Bypass or angioplasty with stenting: How do you choose?

It's your doctor's call, but it's good to understand, and to weigh, your options.

Your heart doesn't just pump blood—it needs blood to survive. So, when blocked coronary arteries threaten the heart's blood supply, something must be done.

There are two main approaches.

Angioplasty plus stenting. A small balloon wrapped in a collapsed wire mesh stent is inserted into a blood vessel in the groin or arm and maneuvered into the heart. When the balloon is inflated, it flattens the cholesterol-filled plaque that has been restricting blood flow through the artery. When the balloon is deflated and removed, the stent remains behind to prop open the artery. This is called balloon angioplasty with stenting.

Coronary artery bypass graft (CABG). During open-heart surgery, an artery or vein taken from elsewhere in the body is stitched in place to reroute blood around the blocked artery.

Which is best? It's not a toss-up. But the right choice depends on a number of factors, says Harvard revascularization expert Dr. Donald E. Cutlip, a surgeon at Beth Israel Deaconess Medical Center.

"The question of stent versus bypass surgery is really for those patients who have multivessel disease involving all three coronary arteries," Dr. Cutlip says. "This accounts for about a quarter to a third of patients with coronary disease."

And this question has an answer—bypass surgery—as long as the individual's surgery risk isn't too high.

"For three-vessel coronary disease, bypass now has been shown to be superior to stenting, with the possible exception of some cases in which the narrowing in the artery is very short," Cutlip says. "But by and large the debate is settled that bypass surgery is better."

CABG best for most important artery

The heart's three coronary arteries are not all equal. The most important artery is called the left anterior descending artery (LAD). It feeds blood to the whole front wall of the heart, which represents much more muscle than the area fed by either of the other two coronary arteries. A narrowing or blockage in the LAD is more serious than narrowing or blockage in the other arteries.

Bypass surgery usually is the best choice for a blocked LAD. If the LAD is not blocked, and there are no other complicating factors, stents are more likely to be used, even if both of the other arteries are blocked.

"If you have two blocked vessels and one is the LAD, especially the upstream portion, the data support bypass surgery, but not as convincingly as for the patient with three-vessel disease," Cutlip says. "There are issues like whether both vessels can be easily treated with stents, or whether the patient has other risk factors."

One major factor is that LAD bypass uses another artery—the mammary artery, located in the chest near the heart—for the graft. Complications are rare, and CABG using the mammary artery lasts for decades. Moreover, for reasons still unknown, the mammary artery is nearly immune to blockage.

"If put you put a stent in the LAD, you are only protecting that area of blockage, and the rest of that artery is still vulnerable," Cutlip says, "whereas a bypass will protect the downstream portion of that vessel probably forever."

When stents are best

When the LAD isn't involved, stents are usually the first choice.

"If you're talking about blockages in one or even two vessels, the talk with the patient is not so much about bypass versus stenting as about stenting versus medical therapy," Cutlip says. Medical therapy here means medication and follow-up visits with your cardiologist, but no invasive interventions such as bypass or angioplasty.

There's another time stents are the best choice: when bypass no longer is an option.

While LAD repair with a mammary artery usually lasts for the rest of a person's life, CABG grafts in the other two arteries do not. These procedures typically use veins rather than arteries, and in half of people, these repurposed veins start to fail after eight to 10 years.

"Once that happens and you need more work, a second bypass can be done, but generally we prefer to use stents," says Dr. Cutlip.

CABG best for patients with diabetes, other factors

For people with diabetes, there are fewer questions regarding the choice between bypass surgery and stents. Bypass surgery is generally superior to angioplasty.

When more than one heart artery is blocked, CABG may also offer better survival rates for people with heart failure.