Clot-buster drug safe for treating stroke, study says

By Patricia Reaney

LONDON (Reuters) - A clot-busting drug routinely given to heart attack patients is safe and effective for treating stroke and can reduce disability if it is given to patients quickly, scientists said on Friday.

The drug, alteplase, is produced by the California-based biotechnology company Genentech under the brand name Activase.

Scientists who tested it in stroke patients said it was most effective if patients were treated within three hours of suffering the stroke.

"If you give this treatment very quickly ... you can dissolve the blood clot and the blood circulation is restored to the area before the brain is injured," said Professor Nils Wahlgren, of the Karolinska University Hospital in Stockholm.

Although the drug has been given to heart attack patients, fears about the risk of brain hemorrhage have delayed its use in stroke sufferers.

But Wahlgren and his team, who tested alteplase on 6,483 stroke patients in Europe, said any limited risk is outweighed by the benefits of the treatment.

"Provided that it can be given within the three-hour time limit and in qualified stroke units, I think this should be the standard therapy for ischemic stroke patients: those with a blood clot in the brain," added Wahlgren, who reported in the findings in The Lancet medical journal on Friday.

He told Reuters that patients with symptoms of a stroke such as difficulty speaking, confusion, numbness, severe headache and dizziness should call emergency services immediately.

"People must react quickly," he stressed.

Strokes are caused by a blood clot or bleeding in or around the brain. About 17 million people die each year of cardiovascular diseases, particularly heart attacks and strokes. High blood pressure, diabetes, smoking, raised cholesterol, obesity and lack of exercise are risk factors.

In a separate study in the journal, scientists at the National Institutes of Health in Bethesda, Maryland said magnetic resonance imaging (MRI) is better than computed tomography or CT, which is commonly used to detect an acute stroke.

When they compared the effectiveness of the two imaging systems in detecting stroke in 356 patients treated in an emergency room for symptoms, MRI came out on top.

MRI had a sensitivity of 83 percent compared to 26 percent for CT for diagnosing acute stroke.

"Because MRI is more effective for detection of acute ischemia (stroke), and can detect acute and chronic hemorrhage, it should be the preferred test for accurate diagnosis of patients with suspect stroke," the researchers said in the study.