Older people are vulnerable to infection and inflammation during heart bypass surgery and this may trigger cognitive decline.

It's already known that cognitive decline - memory loss and difficulties in problem solving - may follow a heart bypass operation. One factor seems to be inflammation caused by release of toxins by gut bacteria while the patient is on the heart-lung machine. Normally the immune system can deal with these toxins, but in older people, immunity may be impaired.

Doctors at Duke University have measured the level of antibodies to these toxins in a group of 460 patients undergoing bypass surgery. The higher the antibody level, the stronger the immune system. The patients were aged between 23 and 87 and they also had a battery of cognitive tests before and six weeks after surgery. This showed that 36 per cent experienced significant cognitive decline.

For older people, lower levels of antibody were a factor linked to cognitive decline, the researchers say. The younger individuals had a stronger immune response. Maybe cognitive decline following bypass surgery could be avoided by boosting weakened immunity beforehand.

Source

Stroke February 2003