Heart And Brain Health Linked

February 2009 - Almost one half of patients with heart failure have memory failure and other problems in cognitive functioning, according to a study in the February issue of the Journal of Cardiac Failure (https://www.elsevier.com/locate/cardfail). Such problems may be important issues to consider when planning medical care for patients with heart failure.

The research, led by Mary Jane Sauvé, D.N.Sc., R.N., of the University of California, Davis, tested cognitive function in 50 patients with mostly mild to moderate heart failure and a control group of 50 subjects without heart failure. They were matched for age and estimated intelligence. Overall, the patients with heart failure registered lower scores than the control subjects on 14 out of 19 cognitive tests. The researchers rated 46% of the heart failure group as having mild to severe cognitive impairment. This compared to a 16% rating of mild impairment in the control subjects. Short-term memory problems were the most common cognitive deficits.

Adjusting for other factors, the subjects with heart failure had four times the risk of cognitive impairment than the control group. The heart failure group presented similar rates, types, and severity of cognitive impairment to those seen in patients with end-stage heart failure waiting for heart transplantation.

Dr. Sauvé and her colleagues believe that these findings could have important implications for the care of patients with heart failure, for example:

"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."

Barry M. Massie, M.D., Editor-in-Chief of the Journal of Cardiac Failure said:

"This is a very important article dealing with a neglected area of research. The authors have performed a well-designed study assessing heart failure patients for cognitive impairment, which was significant in a substantial proportion of patients. Furthermore, 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."

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January 2008 - Two recent studies have thrown new light on links between cardiovascular and brain health.

Research led by the Johns Hopkins University School of Medicine published in Neurology showed that Alzheimer's disease (AD) may progress more rapidly in people with hypertension (high blood pressure) or atrial fibrillation (irregular heartbeat). The study concluded that treating these conditions may slow memory loss in patients able to tolerate current medication.

Lead researcher Michelle M. Mielke of the department of psychiatry and behavioral sciences said:

"The possibility that specific vascular conditions may affect how fast a person with AD declines provides new opportunities for slowing the rate of AD progression. Treatments for atrial fibrillation and high blood pressure are relatively inexpensive and safe and may reduce memory decline in AD patients with these conditions."

The study examined 135 men and women newly diagnosed with AD enrolled in the Cache County (Utah) Study on Memory Health and Aging, which has been monitoring 5092 people 65 or older since 1995. All had undergone annual memory tests for an average of three years.

Researchers found that ten participants with high blood pressure (systolic pressure over 160) when diagnosed with AD showed a rate of memory loss approximately 100 per cent faster than those with normal blood pressure. Ten with atrial fibrillation at the time of diagnosis showed a 75 per cent faster rate of memory decline than those without.

Michelle Mielke explained:

"What makes this group and study unique is that we have been following these participants in the community for over a decade, even before they were first diagnosed with AD, so we know a good deal about their medical history. Studies that enrol AD patients only from clinics may miss key factors, such as date of onset and history of cardiovascular disease and treatment."

Similar studies are in progress using larger sample sizes to increase understanding of the potential role played by vascular factors before AD diagnosis and during disease progression. Research led by Johns Hopkins psychiatrist Paul Rosenberg examining the effects of high blood pressure and high cholesterol treatments such as beta-blockers, diuretics, calcium-channel blockers and statins on cognitive and functional decline is due for publication.

In a separate study from the University of Pittsburgh presented at the annual meeting of the Radiological Society of North America researchers found reduced blood flow in the brains of adults with Alzheimer's disease and hypertension.

Co-author Cyrus Raji said:

"While hypertension is not a cause of Alzheimer's disease, our study shows that it is another hit on the brain that increases its vulnerability to the effects of the disease."

Researchers explain that according to the National Heart, Lung and Blood Institute, approximately 50 million Americans have hypertension and are at increased risk of heart attack, stroke and aneurysm. There is increasing evidence linking cardiovascular health to brain health.

Researchers used the non-invasive technique of arterial spin-labeled magnetic resonance imaging (MRI) to measure blood flow in the brain in a group of older adults including 48 normal individuals (of whom 38 had hypertension), 20 Alzheimer's patients (50 per cent with hypertension) and 20 with mild cognitive impairment (50 per cent with hypertension). Researchers explain that mild cognitive impairment (affecting brain functions such as language, attention and reasoning) is a transition stage between normal aging deficits and greater levels of dementia.

The study found that blood flow in the brain was substantially decreased in all patients with hypertension compared to those without. Cerebral blood flow was lowest among Alzheimer's patients, but was also significantly lower in those with hypertension in the normal group.

Co-author Oscar Lopez, professor of neurology and psychiatry added:

"This study demonstrates that good vascular health is also good for the brain. Even in people with Alzheimer's disease, it is important to detect and aggressively treat hypertension and also to focus on disease prevention."

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