Higher Coated-Platelet Levels in Acute Stroke are Associated with Lower Cognitive Scores at Three Months Post Infarction.

ABSTRACT

BACKGROUND: Coated-platelets are a subset of highly procoagulant platelets observed after dual agonist stimulation with collagen and thrombin. Coated-platelet levels are increased in acute stroke compared to controls, and higher levels are associated with stroke recurrence. We examined whether coated-platelet levels measured at the time of the stroke correlate with cognitive scores at 3 months following the brain infarction. METHODS: Coated-platelets were assayed in consecutive patients with nonlacunar stroke. Cognitive screening was performed using the Mini-Mental State Examination (MMSE) at 3 months after discharge. Linear regression, with adjustment for individual covariates, was used to model the association between coated-platelet levels and MMSE scores. RESULTS: One hundred and twenty-eight patients with a mean MMSE score of 26 points (range 14-30, standard deviation [SD] 3.1) and mean coated-platelet levels of 40.9% (range 5.2-76.2, SD 13.3), completed cognitive screening. An inverse linear association was found between coated-platelet levels and MMSE score, with higher levels seen in patients with lower MMSE scores (r = -.34, R2 = .12, P < .0001). This association remained despite adjustment for potential confounding factors. In the final model, higher coated-platelet levels (coefficient -.078, 95% confidence interval [CI] -.12 to -.041, P < .0001), presence of hypertension (coefficient -2.42, 95% CI -3.90 to -.95, P = .0015), and anticoagulant use at discharge (coefficient -1.48, 95% CI -2.56 to -.39, P = .0079) were predictive of lower MMSE. CONCLUSIONS: These findings support a link between increased platelet procoagulant potential at the time of the stroke and development of cognitive impairment following cerebral infarction.