الفهرس 
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Abstract
Despite the developments regarding its diagnosis and treatment in recent years, acute coronary syndrome (ACS); unstable angina, non ST elevation myocardial infarction and ST elevation myocardial infarction, keeps its place as the most important reason of morbidity and mortality. Cardiac diseases have been known to be the number one cause of death since the beginning of twentieth century.
ACS encompasses the diagnoses of unstable angina (UA) and MI. UA is an acute condition of myocardial ischemia without sufficient severity and duration to result in myocardial necrosis. Patients with UA do not release biomarkers of myocardial necrosis at detectable levels into the blood, and they do not typically present with ST elevation on the ECG. In acute MI, the severity and duration of myocardial ischemia are sufficient to result in permanent myocardial injury.
Despite remarkable progress in diagnosing patients with ACS, the identification of myocardial ischemia is still challenging, and physicians continue to admit the overwhelming majority of patients, often overestimating the likelihood of myocardial ischemia in low-risk patients. On the other hand, missing an ACS may lead to excess morbidity and mortality.
Platelets play a crucial role in the pathogenesis of atherosclerotic complications by contributing to thrombus formation or plaque rupture.
These newly formed platelets, often referred to as ‘‘reticulated’’ or ‘‘immature’’ platelets, lack genomic DNA but contain
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megakaryocyte-derived mRNA and thus have the translational capacity necessary for protein synthesis. Moreover, immature platelets are characterized by a higher number of dense granules and an increased platelet volume than older platelets. Finally, larger platelets have been shown to be enzymatically and metabolically more active and to have a higher thrombotic potential than smaller platelet.
Larger platelets are hemostatically more active (including aggregation and release of thromboxane A2, platelet factor 4, and thromboglobulin) and are a risk factor for developing coronary thrombosis, leading acute coronary syndromes. Platelet volume is a marker of platelet function, and activity and is measured using mean platelet volume (MPV).
Several studies have suggested a possible link between reticulated platelet and cardiovascular disease outcome. Elevated reticulated platelets have been identified as an independent risk factor for myocardial infarction in patients with coronary heart disease and for death or recurrent vascular events after myocardial infarction.
The aim of the present study was to evaluate reticulated platelets (RP) as a predicting factor in the outcome of acute coronary syndrome.
The present study was conducted on sixty five (65) subjects who were distributed into two groups; group I included 50 patients with ACS and group II included 15 normal subjects with matching age and sex as the control group. group I was subdivided into 3 subgroups; IA - included 19 patients (38%) were diagnosed as STEMI & IB – included 14 patients (28%) were diagnosed as Non STEMI and IC – included 17 patients (34%) were diagnosed as unstable angina.
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For all patients included in the study, a written consent was taken and an approval from the ethics committee of Faculty of Medicine, Menoufia University was approved. Full history was obtained and complete physical was performed.
Samples were drawn at time of presentation and were analyzed by an automated ADVIA-2120 hematological analyzer (Bayer Diagnostics, Newbury, United Kingdom) to measure (platelet count & mean platelet volume MPV) and measurement of reticulated platelet percentage (RP %) by immunophenotyping using the Becton-Dickinson Fluoresecence activated flowcytometer (FACS Calibur, BD immunecytometry systems, USA). .
The results of our study showed that:
1. There was not statistically significant in platelet count in patients with ACS compared to the control group.(p = 0.12)
2. The difference of platelet count was not statistically significant between patients with MI and those with UA (p = 0.47).
3. The MPV level was significantly increased in patients with ACS.
4. Highly significant positive correlation was observed between MPV and immature platelet fraction IPF% (r = −0.74, p < 0.001).
5. IPF% was higher in ACS patients than controls
6. IPF% was higher in STEMI than NTEMI and UA patients.
7. IPF% is significantly associated to cardiac risk factors including smoking, hypertension, diabetes mellitus and previous cardiac intervention.
8. IPF% was independent risk factor for acute cardiovascular diseases with odds ratio (1.9) and CI (1.01 – 19.87)