Feb-04

Hispanic Teens Face High Chances of Heart Disease, Diabetes An alarming number of Hispanic pre-teens have at least one risk factor for cardiovascular disease or type 2 diabetes. One study found three in 10 Hispanic pre-teens have metabolic syndrome, which comprises numerous risk factors for type 2 diabetes and cardiovascular disease. The risk factors associated with metabolic syndrome include: high blood pressure; low levels of HDL cholesterol; central obesity; elevated triglycerides; and impaired glucose tolerance. This high rate of metabolic syndrome may be due to the fact that obesity is particularly common among Hispanics, the researchers suggest. They note that 35 percent of young Hispanics are overweight, about twice as many as a decade ago. The second study found that nearly three of 10 Hispanic pre-teens (28 percent) already have impaired glucose tolerance (pre-diabetes), putting them at a heightened risk of developing type 2 diabetes. Obesity is now a critical, common nutritional problem in children, researcher Michael I. Goran, a professor of preventive medicine and physiology and biophysics at USC's Keck School of Medicine, says. These studies show that the likely common pathway linking obesity to increased risk for type 2 diabetes and cardiovascular disease is insulin resistance. Our results show that this link is established early in life, Goran says. Gene Tied to Inflammatory Attack on Arteries California researchers have discovered a gene that can increase the risk of heart attack and stroke by launching an inflammatory attack against blood vessels. For people who carry the gene, the finding reinforces a standard dietary recommendation for keeping arteries healthy: Eat more oily fish, such as salmon. That advice is aimed at reducing blood levels of one sort of fatty molecule, low-density cholesterol. This time, the idea is to avoid foods containing n-6 polyunsaturated fatty acids, a class of fats that set off the inflammatory reaction. However, a different class of polyunsaturated fatty acids designated n-3, which are found in fish suppress the inflammatory response. Inflammation has been big news in cardiovascular research recently. Study after study has shown that high blood levels of C-reactive protein are associated with increased risk of artery damage. But until now, no one has known why the inflammatory attack occurs. This is the first example of how a gene that causes inflammation is involved in artery blockage, says Hooman Allayee, a fellow in the human genetics department of the University of California at Los Angeles and leader of the team reporting the finding. Allayee and his colleagues have found a fairly common form of the gene for 5-lipoxygenase, a molecule involved in the body's defense against injury, can be activated by fatty acids in the diet to attack the arteries. A study of 470 healthy Los Angeles residents found that about 6 percent of them carry the potentially dangerous form of the gene, Dwyer says. Detailed studies shown abnormal thickening of artery walls in the people with that form of the gene. People who carry the dangerous version of the gene should avoid foods containing two n-6 polyunsaturated fats, arachidonic acid and linoleic acid, all of which stimulate the inflammatory activity, Dwyer says. Organ meats liver, heart, giblets should be avoided because they have high levels of arachidonic acid. Vegetable oils from corn and soybeans should be avoided because they are rich in linoleic acid, he says. Olive oil is preferable because it has a lot of n-3 polyunsaturated fatty acids, which prevent inflammation. The gene is more prevalent in people of non-European ancestry, such as blacks and Asians, Dwyer says. About 10 to 20 percent of them have this form of the gene. Specific dietary and pharmaceutical intervention should be effective in this group. The variant form of the gene seems to make a normal process of repairing injury to an artery become dangerous, Dwyer says. If our findings are confirmed to show that people carrying this genotype are at increased risk, it won’t be long until we have a routine clinical test to detect it, he says. But these are early days, Dwyer adds. We need a lot more practical experience. Cook Incorporated Introduces Zilver 518 Biliary Stent The Zilver 518 Biliary Stent, a flexible, self-expanding nitinol design intended to treat patients with malignant neoplasms in the biliary system, is now available from Cook Incorporated following clearance by the U.S. Food and Drug Administration. The Zilver 518 provides physicians with a 5 French-compatible, lower profile system delivered over a .018 inch wire guide to facilitate its use in smaller lumens. The Zilver 518 Stent incorporates Cook’s patented Z-Stent cell design for radial strength while maintaining an equally distributed radial force throughout the stented area of the vessel. The fine mesh, slotted tube Zilver stent design displays kink resistance with the flexibility needed in the biliary duct upon deployment. The Zilver 518 Stent also has multiple gold radiopaque markers at each end to enhance visibility under fluoroscopy and zero percent foreshortening during deployment. Heart Patients Look to Cobra Venom Coumadin may soon have to make way for a new drug that seems to work more predictably and safely. Patients will have researchers to thank, along with a not-quite-usual suspect: the cobra. The drug, derived from cobra venom, is expected to reach pharmacies within 18 months under the brand name Exanta. Its manufacturer announced last week it has submitted the drug to the U.S. Food and Drug Administration (FDA) for approval. Experts say the drug could save time and reduce risks for millions of patients who face potential heart attacks and stroke. It would bring a dramatic change to how cardiologists practice, says Dr. Jonathan Halperin, a professor of medicine at Mount Sinai Medical Center in New York City. This would be an important step forward if the drug is safe and available. The problem with warfarin is that everybody absorbs it a little differently. People have to have frequent blood monitoring to adjust the dose, says Dr. Howard Herrmann, director of cardiac catheterization and interventional cardiology at the University of Pennsylvania. The blood tests are typically required at least once a month. If patients and doctors don’t work together to keep an eye on the levels of Coumadin in the body, the blood can become too thin or too thick. Since Coumadin works by interfering with the body’s absorption of vitamin K from food, even a minor change in a person’s normal diet can disrupt Coumadin levels. To make matters more complicated, Coumadin interacts with a variety of drugs, making them work improperly or vice versa. Antibiotics are frequent offenders, as are drugs used to control high cholesterol, Halperin says. There are hundreds if not thousands of drugs. The list alone goes on for five pages. Essentially, Halperin says, a more effective anticoagulant is needed, especially for patients for whom aspirin isn’t sufficient. Here’s where Exanta, also known as ximelagatran, comes in. It’s derived from the venom of the cobra, which seems to render victims powerless by thinning their blood. While it has not received federal approval yet, recent studies have reported the drug manages to thin the blood at a steady level without major fluctuations, unlike Coumadin. Patients wouldn’t need to undergo regular blood tests to check the thinness of their blood. It’s given in a fixed dose, and has no significant food or drug interactions, says Halperin. It’s almost like one-size-fits-all. The drug’s manufacturer, AstraZeneca, is seeking FDA approval to offer the drug as a treatment for people with atrial fibrillation and others at risk of blood clots. Experts caution however, that while Exanta may be a great improvement upon Coumadin, it won't be perfect. The drug appears to affect liver enzymes in about 6 percent of patients, although they did fine later, Halperin says. It will be appropriate that people who begin should have certain blood tests taken from time to time to make sure they and the medicine are getting along well with one another, Halperin says. Then there’s the matter of cost. New drugs, not surprisingly, typically cost much more than drugs that are a half-century old. But experts say doctors will save time by not having to order and review monthly blood tests. More cost savings could come if fewer people have strokes because Exanta is easier to use than Coumadin. According to the manufacturer of Exanta, studies have shown blood thinners reduce the incidence of stroke by 62 percent in patients at risk, but only half of them get the optimal treatment. Medtronic Announces Market Release of Two Left-Heart Delivery Systems Designed to Help Navigate Challenging Heart Anatomies Attain Prevail Steerable and Attain Deflectable Catheters Provide Maximal Support for Left-Heart Lead Delivery During Cardiac Resynchronization Therapy Implant Procedures Medtronic, Inc. announced the market release of two new Attain left-heart delivery systems, both designed to facilitate placement of left-heart leads during implantation of CRT devices. The Attain Prevail Steerable catheter system and the Attain Deflectable catheter system are specifically designed to help physicians navigate challenging heart anatomies during implant. The two new systems are designed to enhance cannulation of the coronary sinus as well as assist with cardiac vein subselection. The Attain Prevail system combines steerability, catheter telescoping and vein subselection. It allows the user to create multiple curve shapes without changing guide catheters, and also permits deep advancement of the guide catheter and guide wire. In addition, its soft, tapered tip design and small size (7 French), helps minimize the chance of venous trauma. The Attain Deflectable guiding catheter provides physicians with an opportunity for successful coronary sinus cannulation and left-heart lead placement. Implanters are able to vary the catheter curve to match a patient’s anatomy and, once cannulation has been achieved, the Attain Deflectable provides a workstation for the passing of guidewires, leads and venogram balloon catheters for greater visualization of the cardiac venous anatomy. Both new delivery systems allow contrast injection through the lumen to help visualize the anatomy, especially the cardiac veins on the left ventricle. The Attain Prevail can be inserted into straight or other fixed shape catheters to accomplish telescoping techniques, and the Attain Deflectable allows for adjustable curve reach and telescoping with a guidewire and over-the-wire lead. Attain leads and delivery systems are used with implantable cardiac resynchronization therapy devices such as the InSync® III CRT pacing system and the InSync II Marquis system that also includes a defibrillator. Hard Water is Good for Your Heart: Finnish Study That water is a basic necessity of life is nothing new, but Finnish health researchers reported that drinking hard water can actually help people avoid early death from cardiovascular disease. There are regional differences in the chemistry of the ground water that correlate with the incidence of heart disease, said Pekka Puska, director general of the Finnish National Health Institute. The study shows that the softer the water is, the more heart disease there is, he added. While researchers have been aware of this phenomenon for some time, most studies done so far have been very general. The new research is the first detailed survey, covering 19,000 incidents of heart attacks across Finland, and then linking them to geochemical data of the drinking water in the communities where the incidents had occurred. Whether water is hard or soft depends on the quantity of mineral salts, typically magnesium, calcium, zinc, copper, aluminum, fluoride and iron, dissolved in it. Normally hard water is described as containing more than 250 parts per million (PPM) of mineral salts, while mineral water typically has 500 PPM. Research from the west and south of Finland, where the drinking water is hard, found far fewer incidents of cardiovascular diseases than was the case in the north and east of the country, where the drinking water is soft. The researchers did not single out which of the minerals contributed to the effect, Puska said.

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