Stephanie Nano, AP
It seemed like a great idea — doing bypass surgery while the heart is still beating, sparing patients the complications that can come from going on a heart-lung machine. Now 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 be one of the benefits of so-called “off-pump” surgery without a machine.
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 up to a heart-lung machine which takes over the job of circulating blood while the beating heart is stopped. That “on-pump” method makes it easier 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 hotly debated which is better. Earlier, small studies have suggested outcomes were about the same, or gave a slight advantage to off-pump. The debate got attention when former President Bill Clinton had quadruple bypass with a heart-lung machine in 2004.
The research reported in Thursday's New England Journal of Medicine is the largest to date 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 to about seven percent of the on-pump group.
Also, the off-pump group got fewer artery detours than originally planned and fewer of their bypasses were still open after a year – about 83 percent versus 88 percent for on-pump.
“We always have the idea that less is more — less invasive or less anything seems to be a better answer. That isn't always the case,” said Dr. Eric Peterson, a heart doctor at Duke University Medical Center.
Previous research has suggested that women, the elderly and those with other illnesses may do better off-pump. The VA-funded study was mostly men who were younger and healthier than the typical bypass patient.