Spontaneous Micro-Aggregation of Platelets Predicts Clinical Outcome in Acute Ischemic Stroke.

BACKGROUNDS: Spontaneous micro-aggregation of platelets (SMAP) is frequently observed in stroke patients and is a trigger for the additional development of larger thrombi. We tested the hypothesis that SMAP may predict clinical outcome in acute ischemic stroke patients. METHODS AND RESULTS: Consecutive acute ischemic stroke patients (n = 358) who were transferred to our hospital within 24 hours after its onset were enrolled. Peripheral venous blood was sampled to measure various parameters when they arrived. SMAP was correlated with plasma brain natriuretic peptide and diastolic blood pressure positively, and with serum albumin and body weight negatively. Multivariable Cox regression analysis showed that only serum albumin was an independent predictor of the SMAP (P = .0023). The proportion of patients who were functionally independent (score 0-2 on the modified Rankin Scales) at discharge was lower in the third tertile of SMAP (higher level) as compared with the first and the second tertiles in ischemic stroke (odds ratio [OR], 5.76; 95 % confidence interval [CI], 3.31-10.05; P < .0001) and atherothrombotic stroke (P = .02 by chi-square test). The lower proportion of patients achieving independence was found in the first tertile of serum albumin (lower level) as compared with the second and third tertiles in ischemic (OR, 4.60; 95% CI, 2.66-7.95; P < .0001), atherothrombotic, and cardioembolic stroke (P = .004 and P < .0001 by chi-square test). On logistic regression analysis, SMAP and serum albumin remained independent predictors of poor outcome in ischemic stroke. CONCLUSIONS: SMAP within 24 hours after stroke onset is a novel independent predictor of clinical outcome in acute ischemic stroke patients.