A new anti-clotting drug may improve the treatment of patients who have had heart attacks and chest pain but is not as effective as an existing drug, according to two new studies.
Both the new drug, tirofiban, and the existing drug, abciximab, are members of a new class called glycoprotein IIb/IIIa inhibitors, which bind to receptors on the surface of blood platelets to prevent them from aggregating into clots.
In the first study, an international team led by Dr. Christopher P. Cannon of Brigham and Women's Hospital in Boston studied 2,220 patients who had had chest pain or a heart attack. Half received aggressive treatment that included angioplasty to open the blocked artery, stenting to hold the artery open, and tirofiban, tradenamed Aggrastat. The other half received only conventional drug therapy, including clot-busters and other blood-thinning agents, but not tirofiban. Normally, said Cannon, angioplasty and drug therapy have about the same success rate. But when tirofiban was added to the aggressive treatment regimen, the team reported in the June 21 New England Journal of Medicine http://(www.nejm.org),the risk of death or a subsequent heart attack was reduced 26%.
An editorial in the journal by Dr. William E. Boden and Dr. Raymond G. McKay of Hartford Hospital in Connecticut concluded that aggressive therapy that incorporates the new family of drugs "should become the standard of practice" in such patients.
But which drug to use? A second study led by Dr. Eric Topol of the Cleveland Clinic Foundation compared tirofiban directly to abciximab, tradenamed ReoPro, in 4,809 patients who received one drug or the other before undergoing angioplasty and insertion of a stent.
The team reported in the same issue of the journal that the death rate was 21% higher among patients receiving tirofiban, and the chance of a heart attack was 27% higher. Cannon, however, cautioned that Topol's team may have used too low a dose of tirofiban. Studies are now being conducted using a higher dose.
Both studies were funded by Merck & Co., which manufactures tirofiban.
Feeling Moody? Ginseng Might Not Help
Ginseng is highly touted as a mood elevator, but a new study shows it is no more effective than a placebo.
Dr. Bradley J. Cardinal and his colleagues at Oregon State University studied 83 healthy young adults whose mood and feelings were measured for an initial two-week period. They were then randomly divided into three groups. One group received a placebo, one received the recommended 200-milligrams per day dose of ginseng extract, and one received 400 milligrams per day. After eight weeks, the initial mood tests were repeated.
The team reported in the June issue of the Journal of the American Dietetic Assn. that, after treatment, no differences in mood were observed among the three groups. The results are similar to those of earlier, small studies, which also found no benefit from the herb.
Stomach Removal Used to Prevent Cancer
A young Canadian woman whose identical twin was dying of a rare, inherited form of stomach cancer had her stomach removed prophylactically to prevent contracting the illness herself, an international team has reported in the New England Journal of Medicine http://(www.nejm.org).
Natasha Benn's mother had died of the same illness, as had her grandmother, great-grandfather and great-aunt. The surgery was performed eight years ago and Benn, now 32 and a resident of Victoria, British Columbia, is cancer-free, according to a team headed by Dr. David G. Huntsman of the University of British Columbia.
Benn was the first to undergo the prophylactic removal of a stomach, but subsequently, Benn's older sister and three members of a family in Detroit underwent the surgery. In all four cases, examination of the stomach after surgery showed traces of early stage cancer.
Patients can survive removal of the stomach because the intestines will continue to digest food. Patients must simply eat smaller meals more frequently.
The cancer is caused by a mutation in a gene called E-cadherin, discovered in 1998--well after Benn's surgery. Researchers believe that the gene causes from 1% to 2% of cases of stomach cancer. But people with the mutant gene have an 80% risk of developing the disease.
Some Parents See Benefit of Autism Shots
Some parents of children with autism believe that their offspring have been helped by injections of a gastrointestinal hormone called secretin, but clinical trials published to date have failed to show a significant benefit. Now, results released June 19 by Repligen Corp., which produces secretin, suggest there are identifiable subgroups of autistic children for whom the treatment is helpful.
The double-blind trial evaluated 126 children, ages 3 to 6, with moderate to severe autism. Results for the entire group, released earlier, suggested that parents saw some improvement but that the improvement could not be verified by independent assessment of the children by psychologists. The Repligen team also looked at a variety of biochemical markers, according to company president Walter Herlihy. Eventually, they focused on two proteins, called calprotectin and chymotrypsin.
Calprotectin is a marker produced during gastrointestinal inflammation; chymotrypsin is an enzyme released by the pancreas during digestion of food. When the team focused only on the 51% of patients with normal levels of both proteins, they observed a significant response to the secretin injections.
In contrast, patients with abnormal levels of one or both of the proteins accounted for most of the "placebo responders" in the trial--subjects who improved even though they did not receive the test drug.
Researchers Identify Natural Stroke Preventers
Lutein, a yellow pigment found in dark green leafy vegetables and egg yolks, may help to prevent strokes by reducing thickening of carotid arteries in the neck, according to USC researchers.
Many strokes occur when fragments of plaque in the carotid arteries break off, traveling to the brain and blocking capillaries. Lutein may prevent such occurrences by reducing the buildup of plaque, according to Dr. James H. Dwyer of USC's Keck School of Medicine.
Dwyer and his colleagues studied 480 men and women, ages 40 to 60, in the Los Angeles Atherosclerosis Study. The thickness of carotid arteries and the level of lutein in the blood were measured at the beginning of the study and 18 months later. The team reported in the June 19 issue of Circulation: Journal of the American Heart Assn. http://(circ.ahajournals.org) that the subjects with the highest blood levels of lutein had the smallest thickening of carotid arteries over the 18 months. The study may help explain why diets rich in fruits and vegetables are associated with a reduced risk of heart disease.
Medical writer Thomas H. Maugh II can be reached at http://email@example.com.