Almost half of all patients with heart failure have problems with memory and other aspects of cognitive functioning, a new US study has indicated.

Memory problems and other cognitive deficits may be an important factor to consider in planning medical care for patients with heart failure, researchers from the University of California said.

The researchers tested 50 people with heart failure and 50 people without heart failure for cognitive (intellectual) function. The participants were matched for age and estimated intelligence. Overall, patients with heart failure scored lower than healthy patients in 14 out of 19 cognitive tests. Forty-six of the heart failure patients were rated as having mild to severe cognitive impairment, compared to a 16% rate of mild impairment in healthy patients.

According to the researchers, memory problems, especially short-term memory, were the most common type of cognitive impairment. 

With adjustment for other factors, the risk of cognitive impairment was more than four times higher in the heart failure group. The rate, types, and severity of cognitive impairment in this group of patients living with heart failure (most of whom had mild to moderate heart failure) were similar to those seen in patients with end-stage heart failure.

Changes in cognitive function have long been recognized in patients with heart disease. Although past reports have noticed an increased rate of cognitive impairment among people with heart failure, this has been assumed to reflect the age-related risk of memory decline.

These findings may have important implications for the care of patients with heart failure, the researchers believe.

“Care instructions and medication or dietary changes need to be written and given verbally because of patient difficulties with information requiring attention, learning, and memory functions,” they said.

“This is a very important article dealing with a neglected area of research,” said Dr Barry M. Massie, Editor-in-Chief of the Journal of Cardiac Failure. “It was closely related to the severity of symptoms or left ventricular dysfunction. Clinicians should be aware of this problem, as it has the potential to interfere with optimal patient management,” he said.

The results of the study were published in the Journal of Cardiac Failure.