Heart failure linked to cognitive decline

1 February 2012

MedWire News: Heart failure (HF) is associated with a decline in mental processes and a loss of gray matter (GM) in the brain, Australian researchers have found.

These changes can make it difficult for HF patients to remember and carry out instructions such as taking the right medications at the correct times, report Osvaldo Almeida (University of Western Australia, Crawley, Perth) and colleagues in the European Heart Journal.

They conducted a cross-sectional study of 35 participants with an established diagnosis of HF, left ventricular dysfunction (ejection fraction [EF]<0.4), and clinical symptoms consistent with a diagnosis of HF for at least 6 months. The study also included 56 patients with ischemic heart disease (IHD), as well as 64 controls without either HF or IHD.

Control patients with IHD had documented clinical and biochemical evidence of past myocardial infarction, normal left ventricular function (EF>0.6), and no clinical symptoms. Control patients without IHD had no reported symptoms or history suggestive of angina, myocardial infarction, and HF, and had normal left ventricular function (healthy controls).

The Cambridge Cognitive Examination of the Elderly Revised (CAMCOG) was the primary outcome measure of the study. The CAMCOG is a neuropsychologic battery that assesses various aspects of cognitive functioning, including orientation, language, memory, attention and concentration, praxis, perception, calculation, and executive functions. The assessment produces a total score that ranges from 0 to 105, where a higher score indicates better performance.

The CAMCOG scores of participants with IHD and HF were 1.8 and 2.8 points lower, respectively, than healthy controls. However, only the reduction in CAMCOG score for HF patients was significant (p=0.029).

Patients with HF also had significantly lower scores than healthy controls in measures of immediate recall (6.9 points lower), long delay recall (–1.5 points), and digit code (–7 points) according to the California Verbal Learning Test.

Those in the IHD group also had lower long delay recall scores than controls without IHD (–1.3 points).

Using magnetic resonance imaging (MRI) scanning, the team found that compared with healthy controls, the brain regions of HF participants that showed the greatest loss of GM were the left cingulate, right inferior frontal gyrus, left middle and superior frontal gyri, right middle temporal lobe, right and left anterior cingulate, right middle frontal gyrus, inferior and precentral frontal gyri, right caudate, and occipital-parietal regions.

When the researchers compared participants with HF and IHD, a similar, less-extensive pattern was found, “which suggests that these changes may be relatively specific to HF,” they say.

They note that the regions of the brain that showed loss of GM are believed to be vital for memory, reasoning, and planning. “Consequently, loss of brain cells in these regions may affect a person’s performance in a number of different areas such as memory, behavior modification, inhibition, both emotional and cognitive, and organization,” Almeida added in a press statement.

“Primary and secondary prevention are essential to minimize the impact of heart disease on brain structure and function,” he said.

“Patients with HF may have trouble following complex management strategies, and, therefore, treatment messages should be simply and clear. Health professionals and patients need to be aware that problems caused by heart disease are not limited to the heart.”

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Eur Heart J 2012; Advance online publication