Laser Heart Therapy Benefits Are Questioned
Newly approved laser drills appear to relieve heart patients' chest pain, but a medical journal critique questions whether the benefits are an illusion.
The technique, called transmyocardial laser revascularization, became available in large medical centers earlier this year as the latest approach to treating excruciating chest pain caused by bad hearts. The Food and Drug Administration approved heart lasers developed by PLC Medical Systems of Franklin, Mass., and Eclipse Surgical Technologies of Sunnyvale, Calif.
The approval was based on data from two large studies that are being published in today's issue of the New England Journal of Medicine. The journal carries an unusually negative editorial about the studies and the laser technology.
The technique uses a laser to drill 10 to 50 holes in the heart. The two studies, using the competing laser instruments, found that three-quarters of severely impaired patients improve significantly after the treatment.
However, the editorial--written by two cardiologists from the University of Texas Southwestern Medical Center in Dallas--raises the possibility that the benefits were imaginary, or a placebo effect, as physicians call it.
Blood Pressure Drug As Male Contraceptive
A drug currently used to treat high blood pressure appears to show promise as a male contraceptive, researchers reported.
New York researchers said they found that the drug widely used to control high blood pressure can also knock out the ability of sperm to penetrate an egg.
Susan Benoff of the New York University School of Medicine stumbled upon the idea for a male contraceptive when many of her male infertility patients with normal sperm counts were unable to fertilize eggs. Many of the men had high blood pressure and were taking a class of drugs known as calcium channel blockers, such as Procardia by Pfizer or Cardizem by Hoechst Marion Roussel. When the men switched to other anti-hypertensives, their fertility returned.
Benoff showed that the high blood pressure drug, called nifedipine, inhibits the movement of cholesterol in the sperm membrane, interfering with the mechanism that allows sperm to bind to an egg. She found that the drug worked as a contraceptive even at levels 10 to 100 times lower than what is typically prescribed for high blood pressure. It does not affect the blood pressure of patients who do not have hypertension. The contraceptive effect wore off within three months when men stopped taking the pill, Benoff said.
When present, side effects--headaches or gum bleeding--are minimal and far less, Benoff said, than side effects associated with oral contraception for women.
But don't expect to find the pills in a local drugstore soon. Benoff has approached six pharmaceutical companies to fund larger clinical trials of nifedipine or its derivatives. Each turned her down.