American Heart Association 2003 year-end report
American Heart Association
American Heart Association's top 10 advances for 2003 include new blood pressure guidelines, novel blood thinners
Novel drugs for heart failure, new blood pressure treatment guidelines and the success of a public access defibrillation program are among the top 10 advances in heart disease and stroke for 2003, said Augustus O. Grant, M.D., Ph.D., president of the American Heart Association.
Other major milestones include a new blood thinner, a potent clot-busting substance extracted from the saliva of vampire bats, and a new approach to clear plaque from arteries.
Created in 1996, the "Top 10" list highlights major gains in heart disease and stroke research. The top 10 for 2003 include:
1. New high blood pressure guidelines create new at-risk classification. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC VII) said "prehypertension" is a new classification that includes people with blood pressures between 120-39 millimeters of mercury (mm Hg) systolic (the top number in a blood pressure reading) and 80-89 mm Hg diastolic (bottom number). Prehypertension is an ominous precursor to chronic high blood pressure, according to new guidelines released in 2003 by the federal government.
Lifestyle changes such as eating a healthy diet, exercising regularly and quitting smoking, can help to prevent, or at least postpone, the development of full-blown hypertension in patients with prehypertension. This may also reduce their risk of later developing heart disease, stroke and kidney disease, the guidelines state.
The guidelines also state that in people over age 50, systolic pressure greater than140 mm Hg is a more important cardiovascular disease risk factor than diastolic blood pressure. Therefore, people with a systolic pressure of 140 mm Hg or greater in that age group should be treated regardless of the diastolic blood pressure level.
Also, the guidelines suggest most hypertensive patients will require two or more antihypertensive medications to achieve goal blood pressure (less than 140/90 mm Hg, or less than 130/80 mm Hg for those with diabetes or chronic kidney disease).
High blood pressure (hypertension) affects about 50 million Americans and 1 billion people worldwide.
Citation: JAMA Express, June 14, 2003.
2. New blood thinner offers first potential alternative in 50 years. This year saw the introduction of a new, easier to manage blood thinner pill -- and the first potential alternative in 50 years to warfarin, the standard treatment given to millions of people to prevent blood clots.
In the Stroke Prevention Using the Oral Direct Thrombin Inhibitor Ximelagatran In Patients with Nonvalvular Atrial Fibrillation (SPORTIF V) trial, anticoagulation with warfarin, which reduces the risk of ischemic stroke and other systemic and embolic events in patients with atrial fibrillation (AF), was compared with the oral direct thrombin inhibitor ximelagatran. Patients with AF and at least one stroke risk factor (3,922 individuals) were randomized to receive adjusted-dose warfarin or fixed-dose oral ximelagatran. The primary endpoint was all strokes (ischemic and hemorrhagic) and systemic embolic events. Primary event rates were 1.2 percent/year in the warfarin group and 1.6 percent/year in the ximelagatran group, not a significant difference. When all-cause mortality was included with the primary events, the rate difference between groups by ITT was even less, at 0.10 percent/year. Rates of disabling or fatal stroke, hemorrhagic stroke and major bleeding did not differ significantly between groups, but combined minor and major bleeding was lower with ximelagatran (47 percent/year versus 37 percent/year). In this large, double-blind trial involving high-risk patients with AF, fixed-dose, oral ximelagatran was at least as effective as well-controlled warfarin for preventing stroke and systemic embolic events. It also resulted in less bleeding, confirming the results of the SPORTIF III open-label trial.
A second study found that ximelagatran may be more effective than warfarin in preventing blood clots after knee replacement surgery. In that study, 2,301 patients in five countries received low or high dose ximelagatran or warfarin for up to 12 days after surgery. Of these 2301 patients, 1,851 were included n the analysis of drug efficacy. Twenty percent of patients in the high-dose ximelagatran group developed clots or died, compared with 25 percent in the lower-dose group and 28 percent in the warfarin group.
Ximelagatran was developed as an alternative to warfarin in an effort to find a drug that was easier for patients and doctors to manage. While widely prescribed after strokes, heart attacks and knee surgery, warfarin requires close laboratory monitoring for dose adjustment, and interacts with certain foods and drugs. Studies show ximelagatran does not require adjustments or close monitoring, and has no food or drug interactions.
Citation: American Heart Association Scientific Sessions 2003.
The New England Journal of Medicine, Oct. 29, 2003.
3. Public defibrillators and trained volunteers are a lifesaver for cardiac arrest victims. Training volunteers to use automated external defibrillators (AEDs) distributed in shopping malls, sports venues and other high traffic public places can double the odds that cardiac arrest victims will survive, researchers reported at the American Heart Association's Scientific Sessions 2003 in Orlando, Fla.
Each year, an estimated 400,000 to 460,000 Americans die of heart disease in an emergency room or before reaching a hospital. Paramedics and firefighters are trained to use defibrillators to shock victims' hearts back to normal – if they arrive in time. But with only a 5-10 minute window of opportunity, most do not arrive in time.
The new study was designed to see if having AEDs available in public places for use by trained volunteers could improve the chance for survival. For the study, AEDs were placed in key locations at nearly 1,000 shopping centers, recreation centers, apartment complexes, entertainment complexes and community centers in 24 cities across the United States and Canada. The researchers then enlisted about 20,000 volunteers. All were taught to do cardiopulmonary resuscitation; half were also taught how to use the AEDs. Over the next 21.5 months, the volunteers attempted to resuscitate nearly 300 cardiac arrest victims. Forty-four survived, 29 of whom were treated by the volunteers who used the AEDs plus CPR and 15 of whom were treated by those who did CPR alone.
The results are so encouraging that they are expected to jumpstart efforts to get more AEDs in public places and train additional volunteers.
Citation: American Heart Association Scientific Sessions 2003, Plenary Session III, Late-Breaking Clinical Trials, Presented Nov. 11, 2003.
4. New treatment option for heart failure patients. People whose hearts have been weakened or damaged by a heart attack got a much needed new treatment option in October, when the U.S. Food and Drug Administration approved epleronone, a member of a class of drugs known as aldosterone blockers, for the treatment of congestive heart failure following a heart attack.
The approval was based in large part on the Eplerenone Post-Acute Myocardial Infarction Heart Failure Efficacy and Survival Study (EPHESUS), released in April.
The study of 6,632 patients showed that those who took eplerenone on top of standard congestive heart failure treatment were 15 percent less likely to die from any cause, 17 percent less likely to die from heart disease, and 13 percent less likely to die of heart disease or be hospitalized, compared with those who took placebo plus standard therapy. Standard treatment for congestive heart failure after a heart attack includes heart surgery, ACE inhibitors, aspirin, beta blockers and statins, according to the study authors.
More than a million Americans have a heart attack annually and about half (515,000) die. More than a third of heart attack survivors will develop heart failure, half of whom will die within five years. Epleronone blocks the actions of the hormone aldosterone in the body. High levels of aldosterone, which causes the kidneys to retain salt and water, are associated with increased risks in congestive heart failure patients.
Citation: The New England Journal of Medicine, April 3, 2003.
5. Heal thyself: Patients' bone marrow cells restore failing hearts. Bone marrow cells taken from patients' own blood healed heart muscle that was damaged during a heart attack, providing a new treatment for failing hearts, researchers reported at the American Heart Association's Scientific Sessions 2003 in Orlando, Fla. The bone marrow cells, which doctors infused directly into the patients' ailing hearts, fueled new heart cell growth, which strengthened the heart's pumping capacity. German researchers studied 40 heart attack patients in whom blood vessels had been treated with balloon angioplasty and into which a mesh tube called a stent had been placed to help keep it open. Twenty patients received the bone marrow stem cells; 20 others who declined the experimental procedure comprised the control group.
A few days after the patients' heart attacks, doctors obtained bone marrow cells from members of the treatment group. The cells were implanted into the damaged muscle, using a catheter threaded into a heart artery. Three months later, the stem cell patients had less heart muscle damage and an increased ejection fraction, a measure of the heart's pumping ability.
Other research teams are also investigating the use of stem cells harvested from bone marrow to reverse the muscle damage caused by a heart attack or to strengthen hearts that have been severely weakened over the years by congestive heart failure. Stem cells are immature cells that still can transform, or differentiate, into different types of cells, such as heart muscle and blood vessels. While the work is still early, it could eventually revolutionize the treatment of heart disease, researchers say.
Citation: American Heart Association Scientific Sessions 2003, Abstract P1929, Presented Nov. 10, 2003.
6. Drug-coated stents effective in "real world" patients. Drug-coated stents – which the American Heart Association in 2001 picked as one of the biggest potential breakthroughs in treating cardiovascular disease – are starting to live up to their promise, with researchers reporting in 2003 that the devices are safe and effective at preventing death, heart attack or repeat procedures in "real world" patients. People in the real world are often sicker or older than those selected for clinical trials.
One-year results from the Rampamycin-Eluting Stent Evaluated At Rotterdam Cardiology Hospital (RESEARCH) registry of 958 patients with previously untreated blocked arteries show that 9.7 percent of patients who received sirolimus-eluting Cypher stents had a major adverse cardiac event, compared with 14.8 percent of those who received bare stents. Only 3.7 percent of the patients treated with drug-eluting stents had a renarrowing of the treated vessel that required repeat procedures, while 10.9 percent of the patients in the bare stent group required repeat interventions.
Citation: Rapid access issue of Circulation: Journal of the American Heart Association. December 23, 2003.
7. Newly mapped gene for ruptured heart may lead to life-saving treatment. Researchers studying an inherited life-threatening heart disorder reported in 2003 that they had mapped a new location for a genetic mutation that causes the problem. The finding may lead to early, life-saving treatment for familial thoracic aortic aneurysm and dissection (TAAD), in which the aorta enlarges until it eventually bursts or dissects.
The aorta is the large artery that receives oxygen-rich blood from the heart. Arteries that branch from the aorta distribute blood to the rest of the body.
Currently people with TAAD are unaware of the risk they face because the slowly enlarging aorta does not cause any symptoms until it has reached a critical diameter. At that point, the aorta dissects or ruptures, both of which are life-threatening.
So researchers have been searching all the human genes to identify the genes responsible for TAAD. But they first needed to identify the chromosome sites of the genes. The team had already identified two chromosome sites: 5q13-15 (TAAD1) and 11q23.2-q24 (FAA1[familial aortic aneurysm]) – but some families had disease that could not be linked to these sites. In the new study, researchers examined four generations of one family of Swiss-German heritage which had a history of TAAD unlinked to the previously identified chromosome locations. Researchers collected and analyzed DNA samples from 52 family (from a fourth generation family) members and identified a new location for familial TAAD at 3p24-25. They named it TAAD2.
As researchers continue to search for other chromosome sites, they are also trying to pinpoint the exact mutant gene. Once the mutation is identified, researchers may develop tests to identify people who are at risk for familial TAAD. Then these high-risk people can be closely monitored so that they can undergo surgery to correct the disorder before the aorta is at risk for dissection.
Citation: Rapid access issue of Circulation: Journal of the American Heart Association, June 24, 2003.
8. Vampire bats yield potent clot buster. A clot-busting substance extracted from the saliva of vampire bats may significantly increase the number of ischemic stroke victims eligible for clot-busting treatment, Australian researchers reported in 2003.
That's because the clot buster, called Desmodus rotundus salivary plasminogen activator (DSPA), or desmoteplase, may be able to be used up to three times longer than the current stroke treatment window – without increasing the risk for additional brain damage. The vampire bat saliva-derived DSPA targets and destroys fibrin, the structural scaffold of blood clots, said Monash University researchers.
Ischemic strokes are caused when a blood clot or series of clots block blood supply to the brain. The only Food and Drug Administration-approved clot buster for treating ischemic stroke is intravenous tissue plasminogen activator, (rt-PA). However, rt-PA is administered to only a small percentage of patients because current protocols allow treatment only within three hours of stroke onset. Also, rt-PA has been shown to promote brain cell death in some animal studies.
Although most of the experiments with DSPA have been limited to animal studies, the novel clot buster is now being tested up to nine hours after stroke onset in a European study of human stroke patients, and a U.S. study could begin next year.
Citation: Rapid access issue of Stroke: Journal of the American Heart Association. Jan. 10, 2003.
9. A shot of good cholesterol may clear out blocked arteries. An experimental treatment that seems to reverse coronary artery disease made headlines in 2003, when Cleveland Clinic researchers reported that just five weeks of weekly infusions of a synthetic form of high-density lipoprotein, or HDL, cholesterol can remove significant amounts of plaque from fat-clogged arteries.
In the study, 57 patients with acute coronary syndromes defined as unstable angina, non-ST-or ST elevation myocardial infarction were randomly assigned to treatment with a synthetic version of HDL known as apolipoprotein Milano AI/phospholipid complexes (ETC-216) or control groups. They were given intravenously once a week. A total of 47 patients completed the study, 11 in the placebo group and 21 in the low-dose and 15 in the high-ETC 216 groups.
The synthetic substance mimics a naturally occurring genetic variation found in a small group of people living in northern Italy that appears to protect against atherosclerosis. As determined by intravascular ultrasound at baseline and six weeks after treatment, the volume of fatty deposits in the arteries (atheroma) decreased by an average of 1.06 percent in the combined group that got the ETC-216 infusion. In contrast, in the placebo group, atheroma volume increased by 0.14 percent.
While the numbers are small, researchers said that no treatment to date has been associated with regression of plaque in such a short amount of time. Stay tuned.
Citation: Journal of the American Medical Association, Nov. 5, 2003.
10. How to use a new blood test to measure heart attack risk. For the first time, a panel of experts convened by the American Heart Association and the Centers for Disease Control and Prevention recommended in 2003 limited use of a new blood test for assessing heart disease risk. The test measures C-reactive protein, or CRP, a marker of inflammation. Several studies have demonstrated that increased concentrations of CRP appear to be associated with increased risk for coronary heart disease, sudden death and peripheral arterial disease.
The writing group emphasized that the new test – known as highly sensitive C-reactive protein (hs-CRP) test – does not fit in the same category as cholesterol testing or high blood pressure screening currently recommended. They said the test might be useful when a physician is undecided about a course of treatment for a patient who is considered intermediate risk.
Citation: Print issue of Circulation: Journal of the American Heart Association. January 28, 2003.
For more information, or to contact American Heart Association, see their website at: www.americanheart.org
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