When someone has a stroke, every minute counts. This is because the damage to the brain from oxygen deprivation is progressive. Most often, a stroke is caused by the presence of a clot in an artery serving the brain. Dissolving the clot, with a clotbusting drug like alteplase, can restore blood and oxygen supply and so limit brain damage and the resulting disability.

A study from a multinational group of researchers looks at some new data on how time elapsing between onset of stroke symptoms and treatment with alteplase affects the outcome. The number of patients covered is now 3670 and we have data on how alteplase compares with placebo. Generally, alteplase is beneficial if given early. One in three patients benefits if the drug is given between one and three hours after stroke onset and one in six if treated between three and four and a half hours after stroke onset. But beyond four and a half hours the risks outweigh the benefits.

The findings support making new efforts to expedite the treatment of stroke with clotbusters. First, the public should we aware of the early warning signs – speech difficulty, blurred vision, loss of function in a limb – of stroke. There is also a need for the patient to go straight to a stroke center, where everything is ready set up for their treatment. The more patients that can be treated within that ‘golden hour’ to minimize brain damage, the better the outcomes in terms of improved survival and reduced disability.

Source:

Lees K et al Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials The Lancet May 15 2010; 375:1695-703