If you have clogged coronary arteries that restrict the flow of blood to your heart, should you have bypass surgery or an angioplasty procedure to open the blocked vessel?

Sometimes, the answer is neither.

“Not all blockages are life-threatening,” says Patrick Simpson, M.D., an interventional cardiologist with Pinehurst Medical Clinic. “When someone has coronary arteries that are less than 50 percent blocked, we generally don’t fix those. The heart can do extremely well for a long time until a vessel is about 75 percent closed.”

If patients have artery blockages of more than 50 percent but less than 75 percent and have symptoms such as chest pain, they might or might not require surgery or angioplasty, depending on whether their symptoms are stable.

“If they only have chest pain when they are exerting themselves, and if the pain isn’t increasing in either frequency or severity, then we can treat them with medicine,” says Dr. Simpson. “The findings of a major study released earlier this year confirmed these patients can do just as well in the long run on medication as they would if we put in a stent.”

(A stent is a metal scaffold that, during an angioplasty procedure, is inserted into an artery to hold it open after the blockage has been cleared away. The clearing is done by a balloon that compresses the plaque against the wall of the artery.)

Patients with moderate blockages who don’t require an interventional procedure are typically given drugs to lower the amount of cholesterol in their blood, as well as blood thinners to reduce the risk of clots. These patients may continue to have chest pain during physical activity.

“But if the pain goes away quickly when they stop to rest or when they take nitroglycerin, they can do just fine,” Dr. Simpson says.

Nitroglycerin dilates the veins throughout the body, allowing them to hold more blood. This reduces the volume of blood returning to the heart, so the heart becomes a little smaller. It doesn’t have to work as hard or need as much oxygen, and with less strain on the heart, there is less pain.

People who have moderate coronary artery blockage—between 50 percent and 75 percent—and whose symptoms become more frequent or severe may need more than medication. They often need either balloon/stent angioplasty or bypass surgery.

Sometimes, even people whose coronary arteries are more than 75 percent blocked do not need an interventional procedure if their symptoms are stable and not severe. It often depends on the location of the blockage, Dr. Simpson says.

“If the blockage is out at the tip of the vessel, it is very unlikely to kill you,” he says. “But if it’s at the top of the vessel, near the heart, much more of the heart is at risk and we are more likely to want to fix that.”

According to the current standards of the American Heart Association, a physician shouldn’t necessarily fix a blocked vessel, even if it appears to be severe, as long as the patient doesn’t have worsening symptoms. The physician can just watch and wait until the symptoms become unstable.

Patrick Simpson, M.D.

Dr. Simpson says he is generally comfortable with that approach unless the blocked artery is the one that carries blood to the front wall of the heart. A severe blockage in that artery is most likely to cause a fatal heart attack.

Regardless of what the medical literature says, most patients with severely blocked arteries want them fixed, even if their symptoms aren’t getting worse, Dr. Simpson says.

“If I tell you that you have a 90 percent blockage in a coronary artery but because your symptoms aren’t bad I don’t recommend fixing it, you probably won’t be able to live your life without being constantly worried about your heart,” he says. “So, going ahead and fixing it is often a very reasonable thing to do so the patient can get on with life.”

If a blocked coronary artery needs to be fixed, the options are balloon/stent angioplasty and bypass surgery. A bypass involves grafting a section of vessel from another part of the body onto a coronary artery and literally bypassing the area of blockage.

“Bypass surgery is a time-tested procedure that is good for people who have multiple blockages, particularly if they want to have freedom from other interventional procedures for a long time,” says John Streitman, M.D., a cardiac surgeon with Pinehurst Surgical.

Patients who have several blockages in the same artery, as people with diabetes often do, also tend to be good candidates for a bypass.

Bypass surgery often is the best choice when the patient needs some other type of heart surgery such as valve repair or treatment for atrial fibrillation.

“Probably at least half of the operations we do are more than routine coronary bypass,” Dr. Streitman says. “One reason the number of surgeries we do is going up is because we are doing more valve surgery. The baby boomers are hitting their sixth decade, which means the segment of the population that gets coronary artery disease as well as valvular disease is getting larger.”

Bypass surgery is the only option in cases where, because of the location or nature of the blockage, an artery can’t be opened with a balloon and stent. Likewise, not every blockage can be bypassed. Surgeons can work on most of the heart, but it is particularly difficult for them to bypass an artery on the lower left side.

If the wall of the blocked artery has become hardened with calcium deposits, a bypass might not be possible.

“It’s like trying to sew into an eggshell,” Dr. Simpson says.

In such cases, balloon/stent angioplasty may be the only choice.

Cardiologists and cardiac surgeons have to consider many factors and sometimes complex sets of variables in deciding how best to treat patients with clogged coronary arteries that are keeping the heart from getting as much blood as it needs.

“Medical science can tell us what to do for 10,000 people with a disease, but the trick is taking that knowledge and applying it to a single patient,” Dr. Simpson says. “Each individual case requires an individual decision, and it comes down to what the patient in consultation with their physician believes is the best treatment for them.”