Doctors debate heart drill treatment for chest pain

In transmyocardial laser revascularization, or TMR, a laser creates up to 50 holes in a beating heart to relieve chest pain

September 30, 1999
Web posted at: 3:01 p.m. (1901 GMT)

From Medical Correspondent Rhonda Rowland

BOSTON (CNN) -- Two newly published studies indicate that a laser drill treatment for heart patients appears to relieve chest pain, but some cardiologists are questioning whether the surgery's benefits are merely an illusion.

The technique, transmyocardial laser revascularization (TMR), became available earlier this year for heart patients whose severe chest pain does not respond to traditional surgery or medication. Surgeons drill 10 to 50 holes in the heart with one of two lasers developed for TMR.

	VIDEO
CNN's Rhonda Rowland reports on the new procedure to bring relief for some angina patients. Windows Media 28K 80K

One of the studies, published Thursday in the New England Journal of Medicine, found 72 percent of the laser surgery patients had significantly less chest pain one year after the procedure, while only 13 percent of a comparison group using medication improved.

In addition, blood flow improved 20 percent in the TMR patients and worsened 27 percent in the medicine group.

"That's quite dramatic, clinically," commented Dr. Robert March of Rush-Presbyterian-St. Luke's Medical Center. March told CNN the drill treatment meant, "a patient may go from a bedridden state to being able to tolerate, easily, moderate activity."

The surgery's positive results were questioned, however, in an unusually negative editorial, published along with the studies in the journal.

Are impressive results imaginary?

"These apparently impressive results must be viewed with caution," wrote Dr. Richard Lange and Dr. L. David Hillis, both of University of Texas Southwestern Medical Center. They listed several reasons why the surgery patients' improvement could be mind over matter -- a placebo effect.

For instance, the patients who received the new, experimental surgery may have expected to feel better.

And the doctors running the study were also the ones to assess the patients' conditions after surgery. These "presumably enthusiastic" physicians may have looked harder for any benefit from the laser treatment.

But the director of one study, Dr. Keith Allen of St. Vincent Hospital in Indianapolis countered, "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." He added that the benefits lasted more than a year, and by then, any imaginary improvement would have disappeared.

Still unknown: How drill alleviates chest pain

Even the surgeons who perform TMR admit no one knows exactly how putting holes in the heart can relieve chest pain. One theory is that new blood vessels grow around the injured tissue; another is that some nerves are destroyed, so patients feel less pain.

Dr. Douglas Murphy of St. Joseph's Hospital in Atlanta suggested further research to identify how TMR works and which patients would benefit most.

"I think what we need to do is find which subgroup of patients get better and apply the laser TMR to those patients," he said.

The Associated Press contributed to this report.