Time Course of Platelet Activation and von Willebrand Factor in Patients With Non-Valvular Atrial Fibrillation After Ischemic Stroke

Evaluation of Prognostic Determinants

Abstract

Background The present study investigated serial changes in platelet activation (expressed by CD62p) and von Willebrand factor (VWF), and the correlation between increased CD62p expression, VWF and brain infarct volume (BIV: measured by magnetic resonance imaging), and prognostic determinants in non-valvular atrial fibrillation (NVAF) patients after acute ischemic stroke (IS). Methods and Results CD62p expression and plasma VWF concentrations were serially measured (<48 h, on days 7, 21 and 90) using flow cytometry and enzyme-linked immunosorbent assay, respectively after acute IS in 61 NVAF patients. CD62p expression and VWF concentrations were also examined in 50 NVAF-risk control and 30 healthy individuals. The VWF concentration had no significant changes at 4 intervals among the patients and did not differ among 3 groups at acute stroke phase. CD62p expression was significantly higher in the acute phase after IS than in both control groups (both p<0.0001). However, CD62p expression declined to a significantly lower level on day 7 and to a substantially lower level thereafter (p<0.0001). CD62p expression did not differ on day 90 in the 3 groups (both p>0.5). Linear regression analysis showed that BIV and modified Rankin scale score (>3) were independently associated with increased CD62p expression (<48 h) (both p<0.01). Furthermore, the Cox proportional hazards model showed that BIV was the only independent predictor of intermediate-term (8.8±4.4 months) combined recurrent stroke and death. Conclusions The CD62p expression, which reflected increased BIV, was significantly increased in NVAF patients in acute-phase IS and substantially declined thereafter. The BIV was predictive of unfavorable intermediate-term clinical outcomes. (Circ J 2007; 71: 321 - 326)