Study hints stroke drug could have wider use

By Julie Steenhuysen

CHICAGO (Reuters) - A study aiming to expand the three-hour time window for giving a clot-busting drug to stroke patients fell short of its goal, Australian researchers said on Friday, but the study hinted that certain stroke sufferers might still benefit from late administration of the drug.

They had hoped to prove the clot-buster known as tissue plasminogen activator or tPA would significantly reduce the spread of a stroke three to six hours after the first symptoms appeared.

Under current guidelines, the drug can only be given within three hours of the first symptoms, a restriction that leaves out all but a lucky few who get immediate help.

When given promptly, tPA can reduce permanent disability. It only works on ischemic stroke, which is caused when a blood clot chokes off blood flow to the brain.

Stephen Davis of Royal Melbourne Hospital in Victoria, Australia, wanted to see if the drug could help a subset of stroke patients with salvageable brain tissue after the three-hour time limit had passed.

He and colleagues studied 101 patients who received tPA or placebo three to six hours after their stroke started. Of these, 99 people or 86 percent were believed to have salvageable brain tissue. About half of these got tPA and half got placebo.

While the late use of the drug did not show statistically significant improvement, it did show a strong trend toward saving brain tissue, said Davis, whose study was published in the journal Lancet.

It also helped improve blood flow into the damaged area, a finding that was statistically significant.