TUESDAY, Dec. 4 (HealthDay News) -- A test of two heart functions accurately spotted patients at highest risk of cardiac arrest or death as they recovered from a heart attack, Canadian researchers report.

"This is important because past studies, focusing on a single test, failed to identify most people at risk," said study lead author Dr. Derek V. Exner, associate professor of medicine at the University of Calgary. "We developed a simple method of identifying approximately twice as many people at risk. That means we can potentially save more lives."

The tests used in study are available now, although they aren't widely used, Exner said. "Theoretically, we can do them today if we chose to," he said. But the plan is to wait for the completion of additional trials, such as two large-scale studies now in the planning stage.

In the study, Exner and his colleagues had 322 people wear monitors for 18 to 24 hours a day, starting two to four weeks after they had suffered a heart attack. The researchers looked at the electrocardiograms recorded by the devices for an abnormality in heart rhythm called T-wave alternans, a symptom so subtle it can be detected only by computer analysis.

In addition to that measure of heart function, the electrocardiograms were also analyzed for the presence of heart rate turbulence, an abnormality of the autonomic nervous system that controls heart function.

Starting at 10 to 14 weeks after the heart attack, the presence of the two abnormalities clearly identified persons at increased risk. The 20 percent of study participants who had both abnormalities had more than six times the risk of cardiac arrest or death than other people in the study, the researchers said.

The findings are published in the Dec. 11 issue of the Journal of the American College of Cardiology.

Previous studies have shown that one abnormality or the other can increase cardiovascular risk, said Dr. David S. Rosenbaum, professor of medicine at Case Western Reserve University, who first reported on T-wave alternans in 1994.

"This is where this paper extends our knowledge," Rosenbaum said. "It shows that the two [irregularities] have a synergistic effect in a post-myocardial infarction [heart attack] population."

One application of the two-in-one testing could be in selecting persons who would be best helped by an implantable defibrillator, a device that delivers a shock to keep the heart beating normally when necessary. In the majority of cases today, Rosenbaum said, an implanted defibrillator just sits in the chest, because its emergency activity is never needed.

Exner said: "We have two large studies planned. One is where we have patients who are not indicated for defibrillators post-MI [myocardial infarction]. It is starting in May. The other study will include patients getting defibrillators because of a low ejection fraction," a weakened ability to pump blood.

Until these and other studies are done, "it's too early to start making treatment decisions" on the basis of the two combined tests, Exner said.

Rosenbaum said the new study does show "that when you combine these tests, you get a fairly robust prediction of outcomes. But like all good studies, it raises a lot of questions. It also requires validation in prospective trials."

More information

To learn more about implantable defibrillators, visit the American Heart Association  .

TUESDAY, Dec. 4 (HealthDay News) -- A newer kind of anticlotting drug is safe over the long run when used during coronary emergencies such as heart attacks.

The drug, a "direct thrombin inhibitor" called bivalirudin, is used to keep blood flowing freely during cardiac procedures such as bypass surgery.

"We had a lot of success reducing complications with this class of drug," said study co-researcher Dr. A. Michael Lincoff, director of cardiovascular research at the Cleveland Clinic.

The team reported its findings in the Dec. 5 issue of the Journal of the American Medical Association. The study was funded by The Medicines Company of Parsippany, N.J., and the Danish company Nycomed, which have each helped develop bivalirudin.

The news may be important for the two million or more Americans who undergo bypass operations and similar procedures each year, Lincoff said. Bivalirudin not only reduces the incidence of excess bleeding that can be associated with anticoagulant use, it also is less expensive than older anticoagulant drugs, he said.

Those drugs, called GP IIb/IIIa inhibitors, act on platelets, blood cells involved in clotting. The new agent used in the trial, bivalirudin (brand named Angiomax), acts directly on molecules such as thrombin that cause clotting.

"Previous studies with patients in elective situations have shown that bivalirudin was just as effective at reducing bleeding," Lincoff said. "The question was whether it held for patients with unstable heart disease over the long run."

The study looked at the use of anticoagulants in patients undergoing procedures for conditions collectively known as acute coronary syndromes.

First results of the trial, which included 13,819 people who underwent procedures at 450 institutions, showed no difference in outcomes within the first month after surgery. And the current report found no significant difference over the year that followed the procedure. For example, all-cause mortality was 3.9 percent for those using the older drugs versus 3.8 percent for those who got bivalirudin. The mortality rate for patients who got combined therapy with the older drugs and bivalirudin was 3.9 percent.

The major advantage of bivalirudin is that it decreases the incidence of excess bleeding -- always a problem when anticoagulants are used, Lincoff said. Excess bleeding during a procedure is associated with a higher risk of long-term mortality.

"About 4 to 5 percent of patients have bleeding complications from older anticoagulant use," Lincoff said. "With 1.25 million hospital admissions a year for acute coronary syndromes and over one million a year for non-emergency procedures, that is quite a large number."

Bivalirudin has a number of advantages over the older treatment, said Dr. Gregg W. Stone, professor of medicine at Columbia University and lead author of the journal report.

"It causes much less bleeding, it leads to less need for blood transfusions, it leads to more streamlined care and less expensive hospital costs," he said. "Now this new data coming in suggests that it can reduce mortality and save lives.

Stone said he is using the drug in about 95 percent of his cases. In the other 5 percent, fear that a blood vessel might rupture leads to use of heparin, an anticoagulant whose activity can be reversed quickly to prevent a major hemorrhage.

Dr. Christopher Granger, professor of medicine at Duke University Medical Center, said the one-year report is "important because it really reinforces what we learned from the 30-day report from the trial. Any differences in outcome seen early didn't result in changes in how we interpreted those outcomes in the long run."

The initial report showed a slight increase in blood vessel blockage and a 50 percent reduction in bleeding episodes with bivalirudin, Granger said. "The question was, does it make a difference?" he said. "The answer from this manuscript is that it doesn't. The effects neutralize each other.

"Bivalirudin is a particularly attractive option for patients showing up in the catheter lab early with a coronary syndrome," he said.

More information

There's more on acute coronary syndromes at the American Heart Association  .

THURSDAY, Nov. 15 (HealthDay News) -- Depression is known to hike the risk of cardiovascular disease, but don't put all the blame on any concurrent rise in inflammation.

So concludes a study led by Dr. Viola Vaccarino, a professor of medicine at Emory University, in Atlanta.

That means that it's back to the drawing board in terms of unraveling the depression-heart disease link, according to Vaccarino.

"That depression is a factor in cardiovascular disease is clear. What is not clear is what kind of mechanism is involved," she said.

The Emory group, as well as researchers from five other medical institutions, studied the possible role of inflammation in a group of 559 women who were referred for heart tests because of blockage in a coronary artery. All the women had a standard test for depression at the start of the study and were followed for an average of about six years.

They were divided into three groups on the basis of those tests: those who clearly were depressed by diagnosis and previous treatment; those who might be depressed because of either a diagnosis or treatment; and those who had no indicator of depression.

The researchers made frequent measurements of two molecules linked to the inflammatory response -- C-reactive protein (CRP) and interleukin-6.

There were 79 major events of cardiovascular disease during the study, 23 of them fatal.

As expected, the incidence of such events was 2.5 times higher in women with depression. There was no comparable increase in women classified as possibly depressed.

The team found that women diagnosed as depressed had a 70 percent higher level of C-reactive protein and a 25 percent higher level of interleukin-6 compared to women who were not depressed. Women classified as possibly depressed had elevated levels of both markers, but to a lesser extent.

The bottom line, according to the researchers, was that while inflammation was tied to heart risk, it failed to explain most of the cardiovascular danger posed by depression.

"Despite being associated with each other, depression and inflammation predicted future events for the large part independently," the researchers wrote. "Thus, despite a clear relationship between depression and inflammation, the latter plays only a minor role in the higher risk of adverse outcomes for women with depression."

The finding is something of as surprise, said Dr. David S. Sheps, professor of medicine at the University of Florida at Gainesville, a member of the research team.

"We know from other studies that there is a relationship between depression and elevation of certain inflammatory molecules, but no one knows for sure what the mechanism is," Sheps said.

"What is clear is that inflammation does not play a substantial role," Vaccarino said. "We need to look at other things. Perhaps there is a change in the ability of platelets to aggregate." Platelets are blood cells that can form clots to block arteries. "And there could be other pathways," she said.

More information

There's more on C-reactive protein and heart disease at the American Heart Association  .

MONDAY, Nov. 12 (HealthDay News) -- Patients who've suffered a minor stroke -- called a transient ischemic attack, or TIA -- have a substantial risk of suffering a major stroke within seven days.

But that risk of a second, bigger stroke is lowest among TIA patients treated as emergency cases in specialist stroke units, says a new British review of previous studies that included a total of 10,126 patients.

The researchers concluded that there's a 5.2 percent risk of a major stroke within seven days of a TIA, meaning that about 1 in 20 TIA patients will have a major stroke within a week. But the risk among TIA patients who received emergency care in specialist stroke units ranged from 0 percent to 9 percent, while the highest risk -- 11 percent -- was for patients who didn't receive emergency care.

The findings were published online Nov. 11 in The Lancet Neurology, and will appear in the December print issue of the journal.

"The risk of stroke reported amongst patients treated urgently in specialist units was substantially lower than risks reported among other patients treated in alternative settings. These results support the argument that a TIA is a medical emergency and that urgent treatment in specialist units may reduce the risk of subsequent stroke," said the study authors, from Oxford University's Stroke Prevention Research Unit.

Studies of major stroke risk after TIA have produced conflicting findings, with seven-day stroke risk ranging from 0 percent to 12.8 percent. The inconsistent findings among the previous studies that were included in the new review could be explained by differences in study method, setting and treatment, the review authors said.

"Our study almost fully explains why the results of previous studies have been conflicting and illustrates the importance of methods used by a medical study when interpreting its results," they concluded.

The researchers said reliable estimates of major stroke risk following a TIA could maximize the benefits of early treatment, allow effective planning of service for patients, assist in the design of clinical trials, and justify investment in public education.

Another expert, Dr. Keith Siller, medical director of New York University Medical Center's Comprehensive Stroke Care Center, called the study important for several reasons.

"The significant recurrence rate of a second more serious stroke within only one week's time shows that a patient with a minor stroke or TIA is not 'out of the woods' just yet and still remains at risk for an even worse stroke that mandates urgent hospitalization to expedite their evaluation even though they may appear to be back to normal," Siller said. "This is analogous to a patient with chest pain who may be having angina as a warning for impending heart attack and is admitted for additional testing to avoid sending them home and having them suffer a fatal heart attack outside the hospital."

Siller, who's also an assistant professor at the NYU School of Medicine, added that the study also emphasizes that "patients with TIA or minor stroke should be treated in stroke centers with specialized units since the care provided is specifically targeted for stroke and does result in better outcomes compared to a general medical ward."

What's more, Siller said, "these results need to be understood by insurance companies and HMOs that have unofficially discouraged doctors from admitting these same patients and prefer them to be worked up electively as outpatients. The reality is that completing all of the necessary testing as an outpatient within one week is often not possible, during which time the patient may have the second more devastating stroke that might have been prevented had they been in the hospital setting."

More information

The American Heart Association has more about TIA  .