Oral antiplatelet therapy for acute ischaemic stroke

Acute ischemic stroke is characterized by sudden loss of arterial blood supply to cerebral tissue, often precipitated by a thromboembolic event and associated platelet activation. The cornerstone of acute management involves administration of antiplatelet therapy to minimize risk of early recurrent ischemic stroke, thereby reducing morbidity and mortality. The described benefits of antiplatelets are weighed against the risk of fatal or disabling intracranial hemorrhage associated with their administration.

Objectives

The aim of this systematic review and meta-analysis was to assess the efficacy and safety of immediate oral antiplatelet therapy (ie, started as soon as possible and no later than 2 weeks after stroke onset) in people with acute presumed ischemic stroke.

Search Methods

We searched the Cochrane Stroke Group Trials Register, CENTRAL, MEDLINE Ovid, Embase Ovid, and 2 trials registers and performed forward reference/cited reference searching in August 2020.

Selection Criteria

Randomized controlled trials comparing oral antiplatelet therapy (started within 14 days of the stroke) with control (placebo or no treatment) in people with definite or presumed ischemic stroke.

Data Collection and Analysis

Two review authors independently applied the inclusion criteria and assessed trial quality. For the included trials, they extracted and cross-checked the data. They assessed risk of bias of each trial using the Risk of Bias 1 tool, heterogeneity between trial results using the I2 statistic, and overall certainty of the evidence for each outcome using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach.

Main Results

Fifteen thousand eighty-five citations were identified from electronic searches, and 16 full-texts were retrieved. We included 11 trials involving 42 226 participants. Two trials testing aspirin 160 to 300 mg once daily, started within 48 hours of onset, contributed 96% of the data. The risk of bias was low. The maximum follow-up was 6 months. With treatment, there was a decrease in death or dependency at the end of follow-up (odds ratio, 0.95 [95% CI, 0.91 to 0.99]; P=0.008, I2=0; 7 randomized controlled trials, 42 034 participants; moderate-certainty evidence; Figure). For every 1000 people treated with aspirin, 13 people would avoid death or dependency (number needed to treat for an additional beneficial outcome 79). Antiplatelet therapy was associated with a net reduction in the odds of any recurrent stroke/intracranial hemorrhage (odds ratio, 0.88 [95% CI, 0.79–0.97]; P=0.01, I2=23%).