WEDNESDAY, Feb. 1, 2012 (MedPage Today) — People with heart failure lose gray matter in regions of the brain that are important for cognitive function, researchers reported.
They also have worse immediate and long-term memory and psychomotor speed, according to Osvaldo Almeida, MD, PhD, of the University of Western Australia in Perth, Australia, and colleagues.
One clinical implication: heart failure patients may find it difficult to follow complicated self-care advice, Almeida and colleagues reported online in the European Heart Journal.
The physiological pathways that link heart failure with loss of brain tissue and impaired memory remain unclear, the researchers wrote, and need more study. It's also not clear if the observed changes worsen over time, they said.
Heart failure is a common consequence of heart disease and has been shown to be associated with impairment of general mental ability, memory, and attention, the researchers noted.
But it has not been clear if those deficits are a result of the heart failure itself or comorbid conditions, such as ischemic heart disease or cerebrovascular disease.
To try to clear up the picture, Almeida and colleagues conducted a cross-sectional analysis of 155 volunteers, including 35 with systolic heart failure, 56 with a history of ischemic heart disease but not heart failure, and 64 healthy controls.
Participants were at least 45 years old and did not have overt cognitive impairment. All but 11 of the heart failure patients showed signs that ischemic heart disease had caused the systolic heart failure.
The researchers measured overall cognitive performance — the primary outcome of the study — using the Cambridge Cognitive Examination of the Elderly Revised. They also measured such things as memory, psychomotor speed, and attention.
They used magnetic resonance imaging to compare gray matter volumes among participants.
The researchers found that participants with heart failure did not have a significantly worse performance than either healthy controls or those with ischemic heart disease on the main cognitive measure.
On the other hand, the heart failure patients had significantly lower scores than healthy controls on measures of immediate recall, long delay recall, and digit code.
Those with a history of ischemia also had significantly lower long delay recall scores than healthy controls. And those with ischemia had a similar but less extensive pattern of gray matter loss compared with healthy controls.
There were no regions of the brain in which participants with heart failure had more gray matter than those in the other groups. Similarly, there were no regions in which those with a history of ischemia had more gray matter than the healthy controls.
Both ischemic heart disease and heart failure "are associated with a loss of cells in certain brain regions that are important for the modulation of emotions and mental activity," Almeida said in a statement — a loss that is more pronounced in heart failure patients.
He and his colleagues cautioned that the study might have had a "healthy participant bias" that would tend to minimize differences, so that the findings may be an underestimate.
The study also included only patients with systolic heart failure, so it isn't clear if the results apply to those with nonsystolic dysfunction.
And because the study was a snapshot, it's not possible to draw conclusions about causal factors, they added.
Last Updated: 2/1/2012