More should receive clot-busting stroke drug: research

Graphic showing a the effects of a stroke on the brain

Many more stroke victims could be saved from disability because clot-busting drugs can be used for longer than previously thought, scientists say. 

At the moment there is a four-and-a-half hour window after stroke for administering the drugs, known as thrombolysis. It was recently increased from three hours.

However, Edinburgh University researchers have found that the most widely used clot-busting drug, rt-PA, is effective up to six hours after a stroke caused by a bloot clot in the brain, or 'ischaemic' stroke.

Ischaemic strokes starve a part of the brain of oxygen, causing disability or death. Every year about 150,000 people in Britain have a stroke, of which two-thirds have an ischaemic stroke. About 500,000 are thought to be living with disabilities such as partial paralysis caused by one.

In a study of more than 3,000 patients, they also found the drug could safely be used on those over 80. At the moment it is usually restricted to those under 80.

Previous research has found that for every 1,000 patients given the intravenous drug within three hours of stroke, 80 more will survive and be able to live independently. than if they had not received it.

Thrombolysis does slightly increase the chance of having a potentially deadly 'brain-bleed' stroke within a week, but many patients are happy to take the risk to avoid being disabled.

The results of this latest study are published in The Lancet.
Over the last five years there has been a big push to increase the proportion of ischaemic stroke patients who received clot-busting drugs.

The proportion has increased from one per cent in 2008 to eight per cent last year. These figures are not quite as low as may first appear: experts say only about 20 per cent of patients are clinically suitable, regardless of how long after stroke they present.

However, this finding may change that, as it suggests rt-PA can be used safely in more over 80s.

Richard Lindley, professor of geriatric medicine from Sydney Medical School, who co-authored the Lancet study, said: “Please don’t ignore the over 80s – they benefit hugely."

Dr Clare Walton, of the Stroke Association, described the research as "encouraging".

She said: "The results suggest that thrombolysis has the potential to be made available to many more patients. However, the treatment does carry risks and unfortunately not all stroke patients are eligible to receive it."