In a new review, researchers looked over previous studies conducted on open heart surgery patients to determine whether these individuals tend to experience a difference in cognition after the procedure. Specifically, they looked into two types of heart valve surgeries, mitral and aortic, to see if each was associated with better or worse cognitive outcomes.

Their findings are published in the Journal of the American Geriatrics Society.

Most people who need aortic valve surgery are over the age of 65, and the number of older adults with aortic stenosis is expected to double by 2050. Understanding how heart valve surgery may affect an older adult’s cognition is very important.

For the study, researchers reviewed 12 previous studies that included hundreds of people who had received heart valve surgery. In each of the studies, participants had been tested before and after surgery to determine their ability to remember, think, and make decisions.

The findings reveal that within the first month after valve surgery, patients in the studies experienced some cognitive decline compared to their pre-surgery state.

Up to six months after surgery, however, patients’ cognitive health had mostly returned to normal. One-third of the studies included in this review even showed small improvements in cognition half a year after surgery.

The most common condition to require valve surgery is aortic stenosis. The aorta is the heart valve that controls blood flow from the heart to the rest of the body. Aortic stenosis happens when the aortic valve doesn’t allow blood to flow out of the heart properly.

The researchers found that aortic valve surgery was associated with more early cognitive problems than mitral valve surgery.

Patients who had undergone mitral valve surgery experienced a mild decline from their one-month check-up to their check-ups from two to six months after surgery. But those who had received aortic valve surgery experienced poorer cognitive function the month after surgery, although they tended to improve after that.

Importantly, however, aortic valve patients were, on average, a decade older than mitral valve patients (68 years vs. 57). As such, the increased age of aortic valve surgery patients might have affected their greater cognitive decline.

The researchers concluded that heart valve surgery patients are at risk of cognitive problems up to six months after surgery. Patients undergoing aortic valve surgery — the majority of whom are older adults — are at greater risk of early cognitive decline within the first month after surgery than those having mitral valve surgery. However, cognitive health in both groups appears largely to return to what it was before surgery within the six months after surgery.

Source: American Geriatrics Society