Studies

Abnormal Heart Rhythm Linked to Alzheimer's

FRIDAY, April 16 (HealthDay News) -- People with atrial fibrillation, a form of abnormal heart rhythm, are more likely than others to develop dementia, including Alzheimer's disease, a new study finds.

The presence of atrial fibrillation also predicted higher death rates in dementia patients, especially among younger patients in the group studied, meaning under the age of 70.

"This leaves us with the finding that atrial fibrillation, independent of everything else, is a risk factor [for dementia]," said Dr. Gary Kennedy, director of geriatric psychiatry at Montefiore Medical Center in New York City. "This is adding one more brick in the road toward understanding that cardiovascular disease is a major risk factor for dementia."

"Alzheimer's disease, in particular, is one where we don't quite understand the risk factors and what causes it, so studies [like this] that try to investigate the causative effect will help us understand that and ultimately design therapies and approaches to prevent or minimize disease," added Dr. Jared Bunch, lead author of a study appearing in the April edition of the HeartRhythm Journal and a cardiologist/ electrophysiologist with Intermountain Medical Center in Murray, Utah.

This study, however, was not specifically set up to establish a direct cause-and-effect relationship.

The authors looked at 37,025 patients without atrial fibrillation or dementia, aged 60 to 90, over a five-year period.

Individuals who developed atrial fibrillation had a higher risk of all types of dementia, even when other risk factors were taken into account. Alzheimer's disease is by far the most common form of dementia.

More surprising was that those in the younger group -- under age 70 -- who had atrial fibrillation had the highest risk of developing dementia, even though dementia is normally associated with aging. People in this group were also at a 38 percent higher risk of dying.

Among the 764 patients who developed both conditions, diagnosis of atrial fibrillation usually happened first, followed by a diagnosis of dementia. Sometimes the diagnoses occurred simultaneously, the researchers noted.

The authors hypothesized that both atrial fibrillation and dementia may arise from the same risk factors, such as hypertension. Another possibility is that atrial fibrillation increases inflammation, and dementia has been shown to be higher in people with signs of systemic inflammation. Investigating whether treatment of hypertension and/or inflammation in AF patients might help curb the risk of dementia is an area of future study, the researchers added.

"From a public health perspective, the best thing we can do to decrease the coming epidemic of Alzheimer's disease is to do a much better, more aggressive job of helping people with heart disease," Kennedy said. "That means diet and exercise, of course -- everyone knows that. We need to look at obstacles that people encounter beyond their own behavior, obstacles we put up environmentally in the workplace, in the school, that keep people from having better diet and exercise. A heart-healthy diet and lifestyle are really the best means we have available to prevent dementia."

About 2.2 million Americans have atrial fibrillation, while an estimated 5.5 million suffer from Alzheimer's.

More information

The American Heart Association has more on atrial fibrillation.

SOURCES: Jared Bunch, M.D., cardiologist and electrophysiologist, Intermountain Medical Center, Murray, Utah; Gary Kennedy, M.D., director, geriatric psychiatry, Montefiore Medical Center, New York City; April 2010 Heart Rhythm Journal

Adult Stem Cells Can Repair Damaged Heart

FRIDAY, Dec. 4 (HealthDay News) -- Adult stem cells appear to help repair heart attack damage, a new study shows.

The phase 1 study of 53 patients found that stem cells from donor bone marrow promoted the growth of new blood vessels in heart tissue damaged by heart attack.

The patients received the stem cell injections within 10 days of having a heart attack. During follow-up, they were compared to patients who had received a placebo injection.

After six months, those who got the stem cells were four times more likely to be better off overall, pumped more blood with each heartbeat, and had one-quarter as many irregular heartbeats, when compared to the placebo group. There also were no serious side effects with the stem cell treatment, according to the report published in the Dec. 8 issue of the Journal of the American College of Cardiology.

This is the strongest evidence so far that adult stem cells can repair heart attack damage, the Rush University Medical Center researchers said. It had been believed that only embryonic stem cells could turn into heart or other organ cells.

"The results point to a promising new treatment for heart attack patients that could reduce [death] and lessen the need for heart transplants," Dr. Gary Schaer, head of the Rush Cardiac Catheterization Laboratory, said in a news release from the university.

More information

The U.S. National Heart, Lung, and Blood Institute has more about heart attack.

SOURCE: Rush University Medical Center, news release, Dec. 2, 2009

A Little Chocolate May Do the Heart Good

TUESDAY, March 30 (HealthDay News) -- For those who believe in the Easter bunny (or at least in what he is believed to bring), good news awaits.

Just one small square of chocolate a day might help lower your blood pressure and reduce your risk for heart disease.

After analyzing the diet and health habits of 19,357 people, aged 35 to 65, for at least 10 years, German researchers found that those who ate the most chocolate (an average of 7.5 grams, or 0.3 ounces, a day) had lower blood pressure and were 39 percent less likely to have a heart attack than those who ate the least amount of chocolate (an average of 1.7 grams, or 0.06 ounces, a day).

"To put that in terms of absolute risk, if people in the group eating the least amount of chocolate [of whom 219 per 10,000 had a heart attack or stroke] increased their chocolate intake by 6 grams [0.2 ounces] a day, 85 fewer heart attacks and strokes per 10,000 people could be expected to occur over a period of about 10 years," study leader Dr. Brian Buijsse, a nutritional epidemiologist at the German Institute of Human Nutrition, said in a news release from the European Heart Journal, which published the findings online Tuesday.

"If the 39 percent lower risk is generalized to the general population, the number of avoidable heart attacks and strokes could be higher because the absolute risk in the general population is higher," he said.

Six grams of chocolate is equivalent to about one small square of a 100 gram (3.5 ounce) bar, the researchers said.

But Buijsse cautioned that eating chocolate shouldn't increase a person's overall intake of calories or reduce the consumption of healthy foods.

"Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense foods, such as snacks, in order to keep body weight stable," he said.

More information

The American Heart Association has more about preventing heart disease, heart attack and stroke.

SOURCE: European Heart Journal, news release, March 30, 2010