TUESDAY, Feb. 2 (HealthDay News) --When a doctor wants to assess the condition of heart arteries without putting a gadget into those blood vessels, the X-ray technology called computed tomography -- more commonly called a CT scan -- is better than magnetic resonance imaging, or MRI, a German review of studies has found.

"For ruling out coronary artery disease, CT is more accurate than MRI," researchers from Humboldt University in Berlin said in a report in the Feb. 2 issue of the Annals of Internal Medicine.

The standard method for checking heart arteries is coronary angiography, which involves threading a thin, flexible tube, called a catheter, into the heart. But doctors do not always want to run the risks that can be associated with that technique, and the leading candidates for less invasive assessment are CT and MRI.

CT is a scanning technique using X-rays that produce a set of slice-by-slice heart images, up to 16 slices, depending on the power of the machine. MRI uses a powerful magnetic field and pulses of radiowave energy to create images.

The German researchers looked at results of 109 published studies of noninvasive heart artery imaging, including 89 that used CT and 20 that used MRI and involving 8,505 people. In the studies of people with suspected coronary artery disease, CT proved to be 97 percent sensitive, compared with 87 percent sensitivity for MRI exams, the analysis found. Sensitivity rates the ability of a test to correctly identify people who have a particular disease.

"This article holds no surprises whatever," said Dr. Uwe Joseph Schoepf, a professor of radiology and cardiology at the Medical University of South Carolina. "This is really something that is sort of common trade knowledge."

Indeed, CT and MRI are not contenders in clinical practice but are used for different reasons to make different assessments, Schoepf said. "It is a question of what specific question you are looking to answer," he said.

CT is the preferred noninvasive technology for assessing the condition of heart arteries, whether there is narrowing that might end with the total blockage that causes a heart attack, Schoepf said. "MRI is not in current use to look at coronary artery disease," he said. "We use MRI angiography if we are interested in heart muscle, as when there are congenital heart abnormalities in children. The strength of MRI is that it shows tissue configuration."

That difference helps explain why there are so few studies doing head-to-head comparison of CT versus MRI, he said. The German analysis found only five such studies.

Dr. Ricardo Cury, director of cardiac MRI and CT at Baptist Cardiac & Vascular Institute in Miami and a consultant radiologist at Massachusetts General Hospital, said that the "meta-analysis demonstrates a knowledge that we have accumulated for the past several years."

"For imaging of the cardiac arteries, CT is more robust," Cury said. "We perform MRI on a clinical basis more for functional assessment, as opposed to looking at the coronary arteries."

Though that difference is well established among radiologists, the new study may be of assistance in the general medical community, including general cardiologists, because "it summarizes the advantages of CT at this point in time," he said.

Indeed, CT appears to be better for assessment of coronary artery disease, matched against not only MRI but other methods, such as echocardiography, he said.

More information

The Cleveland Clinic has more on CT, MRI and similar tests  .

MONDAY, Feb. 1 (HealthDay News) -- Problems with memory or thinking abilities could signal an increased likelihood for a stroke in the future.

Swedish researchers found that older men who were not diagnosed as having dementia but who did poorly on a test of mental function had a greatly increased risk for stroke.

It's not yet clear whether the test can be used routinely to improve predictions based on established risk factors, said Dr. Bernice Wiberg, a doctoral fellow in geriatrics and internal medicine at Uppsala University and lead author of a report on the research, published Feb. 2 in Neurology.

"We have to be very careful in saying that it compares to high blood pressure, diabetes and other risk factors," Wiberg said.

But there are indications that the test results could show the chances of survival for someone who has a stroke, she said.

The research involved 930 Swedish men, who averaged 70 years old at the start of the study. None had a history of stroke. They were given three widely used tests of mental function: Trail Making Test A, which measures attention and visual-motor abilities; Trail Making Test B, which measures the ability to execute and model a plan; and the Mini Mental State Examination, used to measure cognitive decline.

In Trail Making Test A, participants draw lines to connect circles numbered 1 through 25. In the B test, the circles include both numbers and letters, and lines are drawn to alternate between those numbers and letters (1-A-2-B-3-C, etc.).

In the next 13 years, 166 of the men had a stroke or transient ischemic attack (TIA), a brief interruption of blood flow to the brain. The 25 percent of men who performed worst on the B test were three times more likely to have a stroke or a TIA than the 25 percent of the men with the highest scores, the study found.

"Our results support the idea that cognitive decline, regardless of whether a person has dementia, may predict risk of stroke," Wiberg said.

The Trail Making Test B is easy to do, she said: "You just need a sheet of paper and a pen." However, the study was not designed to determine whether the test results added predictive value to the usual measures of stroke risk. "That is something we didn't actually measure," Wiberg said.

Whether the test could be used to identify people needing more intensive stroke prevention measures requires more research, she added.

The Trail Making Test B is sensitive to frontal lobe injuries of the brain, the region involved in executive function, explained Dr. Larry B. Goldstein, director of the Duke University Stroke Center.

"They might be identifying a subgroup of the population that has had some degree of injury,' Goldstein said. "A sizeable proportion of those injures goes undetected. So they are presumably detecting patients who have major risk factors and should be treated aggressively with preventive measures."

The researchers are continuing to follow the men who had a stroke or TIA, so far for an average of 3.5 years, indicating a grim predictive value -- if the worst should occur -- for test B.

Wiberg said that "very preliminary results," which have not yet been published, show that "if you have a bad test result, when you have a stroke you do have a worse outcome."

"If you have a bad test result at 70 years and if you do get a stroke, you have a lessened chance to survive for a long time," she said.

The Swedish study adds to the list of unconventional factors linked to the risk for stroke.

One recent study of more than 13,000 Americans found an association with obesity, measured by either body-mass index or waist circumference. In some cases, the most obese individuals were more than three times as likely to have a stroke as the leanest.

More information

The American Heart Association has more on the risk factors for stroke  .

MONDAY, Feb. 1 (HealthDay News) -- The growing number of Americans who are taking traditional herbal medications for heart problems are unaware of the dangers those treatments pose, a new report says.

"They may be safe," said Dr. Arshad Jahangir, a consultant cardiologist at the Mayo Clinic in Arizona, and author of a report in the Feb. 9 issue of the Journal of the American College of Cardiology. "But in the United States, where patients often take multiple medications, there is a potential for harm."

While up-to-date statistics aren't available, it appears that more than 15 million Americans are using herbal remedies and the number is growing, Jahangir said.

"Consumers of these products think they are not getting proper attention from their physicians," he said. "The typical hands-on communication between physician and patient is getting compromised, and they are seeking that type of relationship."

Popular herbal remedies such as St. John's wort "have been used traditionally in populations where there are no other medications to use," Jahangir said. But now multiple medications are common for older people, so "anyone taking herbal products needs to pay attention to the advice of their medical providers, and they often don't ask for that advice," he said.

Herbal medications can affect the activity of prescription drugs, dampening or enhancing their effects, Jahangir said. For example, St. John's wort, which is used for a number of conditions, including depression and sleep disturbances, has its major effect on the liver, which is involved in the metabolism of many drugs, especially those for heart disease, he said.

"If you take it on top of these medications, their activity will be reduced -- blood pressure medications, rhythm-controlling medications," Jahangir said. "Most important, it can have an effect for transplant patients, since it is immunosuppressive."

Other herbs can also be problematic.

Ginkgo biloba, which is supposed to sharpen the mind, increases bleeding risk in those taking the blood-thinner warfarin or aspirin, while garlic, which is believed to boost the immune system, can increase the chances of bleeding among those taking warfarin, the researchers noted.

Even grapefruit juice, recommended as an aid in weight-loss programs, has potential dangers, he noted. It interferes with enzymes that break down drugs in the digestive system, including the statins used to lower cholesterol levels and amiodarone (Cordarone), used to treat and prevent abnormal heart rhythms, Jahangir said.

"Anyone taking alternative medical and herbal products needs to bring it to the attention of their medical providers," Jahangir said. "Often they don't, and physicians don't actively seek that information."

There is no formal count of Americans taking such medications, said Dr. Wallace Sampson, clinical professor emeritus of medicine at Stanford University, and founder and editor emeritus of the Scientific Review of Alternative Medicine, a decided skeptic on the issue. The most-cited data come from a survey whose results were published in 1993. The best current estimate is that up to 30 percent of the U.S. population turn to herbal remedies and similar unapproved medications, Sampson noted.

There are periodic reports about the potential dangers of such remedies, Sampson added. "There are quite a number of them in the medical literature, targeted to different specialties," he said. "Cardiac ones are quite high on the list, also drugs that affect the immune system."

Most controlled studies of alternative medications have not shown benefit, "but when you do enough studies you get a few positive results and that keeps the field alive," Sampson said.

Negative results haven't killed the hope that herbal medications can help, he said: "It's a free country, and all you can do is educate and hope people learn."

More information

Learn about complementary and alternative medicine from New York Online Access to Health  .

MONDAY, Jan. 25 (HealthDay News) -- Researchers report that people with chest pain who are given an electrocardiogram by paramedics before reaching the hospital don't wait as long to receive treatment to open their arteries.

They often were able to bypass the emergency room and go directly to the cardiac catheterization laboratory for treatment with what's commonly known as an angioplasty, the study found.

They were treated 60 minutes, on average, after reaching the hospital, compared with 91 minutes for people who did not have an EKG before arriving at the hospital. The findings were published in the January issue of Catheterization and Cardiovascular Interventions.

Research has shown that rapid angioplasty treatment reduces the chances of dying within the next year.

For the study, the researchers examined medical records for cardiac patients taken to three hospitals in Southeast Michigan from 2003 to 2008. When EKGs were done outside of a hospital, data were transmitted to the hospital before patients arrived so doctors could prepare.

Of those who did not have an EKG done before arrival, 2 percent (seven of 241 patients) died in the hospital. None of the 108 patients who were given pre-arrival EKGs died in the hospital, the study reported.

More information

The U.S. National Heart, Lung, and Blood Institute has more on EKGs.