Health Highlights: Aug. 31, 2004
ACE Inhibitors Protect Artery Lining FDA Approves First Stroke-Preventing Stent HIV Patients Can Carry Different Forms of Virus Cholesterol Drug Causes Muscle Weakening in Higher Doses: Study Heart Attacks More Likely During Cold Weather Study Questions Value of Stroke Prevention Surgery
Here are some of the latest health and medical news developments, compiled by editors of HealthDay:
ACE Inhibitors Protect Artery Lining
Blood pressure drugs called ACE inhibitors not only lower blood pressure but also improve the health of artery walls, says an Italian study that reveals exactly how the drugs help protect people against heart attacks.
It's long been suspected that there had to be something else besides the ability of ACE (angiotensin converting enzyme) inhibitors to lower blood pressure to explain their benefit to patients.
Previous research found that ACE inhibitors prevented heart attacks and deaths even in people with normal blood pressure and in patients who still had high blood pressure, the Associated Press reported.
This study found that ACE inhibitors also preserve the delicate lining of blood vessel walls. This lining helps repel plaque, which can cause heart attacks if it builds up in arteries.
The findings were presented at the European Society of Cardiology meeting in Munich, Germany.
FDA Approves First Stroke-Preventing Stent
A stent designed to prevent stroke by opening blockages in the carotid artery in the neck has won approval from the U.S. Food and Drug Administration.
This device is the first of its kind. The FDA approved its use in patients who've had stroke symptoms or whose carotid artery is at least 80 percent blocked, and who aren't good candidates for surgery.
The carotid artery is the main blood vessel leading to the brain.
"Carotid stents offer doctors a new, less-invasive option for clearing blocked neck arteries. This approval is another step forward in the prevention of stroke," Dr. Lester M. Crawford, acting FDA commissioner, said in a prepared statement.
The newly-approved stent, made by Guidant Corp. of Santa Clara, Calif., is inserted during angioplasty. The FDA approved the stent based on Guidant's clinical studies of 581 patients in 45 medical centers.
HIV Patients Can Carry Different Forms of Virus
People with HIV may carry more than one strain of the virus, meaning that even partners who are both HIV-positive should practice safe sex, say researchers in Montreal.
They published a case study of a man who initially contracted a drug- resistant form of HIV and then was re-infected 10 months later with another strain of HIV. The case study appears in the August issue of the journal AIDS.
"We used to say to couples who are both HIV-positive, you don't have to take precautions. Now I think we have to be a little bit more cautious," Dr. Mark Wainberg, director of the McGill AIDS Centre, told CBC News Online.
He and his colleagues estimated that 3 to 4 percent of newly infected HIV patients may have a secondary HIV infection, a situation referred to as superinfection.
Superinfections are now a regular occurrence in many countries, and will set back research and make it much more difficult to treat HIV/AIDS, Wainberg said.
Cholesterol Drug Causes Muscle Weakening in Higher Doses: Study
Higher doses of the cholesterol-lowering drug Zocor produced muscle-weakening problems in some people who had recently suffered a heart attack, according to a study to be published in the Journal of the American Medical Association.
Zocor is among a class of drugs called statins, which have been shown to lower users' risks of heart attack and stroke. But in the new study, sponsored by Zocor's manufacturer, adverse muscle reactions were reported among some users who took twice the common 40-milligram dose, The New York Times reported.
Researchers at the University of Texas Southwestern Medical Center in Dallas recruited 4,497 patients from 41 countries. One group took the normal 40-mg dose of the Merck drug, while a second group quickly upped the dose to 80 mg.
While the higher-dose patients appeared to fare slightly better over time, the difference between the two groups wasn't statistically significant, the newspaper reported from the study. And nine patients in the higher-dose group suffered from myopathy, a muscle-weakening disorder estimated to affect one in 1,000 statin users. None of the lower-dose patients was diagnosed with the problem.
The study was released Monday on the Journal of the American Medical Association's Web site after it was presented at a European Society of Cardiology conference in Munich, Germany. It will appear in the Sept. 15 issue of the journal.
Heart Attacks More Likely During Cold Weather
As the weather gets colder and a person's blood pressure rises, so does the risk of a heart attack, a new study finds.
Cold weather makes the blood vessels constrict, posing more of a danger to people with high blood pressure than the average person, French scientists at the University of Burgundy found.
Among 748 heart attack victims studied, attacks were more frequent when the temperature fell below 39.2 degrees, the Associated Press reported of the study's findings. And closer analysis revealed that this was true only for people who had high blood pressure, the study's authors found.
Heart attack risk among people with high blood pressure also rose when the temperature dropped by at least 10 degrees on the day of the heart attack, regardless of how cold it was, the AP reported.
The findings were presented Monday at a European Society of Cardiology conference in Munich, Germany.
Study Questions Value of Stroke Prevention Surgery
A common surgery to prevent stroke by scraping out an artery in the neck may not be necessary in many patients and may actually be harmful to some, Canadian researchers have found.
The procedure, called carotid endarterectomy (CE), was justified in only 52 percent of 3,200 cases studied, according to findings published in Tuesday's Canadian Medical Association Journal. Another 37 percent were found to be of uncertain benefit, and more than 10 percent of the surgeries actually put the patients at greater risk, according to a report in the Globe and Mail of Toronto.
CE is done to remove plaque from the main artery that supplies the brain with oxygen-rich blood. It's generally recommended for patients whose artery is at least 50 percent blocked, the newspaper reported.
But many of the patients whose cases were studied had the procedure when the artery was only slightly blocked, according to the Globe and Mail. Other studies have found the procedure offers dubious benefit under these circumstances, since as many as 5 percent of patients die of a stroke or other complications during a CE, the newspaper said.