CONTACT: DR. HAROLD ADAMS
University of Iowa Hospitals and Clinics
Iowa City IA 52242
EMBARGOED: For release 3 p.m. CST Tuesday, April 21, 1998
Stroke patients don't experience benefit from common drug therapy
IOWA CITY, Iowa -- A national study coordinated by stroke specialists
at the University of Iowa concludes that patients with acute stroke do
not experience long-term benefit from a commonly administered drug therapy.
The seven-year study, published in today's edition of the Journal of
the American Medical Association, resolves long-standing questions about
the benefits of antithrombotic drugs administered immediately after a patient
has a stroke (emergent anticoagulant therapy). Emergent anticoagulants
include heparin and low molecular weight heparin.
Many doctors believed that some stroke patients appeared to benefit
from emergent antithrombotic therapy. However, scientific evidence to validate
its safety and effectiveness did not exist. This prompted University of
Iowa neurologist Harold Adams and a team of UI colleagues to coordinate
the study, sponsored by the National Institute of Neurological Disorders
"Unfortunately, emergent anticoagulant therapy does not improve
patient outcomes," said Adams, senior principal investigator of the
study. "We can say with certainty that except for a small subgroup
of patients, there is no long-term benefit."
Adams noted that the study did not address the use of heparin in non-emergency
circumstances. "Heparin therapy might well have an important ancillary
role in the overall treatment of stroke by preventing the complications
of blood clots in the leg-more-or lung," he said. "Those questions
will need to be answered in another study."
In all, 36 health care centers nationwide participated in the study,
nicknamed TOAST (Trial of Org 10172 in Acute Stroke Treatment). An independent
group of physicians at the University of Iowa monitored the safety aspects
of the study.
The 1,281 patients who enrolled in TOAST received either emergent anticoagulant
therapy or a placebo for one week following acute stroke. Researchers evaluated
patient progress for some three months after treatment.
"Our study suggests that the use of drugs such as heparin increases
the risk of brain hemorrhage, particularly among patients with severe stroke,"
Adams said. "Clearly, doctors should avoid administering the drug
under these circumstances."
Researchers also wanted to know if anticoagulant treatment prevents
recurrent stroke. "In fact, our study suggests it does not, largely
because the overall risk of early recurrent stroke is low," Adams
Actually, researchers found that despite increased bleeding from emergent
anticoagulant therapy, many patients being treated with the medication
improved after one week. By three months, however, patients who received
drug therapy and those who didn't were doing equally well. The drug had
no long-term treatment effects.
Nevertheless, a subgroup of patients seemed to benefit from anticoagulant
therapy. Patients with stroke resulting from disease of the large vessels
in the brain (carotid artery disease) or large artery atherosclerosis appeared
to benefit both after one week and again at three months.
However, the study concludes that for this treatment to be effective,
early and accurate determination of this type of patient requires the use
of special tests such as duplex ultrasound of the carotid artery, transcranial
Doppler, magnetic resonance angiography, or CT angiography. Accordingly,
the study encourages a follow-up prospective study evaluating such an approach.
"Despite the overall outcome, TOAST provides other information
that hopefully influences future care," Adams said. "This is
still an important step forward in our ongoing search for the safest and
most effective treatment of patients with acute ischemic stroke."
In addition to Adams, UI collaborators in the TOAST study included data
management director Dr. Robert Woolson and approximately 45 people from
the UI departments of neurology, preventive medicine, radiology, pediatrics,
pathology and pharmacy. In addition to the UIHC, Iowa Methodist Medical
Center in Des Moines participated in the study.