WEDNESDAY, July 2 (HealthDay News) -- Injecting the artery-constricting hormone vasopressin in addition to adrenaline did not improve survival among people who had sudden cardiac arrest in an European trial, but American cardiologists said the finding does not rule out use of that treatment in some cases.

The report comes from a group, primarily French, that several years ago described promising results of combining vasopressin and epinephrine -- the formal name of adrenaline -- as part of the emergency treatment of cardiac arrest. The American Heart Association responded to that report in guidelines saying that a first shot of vasopressin might be substituted for adrenaline, the traditional drug for cardiac arrest, in some cases.

But the latest report, on a total of nearly 3,000 people, found that "the combination of vasopressin and epinephrine during advanced cardiac life support for out-of-hospital cardiac arrest does not improve outcome." The study was published in the July 3 issue of the New England Journal of Medicine.

In each group, about one in five of those treated survived long enough to be admitted to a hospital -- 20.7 percent of the combined therapy group, 21.3 percent of the adrenaline-only group. The one-year survival rate was 1.3 percent for those given the two drugs, 2.1 percent of those given only adrenaline.

The reason for not giving up entirely on vasopressin is due to the average response time in the French study, said Dr. Joseph P. Ornato, chairman of emergency medicine at Virginia Commonwealth University, and a member of the committee that drew up the heart association guidelines.

"Paris is a city with a lot of traffic," Ornato said. "If you look at the time of collapse to the time of treatment, the first crew was at the scene in an average of 7.2 minutes. They didn't start to treat until 16.3 minutes. The first steady drug injection was not until 21 minutes."

That interval means everything, because "we lose roughly 10 percent of the odds of the resuscitation every minute," Ornato said.

In Richmond, "90 percent of the time, we respond within eight minutes or less," he said.

And so, Ornato said, "I am less than convinced that this completely answers the question, because I don't know what it means when your drugs don't start until 20 minutes after the heart has stopped."

The trial "raises as many questions as it answers," said Dr. Nisha Chandra-Strobos, chief of cardiology at the Bayview division of Johns Hopkins University.

The slow response time is one major reason, she said: "A time to injection of 21 minutes, the game is really over at that time."

The heart association guidelines which Ornato helped prepare apply only to the medical personnel called for emergency treatment of cardiac arrest. The heart association advises persons without medical training to call for that help as quickly as possible by dialing 911.

Emergency measures can be taken before medical help arrives. Newly updated advice by the heart association says that simply depressing the chest periodically and continually can contribute to survival. If the cardiac arrest occurs in a public place such as an airport, a portable defibrillator may be available. It should be placed against the chest to deliver an electric shock that might start the heart beating again.

More information

The symptoms of cardiac arrest and what to do about them are described by the American Heart Association  .

THURSDAY, June 26 (HealthDay News) -- If you're an older American with no major health problems, chances are about one in 10 that you've had a stroke and didn't know it.

It was probably not severe enough to cause recognizable symptoms, such as vision problems, facial weakness or trouble walking, but it was still a blockage of a brain artery, and it reduced your thinking powers just a bit.

That estimate comes from a new study of 2,040 people, average age 62, in the long-running Framingham Offspring Study. MRI scans showed that 10.7 percent of them had experienced what study author Dr. Sudha Seshadri, an associate professor of neurology at Boston University, called "a silent brain infarct."

It's the cerebral equivalent of what physicians call a myocardial infarct -- blockage of a blood vessel that causes damage to tissue. In the case of a silent stroke, the blockage and the damage occurs in the brain, without symptoms.

A silent stroke is different from a transient ischemic attack (TIA), a momentary loss of brain function, Seshadri said. A TIA causes some symptoms, while a silent stroke, by definition, doesn't. But both are warning signs to pay attention to the well-known risk factors for stroke, such as cholesterol levels, blood pressure, obesity and smoking, she said.

The incidence found in the Framingham Offspring study "was within the ballpark of what prior studies have suggested," Seshadri said. "But this was a group of people who were younger than in most of the prior studies. The fact that one in 10 persons had silent attacks that had subtle side effects on the brain is something we should be concerned about and should address."

The report was published in the online issue of Stroke.

The effects of a silent brain infarct show up on an MRI scan as "small lesions in various parts of the brain," Seshadri said. "We can't tell from that whether they had a symptomatic attack." And the MRI scans give no clues as to when the silent stroke occurred.

Testing showed that "on average, compared to age-matched controls, those with lesions do have subtle signs, such as loss of flexibility of talk," she said.

The incidence seen in the study did not startle Dr. Claudette Brooks, director of the neurovascular laboratory at West Virginia University Health Sciences Center.

"When I look for the cause of headaches and similar problems, it doesn't surprise me when I see these lesions, and other colleagues tell me they see them," Brooks said.

An even higher rate of silent strokes might be expected in a study of black Americans, she noted. "They have a higher incidence of hypertension [high blood pressure], atherosclerosis, and hyperlipidemia [excess blood fat]," Brooks said.

Nothing special needs to be done to reduce the risk of silent stroke, Seshadri and Brooks both said.

"I wouldn't recommend that people rush out to have an MRI," Seshadri said. "It's up to the medical and public health community to emphasize the importance of controlling risk factors."

"The whole thing boils down to modifying risk factors," Brooks said. "If you don't have risk factors such as high cholesterol, obesity and diabetes, try to keep yourself out of the group that does. If you do, modify them by keeping blood pressure and cholesterol down, things like that."

More information

Detailed advice on preventing strokes is offered by the U.S. Centers for Disease Control and Prevention.

WEDNESDAY, June 25 (HealthDay News) -- Being well-off and well-educated may improve your chances of surviving a heart attack, according to new report.

Researchers at the Mayo Clinic, studying medical records of heart attack patients from its home base of Olmsted County, Minn., report that those with lower incomes and less education were more likely to die after the attack than their more affluent, educated counterparts.

The study, published in the June issue of Mayo Clinic Proceedings, looked 705 people -- 155 of whom died -- between Nov. 1, 2002 and May 31, 2006. Their findings include that:

• People with the lowest income had the worse one-year survival estimates, with 75 percent survival among people earning $28,732 to $44,665; 83 percent survival for those earning $49,435 to $53,561; and 86 percent for people in the $56,992 to $74,034 income bracket.
• The level of an individual's education also coincided with survival rates: 67 percent among those who had fewer than 12 years of education; 81 percent among people with 12 years of education; and 85 percent for those with more than 12 years of education.

"Interestingly, despite the higher-than-average socioeconomic status of this population, the associations of individual education and neighborhood income with death after heart attack were stronger than those reported in many previous studies," Mayo Clinic cardiovascular researcher Yariv Gerber, the study's lead author, said in a prepared statement.

The education link could be tied to how greater education tends to positively affect job opportunities, income, housing, access to nutritious foods and health insurance, the researchers noted.

"Higher levels of education also could directly affect health through greater knowledge acquired during schooling and greater empowerment and self-efficacy," Gerber said. "As recently reported, education is strongly associated with health literacy, which in turn affects one's ability to obtain, process, and understand basic health information and services needed to make appropriate health decisions."

The researchers also said linking low socioeconomic status to heart attack survival could be tied to poorer, less-educated individuals having difficultly attending cardiac rehabilitation programs and keeping up with medications and recommended changes in lifestyle.

More information

The American Heart Association has more about the warning signs of a heart attack  .

WEDNESDAY, April 16 (HealthDay News) -- The timing of hormone therapy might determine its effect on a woman's heart.

Specifically, researchers have found that hormone replacement therapy (HRT) administered early in menopause to women with risk factors for heart disease did not diminish the function of the endothelial cells that line the inner walls of the arteries and might even improve it. Endothelial function is a way to measure early heart disease.

"Hormone therapy might not be as bad as was once thought," said Dr. Suzanne Steinbaum, director of Women and Heart Disease at Lenox Hill Hospital in New York City. "It might even be helpful in women with risk factors."

However, there isn't enough evidence to suggest that women should start taking HRT to lower their risk for heart disease, the authors emphasized.

The researchers, from Virginia Commonwealth University Medical Center in Richmond, presented their findings Wednesday at the American Heart Association's Arteriosclerosis, Thrombosis and Vascular Biology annual conference in Atlanta.

A section of the U.S. government-sponsored Women's Health Initiative (WHI), which was designed to look at health issues in postmenopausal women, was halted in 2002, when U.S. researchers found that hormone therapy led to an increased risk of adverse events that included heart attack, stroke, breast cancer and blood clots. The risk depended on whether the woman was taking estrogen alone or estrogen plus progestin, another female hormone.

Since that time, however, a more complex picture has emerged with various factors, including amount of hormone as well as timing, having an effect on risks and benefits of HRT.

Previous research indicated that HRT might have a negative effect on cardiovascular health in women who started therapy long after menopause, versus women taking it sooner after menopause.

Before the WHI, many women took HRT in the belief that it would reduce their risk for heart disease.

For this study, researchers used ultrasound to measure flow-mediated dilation (FMD) in the brachial artery in four groups of postmenopausal women (127 participants total).

FMD measures how well the endothelium functions. The brachial artery is the main artery in the arm.

"Endothelial dysfunction is often associated with risk factors," Steinbaum explained.

There were four groups in all: One comprised of women not on HRT, with no heart disease risk factors and about eight years postmenopausal; women not on HRT but who did have risk factors for coronary disease and a little over nine years postmenopausal; women taking estrogen alone, with risk factors and almost 12 years postmenopausal; and women taking estrogen plus progestin and 7.6 years postmenopausal.

Most women had started HRT about the time menopause started.

Women with risk factors who took HRT saw a slight improvement in FMD and, on the whole, there were no reductions in blood vessel function.

More information

Visit the Women's Health Initiative for more on hormone replacement therapy.