Mark Newman

Updated:Mar 21,2011

Mark Newman, M.D.

Mark NewmanInstitution: Duke University

Bypass Surgery Leads to Decline in Cognitive Function
A study led by Mark Newman, M.D., an anesthesiologist at Duke University, has found that for many people bypass surgery results in trouble with memory, concentration and other thought processes. 

Researchers administered mental exams to 251 patients before surgery, before their discharge from the hospital and then at intervals over the next five years. They found that about half the patients showed a decline just before their release, although a number of them improved over the next few weeks. About a third still showed declines at six weeks after surgery, and about a quarter at six months.

The crucial finding is that about 42 percent of patients performed worse on the test five years after surgery than they did before the procedure. Most of these patients were among those who showed declines just after surgery. Dr. Newman said this pattern indicates that some of the early damage results in long-term dysfunction.

Dr. Newman advised that people should not use the results of this study as a deterrent to having bypass surgery. "People who avoid the operation might be limiting what could be a substantial improvement in their quality of life," he said. Bypass surgery is typically performed to relieve chest pain and to prevent heart attacks caused by blocked coronary arteries.

Between 500,000 and 600,000 bypass surgeries are performed annually in the United States. The study was funded by an American Heart Association National Center Grant-in-Aid.