Association of Immature Platelets with Adverse Cardiac and Cerebrovascular Outcomes

Backgrounds: Platelets play a pivotal role in the development of atherothrombotic events and platelet hyper-reactivity is associated with adverse prognosis in patients with acute coronary syndromes (ACS). Immature platelets (IPs) are newly-formed platelets with high dense granules content, a residual amount of mRNA and increased mean volume compared to older circulating platelets. Detection of these platelets in the circulating blood reflects a high rate of platelet turnover. Recently an increased proportion of IPs has been proposed to be independent predictor of cardiovascular death in patients with CAD.

Objective: To examine whether the level of IPs in patients with ACS predicts adverse cardiovascular events

Methods: We recruited patients with ACS. We measured the immature platelet fraction (IPF) using an automated hematoanalyzer, after anti-platelet drug loading and performance of percutaneous coronary intervention. Patients were followed for a period of 6 months. Major adverse cardiovascular events (MACE) were defined as the composite of all-cause mortality, non-fatal myocardial infarction, cerebrovascular event and hospitalizations due to cardiac causes.

Results: A total of 104 patients were recruited and had 6 months follow-up (mean age 67.2±13, 26% females, 41.3% STEMI, 58.6% NSTEMI-UAP). They were divided to quartiles and halfs based on their IPF level. MACE according to quartile significantly differed between the quartiles (p=0.015). MACE according to half increased from the lower IPF half to the upper half (23% and 46%, respectively, p=0.013). The differences in MACE between the IPF quartiles and halfs were driven by differences in the rates of hospitalizations due to cardiovascular causes. Mortality and re-infarction rates were low and did not differ between the different groups.

Conclusion: In this preliminary study of patients with ACS there appears to be an association between IPF level and cardiovascular outcomes at 6 months, driven by cardiac hospitalization rates. Further studies required to validate these findings.