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Two Duke Studies Find Doctors Still not Using Drugs Shown to be Beneficial in Clinical Trials

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Duke Health News 919-660-1306

ORLANDO, Fla. Two different analyses by Duke University
Medical Center cardiologists have shown that while multi-center
clinical trials involving thousands of patients have clearly
demonstrated that certain drugs can improve the outcomes for
heart patients and save lives, the message is not being
uniformly heard by physicians.

During the past decade, large-scale randomized clinical
trials have shown the effectiveness of such agents as beta
blockers, ACE inhibitors and aspirin in reducing the number of
deaths due to heart disease. While one might assume that the
results of these trials would change the way physicians
practice, that is not always the case, the researchers say.

The Duke studies show, for example, that the acceptance
rates by doctors of different classes of new drugs varies
widely, and can vary from region to region across North
America. A preliminary analysis by the Duke researchers
determined that if every patient who was an appropriate
candidate for one of the proven therapies actually received the
therapy, more than 80,000 lives a year could be saved.

The results of the two Duke analyses were prepared for
presentation during the 50th annual scientific sessions of the
American College of Cardiology.

WIDE VARIABILITY IN USE OF PROVEN MEDICINE: THOSE WHO WOULD
BENEFIT MOST LESS LIKELY TO RECEIVE LATEST THERAPIES

After analyzing one of the most comprehensive and
representative registries of heart patients in the world, Duke
University researchers found that of five therapies proven
effective by clinical trials, the usage ranged from 57 percent
for ACE inhibitors to 93 percent for aspirin.

The researchers studied the care received by nearly 10,000
patients enrolled at 94 hospitals in 14 countries who are part
of the Global Registry of Acute Coronary Syndromes (GRACE) to
see how often the findings of new clinical trials are really
being put into practice. For each of the five therapies, they
looked at how many patients who were candidates for the therapy
actually received it.

There was a broad range in the usage of the therapies, which
shows that while we ve had some success in convincing
physicians to use them, there still exists a great opportunity
for improvement, said lead researcher Dr. Christopher Granger.
It is obvious that many people who could benefit from these
newest therapies still aren t getting them.

Specifically, the researchers found the following usage for
the five therapies for patients with severe coronary
syndromes:

-- Aspirin: 93 percent received aspirin while in the
hospital, and 89 percent were prescribed aspirin after
discharge. Aspirin, which can keep platelets from clumping
together and forming clots, has been a mainstay of heart care
for many years.

-- Beta blockers: 81 percent received beta blockers in the
hospital, 71 percent at discharge. This class of drugs protects
the heart by keeping it from overreacting to stress
hormones.

-- ACE inhibitors: 64 percent received this drug in the
hospital, 57 percent at discharge. ACE inhibitors dilate blood
vessels and act similarly to beta blockers.

-- Reperfusion therapy: Seventy percent of patients who
could have received angioplasty or thrombolytic therapy
(so-called clotbusting agents) actually received the
therapy.

-- Low-molecular weight heparin or intravenous GP IIb/IIIa
inhibitors: Only 58 percent of patients who could have
benefited from this newest class of drugs actually received the
therapy. These drugs work similarly to aspirin by preventing
blood from clotting.

Certain drugs, such as aspirin, have higher use, perhaps
related to public awareness of their benefits, Granger said.
The other surprising and paradoxical finding is that those
patients who are at the highest risk -- and therefore those who
have the most to gain -- are less likely to receive proven
therapies.

Also, the researchers found that in the case of aspirin,
beta blockers and ACE inhibitors, patients were much more
likely to receive proven therapy if their doctor was a
cardiologist, Granger said.

For these reasons, Granger advocates developing a system
whereby doctors and patients would have to consult a checklist
before hospitalization or at discharge to ensure that the
latest therapies were considered for that particular patient.
Electronic systems for guiding and tracking, which have been
used less in medicine than other industries for quality
assurance, have been shown to improve use of effective
therapies, he said.

The analysis was supported by the Duke Clinical Research
Institute.

REGIONAL VARIATIONS IN THE USE OF HEART DRUGS

While the use of different therapies to treat or prevent
heart attacks varies widely across the United States and
Canada, Duke researchers found that regions with the highest
use of percutaneous coronary interventions had the lowest rates
of evidence-based medications.

The Duke researchers wanted to see how the different regions
of the country used the following proven therapies -- aspirin,
beta blockers, ACE inhibitors and percutaneous coronary
interventions, such as angiography and angioplasty -- for
improving survival of heart patients.

Unlike the other therapies, aspirin was used uniformly in
more than 95 percent of the patients across the regions.

The researchers, led by DCRI cardiology fellow Dr. M.
Cecilia Bahit, studied the data collected during ASSENT II, an
international trial that enrolled 16,949 heart attack patients
between October 1997 and November

1998. Of that group of patients, 4,806 (28 percent) were
treated in the U.S. and Canada.

In the ASSENT II trial, 87 percent of the eligible patients
who would benefit from beta blockers actually received the
drug, Bahit said. That is up from 72 percent from another large
trial (GUSTO-I) in the early 1990s, but it stills shows we have
room for improvement.

Some of the regional characteristics include:

-- The West-Central United States had the highest rate of
percutaneous interventions (53 percent) while New England had
the lowest rate (36 percent).

-- The Mid-Atlantic region and New England used beta
blockers 92 percent of the time, while the West-Central region
had the lowest (82 percent).

-- ACE inhibitors were least used in the East-Central U.S.
(42 percent) and most used in the Mid-Atlantic region (51
percent).

-- Canada, which has a different health care system than the
U.S., used percutaneous coronary interventions far less
frequently (13 percent) and had higher use rates of beta
blockers (85 percent) and ACE inhibitors (52 percent).

This is a snapshot of how these therapies are used in North
America, Bahit said. We do not know why there is a such a
disparity between regions of the U.S., especially since the
health care system is much the same. If we could better
understand these regional differences, we could be able to
improve the care for our patients.

The bottom line is that while we are getting better, we can
still save many more lives if more doctors put into practice
what we learn from these clinical trials, she said.

The analysis was supported by the Duke Clinical Research
Institute.

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