By Karen Hsu, The Boston Globe
BOSTON --Two weeks ago, Arthur Toelken spelled relief:
L-A-S-E-R. With two bypass surgeries and an angioplasty already
behind him, the 65-year-old still was suffering from crippling
chest pain several times every day. ``I couldn't even get the mail
without having an angina,'' Toelken said.
His doctor at Brigham and Women's Hospital, Dr. Lawrence Cohn,
used a laser to zap about 30 toothpick-size holes in his heart wall
to reduce his chest pain. The surgery took an hour and left Toelken
with a four-inch incision in his chest.
Toelken, of Westfield, Mass., said he felt relief in his chest
immediately and has yet to take one of his nitro pills since his
operation. ``I feel better every day,'' and hopes soon that he can
drive, fish and hunt.
Toelken is one of several thousand patients who have tried this
laser procedure, known as transmyocardial revascularization or TMR,
which is reported in two studies in this week's New England Journal
of Medicine. The competing lasers used in the studies were
manufactuered by PLC Medical Systems in Franklin, Mass., and by
Eclipse Surgical Technologies in Sunnyvale, Calif.
The year-long studies, performed at 30 US hospitals, offered
hope for the estimated 80,000 Americans whose heart disease is too
far along for bypass surgery or balloon angioplasty. Angina happens
when the oxygen-starved heart muscle receives less blood than it
needs.
The two studies, one headed by Dr. Howard Frazier of the the
Texas Heart Institute in Houston and the other by Dr. Keith Allen
of St. Vincent Hospital in Indianapolis, both found that about 75
percent of of the several hundred patients involved reported
dramatic relief in chest pain after the laser surgery.
In addition, twice as many TMR recipients remained out of the
hospital for heart-related problems as those who received
conventional treatment. But between 3 and 5 percent of the patients
who underwent the operation died soon afterward.
The theory for the procedure's success is that it improved blood
flow. But only the Frazier study actually found improved blood flow
in its patients. The Allen study did not, nor did a study on a
third company's laser that was published in the Sept. 11 issue of
the Lancet.
So why are patients seeing relief?
``We don't have a full appreciation of how it works yet,'' Allen
said. A couple possibilities include: the laser creates
microinjuries in the heart, stimulating angiogenesis, which is
growth of new blood vessels; or, the laser blasts destroy the pain
fibers, so patients simply don't feel the pain, Allen said.
Cohn, chief of cardiac surgery at the Brigham, said that under
the microscope, they have seen evidence of angiogenesis in pig
models with the laser technique.
But other researchers are puzzled that the Frazier study showed
that the patients who had improved blood flow weren't always the
patients who felt better after the operation, and vice versa.
In an accompanying editorial in the journal, Drs. Richard Lange
and David Hillis of the University of Texas Southwestern Medical
Center in Dallas warned the pain reduction could be imaginary.
``These patients have exhausted all other options, so they are
in a mindset for anything. And lasers are really `Star Wars' -like
and magical,'' Hillis said. But Cohn noted the benefits of the
laser for some patients lasted more than three years. By then, an
imaginary effect would have worn off, Cohn said.
Hillis and others also criticized the studies' procedure: there
was a large crossover of patients, allowing those who did not see
effectiveness from standard drug treatment to have the surgery
done, suggesting a bias that the TMR treatment was better.
Dr. Ronald Weintraub, a cardiothoracic surgeon at Beth Israel
Deaconess Medical Center and member of the FDA panel that approved
the laser technique, said that although the editorial pointed to
valid problems with the studies, he also felt that ``they are
pretty good studies, and I'm not sure if better ones will be
done,'' Weintraub said.
``There is no question this is a new therapy, and it makes us
all uneasy because we don't understand how it works,'' said Dr.
Timothy J. Gardner, chief of cardiothoracic surgery at the
University of Pennsylvania and a spokesman for the American Heart
Association. ``But it does give us an option that we currently
don't have.''
