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Study Reversal: Direct Angioplasty Isn't Better Than Clot-Busting Drugs for Treating Heart Attacks

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Duke Health News 919-660-1306

ORLANDO, FL – Contradicting earlier research, a Duke
University Medical Center study of patients from 57 hospitals
indicates that treating a heart attack by unclogging it with a
balloon catheter fails in the long run to save substantially
more people than therapy with clot-busting drugs. Not only does
the study, the largest of its kind, counter other findings that
the catheter method known as direct or primary angioplasty
saves significantly more lives, but it changes interpretation
of the initial results of the Duke study of 1,138 patients that
concluded direct angioplasty patients had a "small-to-moderate"
clinical advantage over thrombolytic drug therapy one month
after treatment.

Those same patients have now been followed for six months,
and the researchers found that advantage has diminished. The
rate of death or second heart attack was not statistically
different between the two therapies. The new findings were
prepared for presentation at the American Heart Association's
annual scientific meeting.

While the new study shows a clearer picture of the benefits
of the treatments, "we still don't have enough information to
definitively say which is better," said Duke cardiologist Dr.
Christopher Granger. "Although the truth is not clearly defined
yet, it's important to temper enthusiasm for expansion of
direct angioplasty into community hospitals."

Many hospitals have not waited for such long-term studies
before leaping into direct angioplasty, Granger said.
Introduced into general use only about three years ago, now 15
percent of all patients with heart attacks are treated with
direct angioplasty.

And this is worrisome, Granger said. "The patients in the
study were treated at centers that are very experienced in
angioplasty and yet there was, ultimately, no substantial
advantage in the treatment," he said. "We are concerned that
inexperienced hospitals are rushing to set up direct
angioplasty services, forsaking faster, efficient drug therapy
to offer perhaps less than optimal intervention.

"Direct angioplasty has excellent results in a place that is
extremely experienced with the technique, that can get heart
attack victims to the cath lab immediately and into the hands
of a skilled operator," he said. "But there are few hospitals
like that."

The finding is sure to intensify the already vigorous debate
about the benefit of direct angioplasty, a procedure that a
growing number of cardiologists love to do, Granger said in an
interview. "There seems to be no middle ground in this issue.
Most people are on one side or the other – direct angioplasty
or thrombolytic drug therapy."

Direct angioplasty is very satisfying to an interventional
cardiologist, Granger said. A patient comes in to the emergency
department complaining of chest pain. He is having a heart
attack. He's rushed to a "cath lab" where a physician threads a
catheter into the dying heart, inflates a balloon, and watches
on a monitor as the clog producing the attack is eliminated,
and blood rushes in. The patient feels better right away – and
the doctor sees the benefit of his work.

Moreover, by working directly in the heart, physicians can
tailor follow-up treatment. The procedure is financially
rewarding as well, Granger says.

Contrast that with its decidedly duller cousin, thrombolytic
therapy -- the intravenous infusion of clot-busting drugs such
as streptokinase and t-PA to relieve heart attacks. Neither the
doctor nor the patient knows if, and when, such drug therapy is
working. However, intravenous thrombolytic therapy is the
standard of care for patients having heart attacks, because of
its widespread availability and proven ability to reduce death.
More than a million people have received these drugs in the
past decade, Granger said.

Direct angioplasty became attractive in 1993 when three
small randomized trials concluded the technique saved an
estimated 40 lives per 1,000 patients treated, a huge clinical
advantage. But these trials were performed at "selected
hospitals with a lot of experience, involved few patients, and
except in one case, used thrombolytic regimens that are
suboptimal by today's standards," Granger said.

The Duke study was designed to study as many patients as
possible for a lengthier period of time. It looked at the
outcomes of 1,138 heart attack patients who were given either
the clot-busting drug t-PA or direct angioplasty in 57
hospitals in nine countries as part of a sub-study of the GUSTO
IIb (Global Use of Strategies to Open Occluded Coronary
Arteries in Acute Coronary Syndromes) clinical trial. Each
participating hospital had to be proficient in the procedure:
85 percent of the hospitals did at least 400 angioplasties
yearly.

The researchers looked at the outcome in patients 30 days
after treatment and found that direct angioplasty provided a
small-to-moderate, short-term clinical advantage. Death
occurred in 5.7 percent of the angioplasty patients, compared
to 7 percent in patients who received t-PA. Also, 4.5 percent
of angioplasty group experienced a second heart attack,
compared to 6.5 percent of drug therapy patients. That study
was published in the June 5, 1997 issue of The New England
Journal of Medicine.

But in the six-month follow-up, they found that the
advantage angioplasty patients had after one month diminished
six months later. The new results show no statistically
significant difference between the two groups. They
specifically found that:

7.8 percent of patients given angioplasty died, compared to
8.4 percent receiving drug therapy.

6.7 percent of angioplasty patients had a second heart
attack compared to 7.8 percent in the drug therapy group.

Death and/or second heart attack together affected 13.3
percent of angioplasty patients compared to 14.8 percent of
those treated with drug therapy.

Death, second heart attack or disabling stroke incident,
added together, affected 13.3 percent of angioplasty patients
compared to 15.7 percent of drug therapy patients. Pointing out
that none of the angioplasty patients had a stroke, Granger
said, "A major advantage of direct angioplasty is the low
incidence of strokes."

It took an average of two hours to treat patients with
direct angioplasty, versus 50 minutes for drug therapy. Time
matters when the goal is to save heart muscle, Granger said.
"One of the problems with direct angioplasty is that you have
to have a ready staff to do the procedure. Not many hospitals
are staffed like that." He also said that the time it took to
administer thrombolytics was too slow, as well.

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