surgery, a blood vessel from elsewhere in the body is used to carry blood around the restricted area. Historically, surgeons used a section of the saphenous vein from the leg as a replacement.
In recent years, however, most have switched to the internal mammary artery from the chest because it is less likely to become clogged. Ten years after surgery, about 66% of saphenous veins remain open, in comparison with 90% of mammary arteries.
The primary exceptions are when the diseased area is too large for the relatively short mammary artery to be used and when the surgery is performed in an emergency. It also takes longer to remove the mammary artery.
Typically, the patient is placed on a heart-lung machine that keeps blood circulating while the heart is stopped so that the new vessel can be attached. Some physicians now perform a so-called beating heart procedure in which the vessel is attached while the heart is still pumping blood.
It was originally thought that patients undergoing a beating heart procedure were less likely to have a stroke or neurological damage, but recent studies have shown that that is true only for the oldest patients, Chitwood said. Either way, in the hands of a practiced surgeon, the operation takes about 4 hours -- with more than half that time devoted to opening and closing the chest.
According to data from the National Center for Health Statistics, about 500,000 bypasses are performed each year. That number has declined in the last four years as the number of angioplasties has grown to about 550,000.
After the surgery, according to updated guidelines issued this week by the American College of Cardiology, all patients should receive aspirin to minimize clot formation, cholesterol-lowering statins and blood-pressure lowering beta-blockers.
The normal length of the hospital stay after bypass surgery is five or six days, but patients often report feeling substantially better after two or three. Full recovery takes a couple of weeks. Chitwood said he was operating again within a month.
The mortality rate is 3% to 4%, generally as the result of a heart attack. Stroke occurs in 1% to 2% of cases, primarily in the most elderly patients. The younger a patient is, the more likely they are to come through with flying colors, Chitwood said, and Clinton, at 58, is still young.
