Abstract TP459: Higher Coated-Platelet Levels in Patients with Acute Stroke are Associated with Lower Cognitive Performance at 3 Months

Abstract

Introduction: Coated-platelets, a subset of procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin, support a robust prothrombinase activity and provide a unique measure of platelet thrombotic potential. Coated-platelet levels are increased in non-lacunar stroke compared to healthy controls, and higher levels are associated with stroke recurrence. In prior studies, we have shown that coated-platelet levels in patients with carotid atherosclerosis and cognitive impairment are elevated as compared to those with normal cognition. Hypothesis: To examine whether coated-platelet levels measured at the time of the stroke correlate with cognitive performance at 3 months following the brain infarction. Methods: Consecutive patients with a diagnosis of non-lacunar stroke were enrolled in this pilot study over 12 months. Coated-platelets were determined at the time of the stroke and reported as percent of platelets converted to coated-platelets. Cognitive screening was performed using the Mini-Mental State Examination (MMSE) during a stroke clinic visit 3 months after hospital discharge. Patients with prior dementia or significant aphasia were excluded. The linear correlation between initial coated-platelet levels and MMSE scores at 3 months was examined using the Pearson correlation coefficient. Results: We enrolled 66 patients, 97% male, with a mean age of 66.7 years (range 49-88) and mean NIHSS score of 4.4 points (range 0-11). Mean MMSE was 26.3 points (range 18-30) and mean coated-platelet levels were 41.4% (range 15.4-76.2). 34 patients (52%) had MMSE scores of ≤26, suggestive of a degree of cognitive impairment. An inverse relationship was found between coated-platelet levels and MMSE score, with higher levels seen in patients with lower MMSE scores (r=-0.45, R 2 =0.21, p=0.0001). This association remained despite adjustment for presence of large-artery disease and stroke severity. Conclusions: Higher initial coated-platelet levels are associated with lower cognitive performance at 3 months post stroke. These findings support a link between increased platelet procoagulant potential and development of vascular cognitive impairment following cerebral infarction.