CAST: randomised placebo-controlled trial of early aspirin use in 20,000 patients with acute ischaemic stroke. CAST (Chinese Acute Stroke Trial) Collaborative Group.

There are two major trials of aspirin in acute ischaemic stroke. Taken together, CAST and the similarly large IST show reliably that aspirin started early in hospital produces a small but definite net benefit, with about 9 (SD 3) fewer deaths or non-fatal strokes per 1000 in the first few weeks (2p = 0.001), and with 13 (5) fewer dead or dependent per 1000 after some weeks or months of follow-up (2p < 0.01).