Which Heart Bypass Surgery Works Best?

Heart with EKG printoutFive years after heart bypass surgery, patients whose operation was done using a heart-lung pump lived longer than those whose surgeons didn’t use the device, a new study finds.

Since the 1990s, two different approaches have been commonly used by heart surgeons to perform coronary artery bypass graft operations. Coronary artery bypass creates new routes for blood to flow to the heart because old routes are blocked by plaque in the artery. A piece of blood vessel is taken from another area of the body (often the leg) and used to “bypass” a blocked vessel going to the heart, according to the U.S. National Heart, Lung, and Blood Institute.

The two different ways to do this surgery have been referred to as “on-pump,” assisted by a heart-lung machine, or “off-pump.” Which procedure produces better results has been controversial, the researchers said.

“The heart-lung machine allows you to stop the heart so you can sew the grafts with no blood flowing through it,” said senior researcher Dr. Frederick Grover, a professor of cardiac surgery at the University of Colorado.

This enables the surgeon to work on a heart that is fully exposed and not moving, he said.

When operations are done on-pump, surgeons are able to do more grafts. In off-pump surgery, the heart is a moving target as it continues to pump blood.

This report looks at the five-year outcomes of patients who had heart surgery as part of the U.S. Veterans Affairs trial of on-pump versus off-pump operations done from February 2002 through June 2007.

In this trial, more than 2,200 patients from 18 VA centers were randomly selected to receive either on-pump or off-pump heart surgery. They were assessed a year after their operation and then at five years.

Specifically, the researchers looked for major cardiac problems, including death from any cause, the need for new heart procedures or nonfatal heart attacks.

After a year, more patients who had an off-pump operation died or needed new procedures than patients who had on-pump surgery, Grover said.

Five years after surgery, the rate of death among those in the off-pump group was a little over 15 percent, compared with nearly 12 percent among those who had on-pump surgery, the researchers found.

That’s a 28 percent higher risk of dying five years after surgery for the off-pump group, Grover said.

In addition, more people who had off-pump surgery had major cardiovascular problems than those who had on-pump operations — 31 percent versus 27 percent, he said.