Timing of TIAs preceding stroke: time window for prevention is very short

Patients with TIA are at increased risk of ischemic stroke and require preventive treatment. However, clinical guidelines differ on how urgently patients should be assessed.

To determine the potential consequences of delays in investigation and treatment, the authors studied the timing of TIAs preceding ischemic stroke.

The authors studied patients who presented with a recent ischemic stroke and had a preceding TIA in two population-based studies (Oxford Vascular Study [OXVASC]; Oxfordshire Community Stroke Project [OCSP]) and two randomized trials (UK TIA Aspirin Trial [UK-TIA]; European Carotid Surgery Trial [ECST]).

Of 2,416 patients who had presented with an ischemic stroke, 549 (23%) gave a history of a preceding TIA (18% in OXVASC, 15% in OCSP, 23% in UK-TIA, 26% in ECST). Where a preceding TIA had occurred, the timing was highly consistent across the studies, with 17% occurring on the day of the stroke, 9% on the previous day, and 43% at some point during the 7 days prior to the stroke. No clinical characteristics or vascular risk factors identified patients in whom there was a close temporal association between TIA and stroke.

In patients presenting with ischemic stroke, TIAs occur most often during the hours and days immediately preceding the stroke.