TUESDAY, Aug. 19 (HealthDay News) -- Inexpensive ultrasound imaging may be a simple way to help determine who's at high risk for a heart attack or other cardiovascular issues, a new study says.

Researchers conducted ultrasound imaging on the carotid arteries -- the two vessels that supply blood to the head and neck -- of 1,268 patients who were asymptomatic but at high risk for cardiovascular disease. They found that nearly half the patients had carotid artery disease.

The findings are published in the September issue of the journal Radiology.

"Determining the degree of stenosis, or how much the artery has narrowed, is insufficient to predict patient risk," lead researcher Dr. Markus Reiter, of the Department of Angiography and Interventional Radiology at Medical University Vienna in Austria, said in a news release issued by the journal. "We know that the majority of cardiovascular and cerebrovascular events occur in patients whose blood vessels are less than 70 percent narrowed."

Reiter and his team used ultrasound images and computer-assisted gray scale median (GSM) measurements to determine the density of the plaque lining the carotid arteries. Plaques that appear dark on ultrasound images and have a low GSM level are thought to be associated with an increased risk for clinical complications and seem to represent unstable plaques, which are more likely to rupture or burst.

Follow-up ultrasounds done several months later showed that the conditions of the arteries in 40 percent of the patients had grown worse. Of those, 37 percent had a major cardiovascular event, such as a heart attack, stroke or coronary artery bypass, within three years of the second ultrasound.

Of the others whose ultrasounds appeared better on the follow-up, 28 percent experienced a major adverse cardiovascular event.

The authors noted their findings showed that vulnerable plaque in the carotid artery indicated not only an increased risk of stroke downstream, but also was linked to cardiovascular disease progressing elsewhere in the patient.

While more studies are needed, Reiter said serial ultrasound exams may be a noninvasive way to identify whether vulnerable plaques exist and improve the effectiveness of various therapies.

"This technique will give us additional information to use in selecting patients that need aggressive treatment," he said.

More information

The American Academy of Family Physicians has more about heart attack warning signs and risk factors  .

TUESDAY, Aug. 19 (HealthDay News) -- A study to determine whether folic acid and vitamin B supplements help the heart has been cut short, because the pills weren't doing any good and might have even caused participants harm.

"This confirms what a lot of recent studies have found -- no benefit of taking vitamin B supplements to reduce the risk of heart disease, and it raises a few red flags," said Alice H. Lichtenstein, Gershoff professor of nutrition at Tufts University, Boston.

In the new study, reported in the Aug. 20 issue of the Journal of the American Medical Association, physicians at Haukeland University Hospital in Bergen, Norway, enrolled almost 3,100 volunteers. Three-quarters of them took various doses of vitamin B and folic acid (which is chemically a B vitamin), while the others got a placebo, an inactive substance.

The study was ended early, after an average follow-up of 38 months, because "we could not detect any preventive effect of intervention with folic acid plus vitamin B12 or with vitamin B6 on mortality or major cardiovascular events," the researchers reported.

They did find a slight reduction of stroke, but also a slight increase of cancer in those taking folic acid, but neither of these results reached statistical significance. The study was ended, because another Norwegian study of folic acid and vitamin B supplementation has also hinted at an increased incidence of cancer among users.

But the real bottom line here, according to Lichtenstein, is that "there is no evidence that individuals should take B vitamins to decrease the risk of heart disease, and there may be some evidence that they shouldn't."

The trials were initiated, because observational studies did link high blood levels of a protein called homocysteine with an increased risk of cardiovascular disease. In the new study, homocysteine levels did go down by 30 percent over the course of three years in people taking folic acid and vitamin B. However, there was no related effect on the risk of cardiovascular events.

So, "the observational data was great, but the interventional studies were negative," Lichtenstein said.

Food in the United States is routinely fortified with folic acid, because it reduces the incidence of a specific class of birth defects called neural tube defects. Folic acid is a synthetic form of folate, a B vitamin found in many fruits and vegetables.

"We have been optimistic about the role of antioxidants such as vitamin B in preventing heart disease, yet many of these large trials have shown that there is no benefit," said Dr. Suzanne Steinbaum, director of women and heart disease at Lenox Hill Hospital in New York City.

It's hard to say whether the reduction in cardiovascular disease seen in some observational trials was caused by vitamin supplementation or because "people taking the supplements have good lifestyles in general," Steinbaum said.

It is also possible that the benefits of vitamin supplements show up only after many years, Steinbaum said. She does recommend a daily multivitamin pill. "But at this point, it is certainly hard to recommend extra supplements when we don't have proof of benefit," Steinbaum said. "What we can recommend is a diet with fruits and vegetables that have antioxidant vitamins in them," she said.

More information

There's more on folic acid supplementation at the U.S. Department of Health & Human Services.

FRIDAY, Aug. 15 (HealthDay News) -- Statins reduce the perils facing obese people after they have the bypass surgery that restores blood flow to an endangered heart, a study finds.

The study was done to help settle a running controversy about the ill effects of obesity in such cases, said Dr. Christina C. Wee, an associate professor of medicine at Harvard Medical School, co-director of research in the division of general medicine at Beth Israel Deaconess Hospital and lead author of a report in the Aug. 19 issue of the Journal of the American College of Cardiology.

"We know that obesity, per se, is a risk factor for developing heart disease," Wee said. "But once you develop it, is obesity more detrimental than not being overweight? There have been different studies with results going both ways."

To settle the issue, Wee and her colleagues studied the outcome of bypass surgery for 1,314 people in a controlled trial, using their body-mass index (BMI) as a measure of obesity. They found that a higher BMI was associated with a higher likelihood that arteries would become blocked again.

One arm of the trial compared progression of the condition in people given either low or high doses of a statin.

"What we found was somewhat surprising," Wee said. "With low-dose statin therapy, obesity was detrimental, with more blockage. What was unexpected was that with high doses of the statin, obesity did not have much of an effect at all."

While statins are prescribed to lower blood levels of LDL cholesterol, the effect seen in the study probably had a different cause, Wee said.

"We know that statins do more than lower cholesterol," she said. "They lower inflammation, and people who are obese have greater inflammation. There is a lot of evidence that inflammation in general is not good. Since a person who is obese has more of that going on, statins tend to protect."

The study offers a good argument for giving statins after bypass surgery, Wee said. "What we can say is that if you have heart disease, particularly if you had bypass surgery, you should be on a good dose of a statin," she said. The dosage described as "high" in the study now is regarded as standard, Wee added.

"If you are overweight or obese, you really should take your statin and be aggressive about it," she said. "You get much more benefit than for someone who is thinner."

Another paper in the same issue of the journal aimed at settling a controversy about the best way to measure the danger of obesity. A prevailing school of thought holds that measuring body-mass index is good enough. Anyone with a BMI of 30 or greater is obese.

Another theory is that not only the amount of fat, but also its distribution matters, with various ways of measuring fat in the waist area indicating more risk of cardiovascular disease and other major problems.

A team at Harvard Medical School tried both methods of obesity measurements used on the 16,332 men in the Physicians Health Study and the 32,700 women in the Women's Health Study, linking incidence of cardiovascular disease to the obesity described by the two methods.

The waist fat measurements "demonstrated the strongest association with cardiovascular disease and best model fit," the researchers reported. But they added that "cardiovascular disease risk increased linearly and significantly with higher levels of all indexes."

More information

For more on statins and cholesterol, visit the U.S. Food and Drug Administration.

MONDAY, July 7 (HealthDay News) -- High intake of the omega-3 fatty acids in oily fish and vegetable cooking oils appear to help prevent heart attacks, while the omega-6 fatty acids in vegetables and nuts help keep blood pressure low, two international research teams report.

A study in Costa Rica found that high intake of omega-3 fatty acids reduced the risk of heart attack by 59 percent, said a report published in the July 8 online issue of Circulation.

In the Costa Rican study, "we compared those subjects who had heart attacks with those who did not have heart attacks," said study author Hannia Campos, a senior lecturer in nutrition at the Harvard School of Public Health. They had participants fill out food questionnaires and also analyzed body fat samples to determine levels of alpha-linolenic acid, a major omega-3 fatty acid.

A number of other studies have shown that high intake of omega-3 fatty acids is associated with lower risk of death from cardiovascular disease. This is the first study to look at its association with heart attack risk, Campos said.

"We found that the relationship is not completely linear," she said. "It plateaued after a certain level of intake. After that, higher levels do not mean increased protection."

The protective level turned out to be surprising low -- the amount in two teaspoons of soybean oil or canola oil, half a teaspoon of flaxseed oil or six to 10 walnut halves.

That protective effect could be detected, because the people in the Costa Rican study have a low level of omega-3 fatty acids in their diet, Campos said. "Their overall intake of fish is very low, much lower than in the United States, and the fish they eat are tropical, which are not as fatty as cold-water species," she said.

The high blood pressure study, reported in the July 8 online issue of Hypertension, looked at 4,680 men and women aged 40 to 59 from China, Japan, the United States and the United Kingdom. It found a significant relationship between intake of linoleic acid, an omega-6 fatty acid found in vegetables, and lower blood pressure.

The report is the latest in a series of studies designed to describe all the factors contributing to high blood pressure, said Dr. Jeremiah Stamler, a professor of preventive medicine emeritus at Northwestern Feinberg School of Medicine.

"For diet and serum cholesterol, most of the answers came in the 1960s," Stamler said. "The data on diet and blood pressure have come much more slowly."

Previous reports have shown that higher intake of calcium, magnesium and phosphorus are associated with lower blood pressure, Stamler said. Iron from vegetables -- but not meat -- also is associated with lower blood pressure, he said. "An array of macro- and micronutrients influence blood pressure in a variety of ways," Stamler said.

The latest study indicates that raising linoleic acid intake by 9 grams a day reduces systolic blood pressure (the higher of the 120/80 reading) by about 1.4 points, and diastolic pressure by about 1 point. That small reduction can have a large effect in a big population, the researchers said, with a 2-point reduction reducing coronary heart disease by 4 percent.

"The message of this study is to eat more fruit and more vegetables, more beans, less red meat and less fats," Stamler said. "Fats should be mainly selected to be unsaturated. Vegetable oils should be used but in moderation."

More information

A guide to omega-3 and omega-6 fatty acids is offered by the Vegan Society  .