Bypass surgery safer using heart-lung pump: study

BOSTON (Reuters) - Allowing the heart to keep beating during coronary bypass surgery is riskier than stopping the heart and using a heart-lung machine to keep the patient alive, researchers reported on Wednesday.

Doctors at 18 Veterans Affairs medical centers found that fewer bypass grafts were completed and the one-year risk of heart attack, death, or further heart surgery was increased if surgeons worked on a heart that remained beating.

The technique, involving mechanical heart stabilizers manufactured by companies such as Medtronic Inc and Guidant Corporation, owned by Boston Scientific, is used in about 20 percent of U.S. heart bypass operations.

"I would find myself hard pressed to justify it for someone who is at moderate or somewhat-high risk. I don't think the trade-off is worth it myself," Dr. Frederick Grover of the University of Colorado Denver, who worked on the study, said in a telephone interview.

The researchers, who studied 2,203 patients, said that a year after surgery, heart-related deaths had occurred in 2.7 percent of the off-pump patients, compared with 1.3 percent of those hooked to the heart-lung machine.

And among off-pump patients whose grafts were tested after surgery, 37 percent had at least one blocked graft compared to 29 percent for those who had been hooked to the pump, they reported in the New England Journal of Medicine.

The findings are another blow to advocates of such off-pump surgery, in which a device is used to immobilize part of the beating heart so doctors can stitch new blood vessels around blocked arteries.

When off-pump surgery was pioneered, advocates speculated that avoiding use of a heart-lung machine would produce shorter hospital stays, fewer complications, less bleeding, and fewer after-surgery neurological problems.

"This study actually showed that there weren't any neurological improvements in off-pump versus on-pump surgery. The length of stay was basically the same and there was no difference in how the other organs functioned as well," said Grover.

Off-pump surgery "will probably remain a technique reserved for selected patients and skilled surgeon advocates," Dr. Eric David Peterson of Duke University Medical Center wrote in a commentary.

There will still be advocates for the off-pump procedure, he wrote, because the study looked mostly at men who tended to be younger than typical candidates for bypass surgery.

Off-pump patients may not have fared as well because their surgeon sometimes had a harder time doing as many bypass grafts as planned, the researchers said.

Getting access to some parts of the heart can be more difficult during off-pump surgery, said Grover. "The exposure isn't as good in off-pump. Hooking up to a vessel on the back side of the heart, the underside of the heart, would be the usual reason for a lower number," he said.

"There are some people that really do the off-pump operation very well and very frequently, and it's one of their major areas of expertise. I doubt it will change their practice much," Grover added.

(Editing by Maggie Fox and Mohammad Zargham)