We have read with great interest the recently published paper by Chu et al1 about the diagnostic performance of mean platelet volume (MPV) for patients with acute coronary syndrome. In this report, similar to the findings of Yilmaz et al,2 the authors have shown that MPV was an early and independent predictor of acute coronary syndrome in patients with chest pain who presented to the emergency department. In this report,2 the authors have demonstrated that in patients with acute coronary syndrome MPV was an independent predictor of having a non-ST elevation myocardial infarction.

In fact, platelets are quite heterogeneous blood elements, diverging in terms of size, density and reactivity.3 Platelet size has been shown to be related to platelet reactivity4 and, along with this finding, there is evidence that MPV is an important biological variable, and immature platelets have larger MPV with higher thrombotic potential.5 Acute coronary syndromes are characterised by the rupture of unstable plaque following a thrombotic process involving platelets. An increase in platelet aggregability was shown to be an independent risk factor for future coronary events.6 In the recent study by Pizzulli et al,7 although the platelet count was similar in patients with a normal coronary angiogram and those with atherosclerotic disease, MPV was found to be higher in patients with coronary atherosclerosis. However, in their recent study, Yilmaz et al2 also demonstrated that higher MPV was related to a greater risk of having ischaemic complications in patients with non-ST segment elevation acute coronary syndrome.

In conclusion, we suggest that MPV as a marker of platelet reactivity is a simple and cost-effective test that can be used for risk stratification and prediction of future coronary events in the emergency department in patients with acute ischaemic syndromes.