Stroke After TIA: How Likely and How Soon?

Urgent intervention after transient ischemic attack (TIA) is highly effective for preventing recurrent stroke. Most guidelines recommend neurological evaluation within 24 hours after symptom onset, yet some patients with TIA have strokes within that 24-hour period. As part of a prospective study of all strokes and TIAs in a population of 91,106 individuals in Oxfordshire, U.K. (the Oxford Vascular Study), researchers assessed the risk for stroke within 24 hours after a first TIA and the predictive value of the ABCD² risk scoring system.

Among 488 patients with first TIAs from 2002 to 2007, the risk for stroke was 1.2% within 6 hours, 2.0% within 12 hours, and 5.1% within 24 hours. Of the 59 strokes that occurred within 30 days after TIA, 25 …