SAN FRANCISCO — A crucial part of bypass surgery — stopping the heart and putting the patient on a heart-lung machine — is safe even in the elderly and doesn’t cause mental decline as many people have feared, two studies show.
Bypass surgery is one of the most common operations in the world. There is great debate about the best way to do it, and patients often are given a choice.
Usually doctors stop the heart to make it easier to connect new blood vessels and make detours around blocked ones. But some patients later complain of ‘‘pump head’’ — mental decline thought to be from the heart-lung machines used to pump their blood while their hearts could not. So surgeons started doing ‘‘off-pump’’ bypasses on beating hearts. Nearly one quarter of bypasses are done this way now. But that brought a new complaint: Results on the blood vessels seemed not as good.
The new studies were aimed at testing all these factors in a rigorous way to see which method was best. The studies were discussed Monday at an American College of Cardiology conference in San Francisco and published online by the New England Journal of Medicine.
Dr. Andre Lamy of Canada’s McMaster University in Hamilton, Ontario, led a study of 4,752 people in 19 countries. They were randomly assigned to have bypasses with or without the use of heart pumps.
After one year, there were no big differences in the rates of death, heart attack, stroke or kidney failure in the two groups. Slightly more people who had bypasses without a heart-lung machine needed a follow-up procedure to open clogged arteries but the difference was so small it could have occurred by chance.