Coated-platelet levels are elevated in patients with transient ischemic attack.

Transient ischemic attack (TIA) presents a medical management dilemma because of the high frequency of subsequent ischemic strokes. The ABCD2 score is designed to stratify the short-term risk for stroke in TIA patients. Coated-platelets, which are a subset of procoagulant platelets observed after dual agonist stimulation with collagen and thrombin, are increased in cortical ischemic stroke and decreased in spontaneous intracerebral hemorrhage. Because TIA increases the risk of subsequent ischemic stroke, we conducted a pilot study to investigate whether coated-platelet production is increased in patients with TIA (n = 60) compared with controls (n = 60). Coated-platelet levels were higher in TIA patients versus controls [mean ± standard deviation (SD), 38.4 ± 15.1% vs 31.0 ± 13.2%, P = 0.005], and a significant linear correlation was detected between ABCD2 scores and coated-platelet levels in TIA patients (P = 0.0003, r = 0.45). These findings lend support to the hypothesis that TIA and ischemic stroke represent a spectrum of conditions dependent on similar prothrombotic processes.