Saturday, December 30, 2006

No Link Between Coronary Bypass Surgery and Dementia

Fears about a link between coronary artery bypass surgery and dementia are unwarranted, according to Mayo Clinic researchers.

A possible link between bypass surgery and development of long-term cognitive decline has been a controversial medical issue.

In a study of residents of Rochester, Minn., bypass surgery was not a risk factor for dementia, according to lead researcher David Knopman, M.D., a Mayo Clinic neurologist.

According to Knopman, the study approached the issue in a unique way, noting that past studies have focused on those who have had the surgery without a suitable comparison group.

The Mayo Clinic study started with dementia patients and worked backward to find out whether these patients were more likely to have previously undergone bypass surgery. The researchers compared the dementia patients who had undergone bypass surgery to a non-demented control group.

In the five-year period studied, there were 564 dementia cases. Of these, 21 had undergone bypass surgery before developing dementia. In the control group, 23 people had undergone bypass surgery.

Knopman said his patients often raise the issue of a dementia-bypass surgery connection, noting that some claim to have begun experiencing memory problems after their surgery even though they didn’t have any obvious surgical complications. He said the study findings would allow him to tell concerned patients that their bypass surgery did not directly cause their memory issues. He acknowledged that the study does not discount the existence of short-term cognitive issues post-bypass surgery.