By DANIEL Q. HANEY
September 29, 1999
BOSTON (AP) - 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 Thursday'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, both 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 doctors call it.
``These apparently impressive results must be viewed with caution,'' wrote Drs. Richard A. Lange, Southwestern's director of cardiac catheterization, and L. David Hillis, vice chairman of medicine.
In the studies, half the patients got laser treatment, while the rest received standard medicines. Among the Texas doctors' concerns:
-Patients knew they had gotten the laser, so their expectations of benefit may have made them believe their chest pain had eased.
-Doctors who performed the study assessed the patients' conditions. These ``presumably enthusiastic'' physicians may have been more likely to see benefit in those getting the laser.
-Patients in the group getting medicine alone were allowed to receive the laser if they failed to improve. This arrangement ``implies a bias on the part of the investigators'' that the laser treatment was better.
-No one can convincingly explain why the treatment works. One theory - that it creates new blood channels - has been discredited. Another is that it destroys nerves in the heart, so patients feel less pain.
In an interview, Lange said he thought the lasers should be used only in studies, not routinely on heart patients.
Dr. Keith B. Allen of St. Vincent Hospital in Indianapolis, who directed one of the studies, responded: ``I've heard it all before. All you have to do is interview patient after patient who had this procedure and see the effect and realize there is more than a placebo effect.''
Allen noted the benefits of the laser lasted more than a year. By then, a placebo effect would almost certainly have worn off.
