Study finds no advantage in newer way to perform heart bypass

NEW YORK — It seemed like a great idea: doing bypass surgery while the heart is beating, sparing patients the complications that can come from going on a heart-lung machine. The first big test of this method has produced a surprise: Bypass has fewer problems and is more successful done the old way.

Most surprisingly, there were no signs of mental decline in those on the machines. Avoiding this problem was thought to be one of the benefits of "off-pump" surgery.

"For the vast majority, there's no advantage to doing it off-pump and there may be some disadvantages," said Dr. Frederick Grover, of the University of Colorado, Denver, one of the leaders of the study.

Heart bypass is believed to be the most common surgery in the world; an estimated 253,000 Americans have the operation each year. Traditionally, the surgery is done while the patient is hooked to a heart-lung machine, which takes over the job of circulating blood while the heart is stopped. That "on-pump" method makes it easier for surgeons to attach new arteries or veins to create detours around clogged arteries.

But the heart-lung machine carries a small risk of complications, including stroke. In the 1990s, surgeons began doing off-pump surgery, without the machine but with devices that stabilize the beating heart.

Today, about one in five bypasses are done off-pump, and it's been debated which is better.

The research reported in the new issue of The New England Journal of Medicine is the largest to compare the two techniques in a rigorous manner. The study involved 2,203 patients at 18 Veterans Affairs medical centers.

About half were randomly assigned to bypass surgery with a heart-lung machine, half without. A month after surgery, there was no difference in the number of deaths or other complications in the two groups.

But a year later, the off-pump group had worse outcomes. About 10 percent had either died, had a heart attack or needed another bypass or procedure to open a blocked artery, compared with about 7 percent of the on-pump group.

Also, the off-pump group got fewer artery detours than originally planned and fewer of their bypasses were open after a year, about 83 percent versus 88 percent for on-pump.

Some patients were given mental tests before surgery and after a year; there was no mental decline in either group.

Dr. Eric Peterson, a heart doctor at Duke University Medical Center who wrote an accompanying editorial, said it was "a remarkably well-done study" but won't end the debate.

The VA study was mostly men who were younger and healthier than the typical bypass patient, Peterson noted.