Antiplatelet therapy for acute ischaemic stroke.

BACKGROUND:

In patients with acute ischaemic stroke, platelets become activated. Antiplatelet therapy might reduce the volume of brain damaged by ischaemia and reduce the risk of early recurrent ischaemic stroke. This might reduce the risk of early death and improve long-term outcome in survivors. However, antiplatelet therapy might also increase the risk of fatal or disabling intracranial haemorrhage.

OBJECTIVES:

The aim of this review is to assess the net result of antiplatelet therapy in acute ischaemic stroke.

SEARCH STRATEGY:

We searched the Cochrane Stroke Group trials register (most recent date of search March 1999), the register of trials held by the Antiplatelet Trialists' Collaboration, and MedStrategy (1995). We also contacted relevant pharmaceutical companies.

SELECTION CRITERIA:

Randomised trials comparing antiplatelet therapy started within 14 days of the stroke with control in patients with definite or presumed ischaemic stroke.

DATA COLLECTION AND ANALYSIS:

Two reviewers independently applied the inclusion criteria and assessed trial quality, and for the included trials, extracted and cross-checked the data.

MAIN RESULTS:

Eight trials involving 41,325 patients were included. Two trials testing aspirin 160 to 300 mg once daily started within 48 hours of onset contributed 98% of the data. The maximum follow-up was six months. With treatment, there was a significant decrease in death or dependency at the end of follow-up (OR = 0.94; 95% CI 0.91 - 0.98). In absolute terms, 13 more patients were alive and independent at the end of follow-up for every 1000 patients treated. Furthermore, treatment increased the odds of making a complete recovery from the stroke (OR = 1.06; 95% CI 1.01 - 1.11). In absolute terms, 10 patients made a complete recovery for every 1000 patients treated. Antiplatelet therapy was associated with a small but definite excess of 2 symptomatic intracranial haemorrhages for every 1000 patients treated, but this was more than offset by a reduction of 7 recurrent ischaemic strokes for every 1000 patients treated.

REVIEWER'S CONCLUSIONS:

Antiplatelet therapy with aspirin 160 to 300 mg daily, given orally (or per rectum in patients who cannot swallow), and started within 48 hours of onset of presumed ischaemic stroke reduces the risk of early recurrent ischaemic stroke without a major risk of early haemorrhagic complications and improves long-term outcome.