Features July 2009 Issue

Know the Risks and Benefits of Stents and Bypass Grafts

Recent research suggests diabetes should be among the many factors considered when deciding which procedure is best for you.

Several criteria must be considered in deciding whether your blocked coronary arteries are treated with bypass surgery or with stents. The size and location of the blockages are perhaps the greatest determining factors, but a recent study suggests that age and diabetes should be part of the equation, too. A study of more than 8,000 heart patients, published in the March 19 issue of The Lancet, found that those patients with coronary artery disease (CAD) who were 65 and older or who were diabetic fared better after bypass surgery than stenting.

In a coronary artery bypass graft, a blood vessel from another part of the body is grafted onto the aorta and to a point on a blocked artery, just below the blockage, to improve blood flow to the heart muscle.

Cleveland Clinic cardiovascular surgeon Marc Gillinov, MD, suggests, however, that age doesn’t significantly raise the risk for either approach. "Both procedures are very safe," Dr. Gillinov says. "Most studies show that patients with diabetes have superior long-term outcomes with bypass surgery if they have three-vessel disease."

He adds, however, that three-vessel disease or left main coronary artery disease is typically treated with bypass surgery anyway and that single- or double-vessel disease may be best treated with stents, again depending on all factors. Multi-vessel disease refers to blockages in more than one of the coronary arteries—the blood vessels that supply the heart muscle with oxygen-rich blood.

Stents and Bypass Surgery

While bypass surgery remains the gold standard for treating CAD, the use of bare-metal and drug-eluting stents has risen in recent years as the technology has improved and longer-term study results have been gathered.

By its nature, open-heart bypass surgery is a much more invasive procedure, usually requiring a heart-lung machine (though advances continue to allow for more "off-pump" procedures) and a much longer recovery after the operation.

Stents can be placed in the blocked arteries with a catheter from the groin or forearm, but their main purpose is to relieve chest pain (angina). Stents tend not to have the long-lasting effects of bypass surgery and are not used to treat heart attack patients with major CAD or prevent heart attacks in CAD patients.

Stents also tend to require more follow-up procedures than bypass surgeries, though Dr. Gillinov notes that subsequent stent implants do not usually impose hardship on patients, since the procedures are much less-invasive than open-heart surgeries.

"The reinterventions that occur are usually repeat stenting, and they’re generally well-tolerated," Dr. Gillinov says.

After the Interventions

A study of 1,800 patients with blockages in their left main coronary artery or three major heart arteries, published in the March 5 issue of the New England Journal of Medicine, found that among those who had stents 17.8 percent had major adverse cardiac or cerebrovascular events (such as strokes), compared to 12.4 percent of those who had bypass surgery.

"It’s somewhat higher, but not that much higher," Dr. Gillinov says. "The numbers of strokes were small in the study. The strokes likely result from either manipulation of the aorta or use of the heart-lung machine. Overall, the risk of stroke is low. Special pre-operative studies can help reduce the risk of stroke by identifying those at risk; these include a CT (computed tomography) scan of the aorta and screening of the carotid arteries by ultrasound."

The bottom line is that you and your doctor should discuss all options for your particular condition. And regardless of what procedure is used, you’ll need to make healthy choices to help ensure that the work you have done will have the best chance of helping you meet your treatment goal.

"After either procedure, patients need to adjust their lives and lifestyles to enhance the procedure’s durability," Dr. Gillinov says. "They must have a heart-healthy lifestyle and diet."