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WEDNESDAY, Dec. 20 (HealthDay News) -- The sophisticated biomarkers for cardiac risk that have enthralled researchers in recent years don't add much diagnostic power to such traditional risk factors as blood cholesterol levels, smoking, blood pressure and obesity, a new study finds.

"Our results indicate that, at least for clinical use, they are not ready for prime time," said study author Dr. Thomas J. Wang, an assistant professor of medicine at Harvard University and a member of Massachusetts General Hospital's cardiovascular division. The report is published in the Dec. 21 issue of the New England Journal of Medicine.

Wang and his colleagues followed 3,209 participants in the Framingham Heart Study for a decade, measuring biomarkers that included C-reactive protein, homocysteine, urinary albumin, fibrinogen and natriuretic peptides.

While those measurements did provide indicators of increased risk of cardiovascular disease, "a lot of biomarkers don't seem to add a great deal once you take the standard risk factors into account," Wang said.

But research on those biomarkers should continue, because "there very well could be subgroups of people in which it would be useful to measure biomarkers," Wang said. "We need further data on that question."

Another reason for continuing research is that "there are studies that suggest that treating people to lower these biomarkers improves clinical outcome," he said.

But the bottom line is that "widespread use of biomarkers is not indicated at this time for clinical purposes," Wang said.

"The message in the article is that the cycle of enthusiasm and hope that we have found the holy grail has been shot down," said James H. Ware, dean for academic affairs at the Harvard School of Public Health, who wrote an accompanying commentary.

Researchers have tended to hope that a newly discovered biomarker "might be a great advance in the ability of a doctor to take individual patients and make a diagnosis," Ware said. "But a lot of these things don't have much use as diagnostic tools."

"People will be more cautious as new biomarkers emerge," he added.

But research should continue because "diseases like cardiovascular disease are very complicated, multi-factorial phenomena," Ware said. "There is not one pathway that leads to impairment of the heart, so a description of it is bound to be complicated."

One useful lesson of the study is that "our data provide a useful reminder that traditional risk factors are very important," Wang said. "They set the bar very high in terms of the knowledge they give us. It takes a fair amount to improve on what we already have."

More information

The known risk factors for cardiovascular disease are listed by the American Heart Association  .

WEDNESDAY, Dec. 13 (HealthDay News) -- An important molecular process that can cause plaque rupture in people with atherosclerosis has been identified by Columbia University Medical Center researchers.

The findings could lead to therapies to prevent plaque rupture, which can produce clots that may block blood flow and cause heart attacks and strokes.

The Columbia team identified what causes the death of macrophages, which are white blood cells that accumulate in the cholesterol-laden plaques on the inside of arteries. These dead macrophages, which collect into a "macrophage graveyard," are an important cause of plaque rupture.

This study found that macrophages in the plaques die when two receptors on the cell's surface -- TLR4 and SRA -- are activated at the same time. When it's activated alone, TLR4 keeps the macrophage alive. However, when SRA is activated at the same time, it shuts down TLR4, leading to the death of the macrophage.

The findings were published Dec. 11 in the journal Proceedings of the National Academy of Sciences.

Until recently, scientists had hoped that drugs that increase "good" HDL cholesterol, used in combination with statins that reduce "bad" LDL cholesterol ,might help treat atherosclerosis patients. However, the recent failure of an experimental drug designed to increase HDL levels suggests that it may not be possible to rely solely on drugs that raise HDL levels to prevent plaque rupture.

"The recent failure of an HDL boosting therapy means it's particularly important for us to consider alternative strategies and to understand the process behind the rupture of plaques," Dr. Ira Tabas, professor of medicine and anatomy and cell biology, said in a prepared statement.

"Our hope is that this research will lead to alternative therapies to prevent plaque rupture and resulting strokes and heart attacks," said Tabas, who is also Richard J. Stock Professor and vice chairman of research at Columbia University Medical Center.

More information

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

WEDNESDAY, Dec. 13 (HealthDay News) -- Ischemic stroke patients who have recurrent asymptomatic brain lesions within three months of their initial stroke are at increased risk for subsequent strokes, says a U.S. study in the December issue of the journal Archives of Neurology.

An ischemic stroke occurs as a result of inadequate blood flow to the brain.

Previous research found that asymptomatic (silent) brain lesions -- changes in brain tissue that occur in areas where blood flow is blocked or reduced -- occur more frequently than symptomatic lesions up to three months after a stroke, according to background information in the article.

The authors of this current study investigated whether silent brain lesions detected by MRI scans could help predict stroke patients' risk for subsequent strokes.

Researchers at the National Institute of Neurological Disorders and Stroke studied 120 ischemic stroke patients. Each patient had an MRI brain scan within 24 hours of the stroke and five days after the stroke. Of those patients, 68 had a follow-up MRI after 30 days or up to 90 days after the stroke.

The study found that patients who had silent ischemic lesions on the 30- or 90-day MRI were about 6.5 times more likely than other patients to suffer a subsequent ischemic stroke. Patients with silent lesions on any of the MRI scans (24 hours, five days, 30 days, or 90 days) had an increased risk of death from vascular causes, recurrent ischemic stroke or transient ischemic attack.

"It is a matter of circumstance, rather than tissue pathological features, that determines whether cerebral ischemia is symptomatic or silent," the study authors wrote. "Clinical symptoms depend on the size, location and number of new lesions. Thus, we assume that the pathological process that causes silent lesion recurrence on MRI is the same as the process that causes clinical recurrent strokes. Magnetic resonance imaging may depict pathological changes before the development of clinical stroke symptoms."

More information

The Washington University School of Medicine has more about ischemic stroke  .

MONDAY, Dec. 11 (HealthDay News) -- More Americans, especially the elderly, now have their blood pressure under control, a new study finds.

"It is hard to attribute the improvement to any particular factor," said study author Bernard M.Y. Cheung, an associate professor of medicine at the University of Hong Kong. His report appears in the Dec. 12 issue of Hypertension. "We have tried to see if the explanation lies in better awareness, detection or treatment. There is no statistically significant increase in these, so probably all of these contribute in a small way."

Whatever the reason, the numbers from the National Health and Nutrition Examination Survey 1999-2004, which include more than 14,500 people, tell an encouraging story. Hypertension -- high blood pressure -- is a major risk factor for heart attack, stroke, heart failure and kidney failure. In the study, blood pressure was regarded as being under control at a reading below 140/90, or 130/80 for people with diabetes.

From 1999-2000 and 2003-2004, the percentage of Americans aged 60 and older who met those criteria rose from 26.4 percent to 36.7 percent, the study found. Awareness of the importance of blood pressure control rose from 70.6 percent to 81 percent, and treatment rates improved from 63.8 percent to 73.4 percent.

Improvement in some specific groups was notable. Control rates for obese people rose from 25.1 percent to 36.2 percent, and more than doubled for people with diabetes, from 15.7 percent to 33.2 percent.

But there were some dark spots in the picture. A quarter of those with high blood pressure were unaware they had it, and about a third of those with high blood pressure were not being treated in 2003-2004.

"We found that adults below the age of 40 often do not know they have hypertension, whereas awareness of hypertension is high among the elderly," Cheung said. "This is unfortunate, because hypertension in the younger age group is relatively easy to control."

What is needed to improve the picture is "getting everyone, including those who are young and without symptoms, to be screened for high blood pressure," he said.

The report was called "great news" by Dr. Henry Black, president-elect of the American Society on Hypertension and a professor of preventive medicine at Rush University Medical Center in Chicago.

"What we've been doing for the last half-dozen years has been working," Black said.

What is needed now "is more of the same," Black said. "We've got to get the population a little thinner and a little more active. And we want to treat people at lower levels of hypertension more aggressively, so they don't get into danger."

More information

A guide to lowering high blood pressure is offered by the U.S. National Heart, Lung, and Blood Institute.