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Background and Objective: Atherosclerosis and its complications are a major cause of ischemic heart diseases. Platelets play an important role in initiation of atherosclerosis and coronary thrombus formation. Large platelets are shown to be hemostatically more active. Evaluation of platelet volume parameters could be useful and significant in prediction and differentiation of coronary events. Methods: In this study, 100 patients with chest pain were divided into 3 groups according to clinical manifestation and standard diagnostic criteria. 25 patients were with unstable angina, 25 patients with chronic stable angina and 50 patients with non-cardiac chest pain as normal population. Platelet indices and count were assayed within 1 to 3 hours, after sampling from venous blood and collection in K3 EDTA, by a Sysmex KX21 analyzer. Data were provided for each group and surveyed by ANOVA and Tukey tests with Pearson correlation and P-value less than 0.05. Findings: Patients with unstable angina had a significant higher MPV (Mean platelet volume) (10.7±0.23 fl), PDW (Platelet distribution width) and PLCR (Platelet-lerge cell ratio) than those in chronic stable angina and normal group (P<0.05). MPV in chronic stable angina patients (10.1±0.2 fl) was higher than normal population (9.5±0.1 fl) but platelet count and other indices were not statistically significant difference. There were no sex or age differences in MPV amounts in population group. Conclusion: Platelet volume indices are increased in unstable angina probably because of platelet activation and a compensatory volume enhancement. Platelets count reduction in this condition results from platelet consumption. These changes in platelet count and volume could differentiate unstable angina patients from chronic stable patients and normal individuals.

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BACKGROUND AND OBJECTIVE: Cardiovascular diseases are the leading cause of mortality in Iran (46% of all deaths). 10-30% of patients referred to emergency ward had acute coronary syndrome (ACS), and 1-4% cases with acute coronary syndrome and 2-3% of patients with myocardial infarction discharged mistakenly. The aim of this study was to delineate final diagnosis and characteristics of patients admitted with primary diagnosis of acute coronary syndrome (ACS).
METHODS: This cross sectional study was performed on patients with primary diagnosis of acute coronary syndrome admitted in cardiac ward of Loghman hospital from 2003 to 2004. History and physical examination were done before hospitalization. After hospitalization, the result of echocardiography, angiography and electrocardiography was recorded for final diagnosis and then with considering clinical and paraclinical findings, diagnosis was confirmed. Also their family history, current smoking and history of myocardial infarction were surveyed. Test of X 2 and t-test were used for analyzing qualitative and quantitative variables respectively and p<0.05 was considered significant.
FINDINGS: From 1015 patients, 116 had primary diagnosis of acute coronary syndrome that 51.6% of patients were female and their mean age was 58.9±12.9 years. Their final diagnoses were acute myocardial infarction in 196 cases (32%), possible unstable angina in 159 cases (26%), definite/probable unstable angina in 135 cases (22%) and non cardiac chest pain in 121 (19.8%). Mean age of acute coronary syndrome group (490 cases) in comparison with non cardiac chest pain group (121 cases) was more. History of diabetes mellitus, hypertension and myocardial infarction were significantly lower in non cardiac chest pain group. Sex, family history and current smoking were not significantly different.
CONCLUSION: Considering about 20% of patients with non cardiac chest pain mistakenly hospitalized in cardiology ward, so it is recommended to provide suitable facilities for primary diagnosis in emergency ward to prevent improper hospitalization and discharge.