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Breakthroughs in Cardiac Care

Researchers question effectiveness of stents

By JOHANNA JOHNSON
In WebMD Medical News, Daniel DeNoon reviewed findings that drug-coated stents, used for treating blocked arteries, may actually increase the risk of heart attack or cardiac death. Newly developed drug-coated stents have been preferred to bare-metal stents because they release powerful drugs that are intended to keep arteries from reclogging after balloon angioplasty. Recent reports, however, have shown that patients treated with drug-coated stents have a 0.5 percent greater risk of thrombosis, or blood clot formation, than patients with bare-metal stents. Nevertheless, the effectiveness of drug-coated stents in lowering the risk of stent blockage seems at this time to outweigh the small risk of lethal blood clots.

Trans Fats Lead to Heart Disease

Findings from the Nurses' Health Study, presented at the American Heart Association's annual meeting, conclude that trans fats have harmful effects on the heart. Data from the study indicates that the risk of developing heart disease was three times greater for women in the highest quartile of average consumption of trans fat per 1,000 calories a day than for women in the lowest quartile. Trans fat is prevalent in most processed foods, but may be easier to avoid now that the FDA requires trans fat amounts to be listed on all packaged foods.

Pulsating Cardiac Muscle Cells

Researchers at the University of Michigan recently discovered a new technique for growing bioengineered heart muscle (or BEHM) that can create pulsating forces and respond to stimulation similar to a natural heart muscle. The technique, which utilizes biodegradable fibrin gel and rat cardiac muscle cells, produced quicker and better results than previous attempts. The development of this new method for growing BEHM may eventually lead to the creation of muscle parts to replace damaged human hearts or even generate a whole new heart. The study is published online in the Journal of Biomedical Materials Research Part A.

Moderate Alcohol Intake May
Increase Good Cholesterol

Researchers at the Harvard School of Public Health published a study in the January 2, 2007, issue of the Annals of Internal Medicine suggesting that moderate alcohol intake—defined as one or two drinks a day—in hypertensive men actually reduced the likelihood of having fatal and nonfatal heart attacks. In addition, no differences in the amount of incidences of strokes and deaths from heart disease were found between nondrinkers and moderate drinkers in hypertensive men. One possible explanation is that a moderate amount of alcohol increases levels of good cholesterol and helps in thinning blood and preventing lethal blood clots. However, individuals are cautioned to avoid consuming three or more drinks a day, which may raise blood pressure levels and increase the risk of heart attack.

Low Carbohydrate Diets Better

According to an article in the November 9, 2006, issue of The New England Journal of Medicine, low-carbohydrate diets that are higher in protein and fat do not increase the risk of coronary heart disease in women. In addition, data analysis indicates that low-carbohydrate diets in which vegetables are the primary source of protein and fat may lower the risk of coronary heart disease in women.

Nitrate-rich Vegetables and Fruits Reduce Blood Pressure

The DASH diet, Dietary Approaches to Stop Hypertension, recommends consuming a large amount of fruits and vegetables. A Swedish study published in the December 28, 2006, issue of The New England Journal of Medicine suggests that the nitrates found in these foods may be the primary reason for the diet's effectiveness in reducing blood pressure. In this study, for three days, 17 physically active, healthy volunteers were administered either a placebo or a nitrate supplement equivalent to the amount found in about 150-250 g of vegetables rich in nitrate. Data revealed that, although systolic blood pressure did not differ in the two groups, individuals taking the nitrate supplements had a diastolic blood pressure that was on average 3.7 mm Hg lower than individuals receiving the placebo. However, more research will be done before nitrate supplements can be recommended for hypertensive patients.

Published: January 28, 2007
Issue: Winter 2007