Ischaemic strokes are triggered by blood clots that interrupt blood supply to the brain. Strokes can cause permanent damage to humans, including paralysis, speech difficulties and even death in some cases. Alteplase works by breaking down these blood clots, although unfortunately, the research team have found that the drug offers no obvious improvement in survival rates.
The team's findings were that for every thousand patients administered the drug within six hours of suffering a stroke, within eighteen months, 36 more patients will have a good degree of independence and less physical discomfort than if they had not taken alteplase. The researchers emphasise, however, that this figure is an average and that their findings suggest that the sooner the drug is administered the better, as more of those given alteplase within the first few hours after a stroke will see these benefits.
This international trial looked at patients from twelve different countries, and in the cases they focused on, half the patients had the alteplase treatment, whereas the other half did not. The trial gained funding from a number of different areas, including the UK and Australian governments, the UK Stroke Association, the Medical Research Council and the Health Foundation UK.
A possible downside of this treatment is that the drug does carry a risk of causing a potentially fatal bleed on the brain in the first week after treatment, as this was recorded for around 3 in 100 patients. The experts from the University of Edinburgh emphasise the need for patients to weigh up the risks and benefits of this treatment before making any decisions.
Over 150,000 strokes occur each year in the UK alone, and some 85% of these are caused by a blood clot in the brain. Experts comment that if the patient can get to hospital quickly - that is, within four and a half hours of the stroke - clot-busting treatments such as alteplase, which can greatly reduce brain damage and disability, may be appropriate for them.