Serial changes of mean platelet volume in relation to Killip Class in patients with acute myocardial infarction and primary percutaneous coronary intervention.

Introduction: Mean platelet volume (MPV) is related to the reactivity of platelets. Among survivors of acute myocardial infarction (MI), greater MPV is known to be associated with impaired reperfusion and higher mortality. The aims of the study is to investigate the dynamic changes of MPV and the relation between MPV and cardiac function in patients with acute MI and received primary percutaneous coronary intervention (PCI).

Materials And Methods: This retrospective cohort study included patients presented during January 2008 to March 2011 to Peking University Third Hospital with ST-segment elevation MI. All patients received successful PCI. MPV was measured serially, using a Sysmex XE2100 haematology analyser, from admission to day-7 after MI.

Results: In 375 patients, MPV was at its highest value (10.2±1.0 fL) and correlated well with platelet distribution width (PDW, r=0.833, p<0.0001) at the admission, and then reduced by 16% within the 24 hours, together with marked weakening of its correlation with PDW. Patients with poorer ventricular function, estimated by high Killip Class (≥2, n=96), had higher MPV values at all-time points. By logistic regression model and after adjusting for related confounders, high MPV remained as an independent predictor of Killip Class ≥2 (OR 1.873, CI 95% 1.373-2.673, p=0.001). Clopidogrel pre-usage resulted in significant MPV reduction on admission.

Conclusions: MPV undergoes rapid and dynamic changes during the acute phase of MI, and was higher in patients with high Killip Class, suggesting a predictive value of MPV in ventricular dysfunction and clinical outcome of acute phase of MI.