Laser can offer relief for severe chest pain

NEW ORLEANS _ A laser mounted on a tube the width of a cocktail straw can blast tiny holes in the walls of the heart, triggering the growth of blood vessels that substantially relieve crippling chest pain.

Lasers are already used as a last-ditch treatment of bad chest pain in some people, but an experimental new approach described Sunday appears much safer and can be used without open-heart surgery.

Experts say the promising results should help relieve many doctors' skepticism about laser therapy of the heart.

Heart lasers were approved by the U.S. Food and Drug Administration for routine use last year. However, the treatment requires opening the chest and carries a 6 percent to 10 percent risk of death.

The new approach involves threading the laser into the heart on a catheter, something that doctors do routinely for a variety of procedures, such as angioplasty.

If it works as well as data so far suggest, it could offer relief to many thousands of Americans whose heart pain cannot be treated with angioplasty or bypass surgery.

"This is for people with no options who are miserable with their angina," said Dr. Stephen N. Oesterle of Massachusetts General Hospital in Boston.

Oesterly presented the results of the largest study yet with this approach at a meeting of the American College of Cardiology.

In his study, doctors at 12 hospitals in the United States and England randomly assigned 221 patients to have either the laser therapy or routine medical care. All had severe angina, resulting from poor circulation to their heart muscle.

Angina is rated on a scale of 1 to 4. Before treatment, all were in stage 3 or 4, meaning they had chest pain will eating, brushing their teeth or even sitting perfectly still.

After laser treatment, two-thirds had improved at least two grades to stage 1 or 2. This meant they could walk about their homes comfortably, even though climbing stairs might still trigger pain.

"You can lead a normal life with class 2 angina," said Oesterle. "You cannot with class 4 angina."

The laser is threaded into the left ventricle, where doctors burn 10 to 15 tiny holes into the heart walls. None died during the procedure. Patients can be sent home the same day they are treated.

When the approach was first proposed in the 1980s, doctors theorized that the holes acted as substitute blood vessels, carrying blood to oxygen-starved muscle. However, experts now know that the holes themselves quickly plug up, serving no purpose.

Instead, it now appears that the laser damage somehow triggers the heart to grow tiny new arteries, a process called angiogenesis. These arteries feed the muscle that cannot be adequately nourished by the heart's clogged coronary arteries.

Dr. Ben McCallister of Mid America Heart Institute in Kansas City said Oesterle's results will probably make physicians more open to the idea of using lasers to improve heart circulation.

"There has been a lot of skepticism about this," said McCallister. "I think this very careful study will change the tide about how people think about this."

Oesterle tested a laser system developed by CardioGenesis Corp., where he has been a consultant. Similar approaches are also being tested with lasers developed by Eclipse Surgical Technologies and Biosense, Inc.

Dr. Patrick L. Whitlow of the Cleveland Clinic Foundation presented preliminary data at the meeting on patients treated with the Eclipse laser. Eighty percent of the patients improved at least two stages in their degree of angina.