Ugghhhh, bulls&%t:
Bacterial Link to Heart Disease Not Supported by New Research
Bloomberg News
Mar 13 2000 4:47PM
Anaheim, California, March 13 (Bloomberg) -- Bacteria thought to be linked to artery clogging may not be the culprit, new research suggests.
The findings come as Pfizer Inc. studies the effectiveness of its antibiotic Zithromax to prevent heart disease by fighting bacteria.
Much of the research presented this week at the American College of Cardiology's annual meeting in Anaheim, California, one of the world's largest gatherings of heart specialists, didn't support the link between bacteria and heart disease. For years, researchers have studied whether the body's own defenses against a strain of bacteria called chlamydia pneumoniae contribute to the build-up of plaque in arteries.
``Although some studies didn't pan out, the concept is still worth exploring,' said Joseph Muhlestein, a doctor with LDS Hospital in Salt Lake City, Utah.
In the 1980s, doctors found a similar link between another kind of bacteria and ulcers. Antibiotics now are part of the standard therapy in ulcer treatment.
Some of the more definitive data may come later this year when Pfizer presents the results of a trial of use of its Zithromax in about 3,500 patients, an effort known as the Wizard study. The people enrolled in this trial already have had heart attacks. Data could be available by mid-2000, Pfizer said.
The National Institutes of Health also is conducting a study of Zithromax and the prevention of heart disease, using about 4,000 patients, Muhlestein said.
Zithromax
Zithromax already is one of Pfizer's fastest-growing products. Its 1999 sales rose 28 percent to $1.3 billion, partly because of the ease of administration. A course of the drug sometimes can be completed with one dose a day for five days, while older, less-expensive antibiotics can require more pills a day over a longer time.
Zithromax also appears to work more effectively than some older drugs, especially on what are considered tough bacteria, such as chlamydia pneumoniae.
Still, there are questions about whether this strain of bacteria is the right target. Researchers at the William Beaumont Hospital in Royal Oak, Michigan, looked at the blood samples of about 53 patients who had new clogging in arteries after a procedure, called angioplasty. They were checking to see if there was a connection between infection by chlamydia pneumoniae and new clogging.
Angioplasty
In angioplasty, doctors push a balloon-tipped catheter through an artery to the site of blockage, then inflate the balloon to push back the plaque clogging the artery. In about 75 percent of cases, doctors then insert a tiny mesh tube called a stent to keep the artery open.
Even so, many patients get new clogging at the same site. Researchers have wondered if this new clogging around stents stems in part from the body's response to the trauma of having a stent installed in an artery. Some doctors hold a theory that this may help reactivate infection.
In the William Beaumont study, researchers analyzed blood samples. They didn't find evidence of chlamydia pneumoniae infection in patients with new clogging after stents were installed, said Harish Chandra, a researcher on the study.
Another study at the cardiology meeting had examined the effect of giving about 1,000 patients an antibiotic, roxithromycin, after they received stents. The results didn't show a benefit for the antibiotic, said Franz-Josef Neumann, a researcher on the study.
Another tactic may be to study the effect of new painkillers, the so-called Cox-2 drugs, in reducing the inflammation linked to new clogging in patients with stents, said William O'Neill, director of cardiology at William Beaumont.
Merck & Co.'s Vioxx and Monsanto Co.'s Celebrex, both introduced last year, appear to reduce inflammation without irritating the stomach as older painkillers do. O'Neill said he is talking with Monsanto about studying its drug in connection with preventing new clogging in arteries.
DAK |
