Some 80% of strokes are of ischaemic origin (blocked vessels). Around 12% of patients die within the three months following the stroke, and 20% remain in an institution or are highly dependent.  When a person shows symptoms of a stroke, it is advisable to get them to hospital as quickly as possible so they can be given the appropriate treatment.

Once the ischaemic origin of the stroke has been confirmed by a brain scan, intravenous alteplase thrombolysis should be considered, ideally within the first 3 hours, in patients who are not at risk of haemorrhage, especially intracranial. Thrombolysis clears the blocked artery by dissolving the blood clot (or thrombus). It has a favourable harm-benefit balance, even in patients over the age of 80, and averts neurological consequences resulting in dependence in 9% of patients. Between 3 and 4-and-a-half hours after stroke onset its harm-benefit balance is uncertain, and beyond that it is unfavourable.

Aspirin (given its antiplatelet properties) helps prevent around 10 deaths or severe after-effects in every 1000 patients treated for a period of 1 to 6 months. In the case of alteplase treatment, the administration of aspirin should be deferred by 24 hours. If the patient has a history of allergy to aspirin, clopidogrel is an alternative.

The harm-benefit balance of an anticoagulant treatment appears to be unfavourable, including in patients with a secondary stroke following an embolism of cardiac origin.

Low-molecular-weight heparins reduce the risk of pulmonary embolism in patients at risk, but have no effect on the overall mortality.

©Prescrire 1 November 2013

"Antithrombotic drugs and ischaemic stroke. Thrombolysis for some patients, aspirin in nearly all cases" Prescrire Int 2013; 22 (143): 270-271. (Pdf, subscribers only).