The University of Iowa
The University of Iowa News Services Home News Releases UI in the News Subscribe to UI News Contact Us


University of Iowa Hospitals and Clinics
Iowa City IA 52242
(319) 356-8755

Release: Immediate

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 and Stroke.

"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 said.

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.