The relationship between mean platelet volume, stroke subtype and clinicaloutcome

Platelets play a crucial role in the pathophysiology of atherothrombotic di sease and are involved in the early thromboembolic phase of ischaemic strok e, Large platelets are known to be more active. We hypothesized that thromb omegaly would be limited to patients with cortical infarction as compared w ith patients with lacunar infarcts, and that it would be associated with fu nctional outcome. Mean platelet volume (MPV) and platelet count (PC) were s tudied in 167 hospitalized patients with stroke within 48 h of symptom onse t, and 65 age, gender and race matched controls. Stroke was clinically and radiologically sub-typed. MPV was significantly higher in patients with isc haemic stroke than the control group: mean (SD) 7.35 (1.05) vs 7.09 (0.74) fl, 2P = 0.04; this difference could be explained by MPV being higher in pa tients with cortical stroke: 7.46 (1.00) fl, 2P = 0.039, but not lacunar in farction: 7.14 (1.16) fl, 2P = 1.0, No difference was seen in PC between is chaemic patients and controls: 231 (82) 10(9)/l vs 236 (54) 10(9)/l, 2P = 0 .63, MPV did not change at 3 months post-stroke in surviving patients with ischaemic stroke: 7.39 (1.03) fl vs 7.34 (0.97) fl, 2P = 0.53. Patients who were dead or dependent at 3 months had a significantly higher baseline MPV and a tendency to a lower PC than those who returned to independence. MPV and PC were not altered in patients with primary intracerebral haemorrhage. No differences in red cell volume was observed. Platelet volume is elevate d in acute ischaemic stroke, a finding that persists at 3 months post-strok e and is limited to patients with cortical infarction, Thrombomegaly is a r isk factor for a poor outcome after ischaemic stroke.