الفهرس 
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Abstract
Under physiological conditions, the vascular endothelium produces many substances that contribute importantly to hemostasis, fibrinolysis, and regulation of vessel tone and permeability. One such substance is glycoprotein von Willebrand factor (vWf), which is almost exclusively produced by the endothelium, and thus is a marker of endothelial activation or dysfunction. vWf mediates platelet adhesion to the vascular wall, platelet aggregation and serves as a plasma carrier for factor VIII, stabilizing it in the circulation. Since almost all acute coronary syndromes (ACSs) result from thrombus formation in preexisting atherosclerosis, and given the key role of vWf in arterial thrombus formation, this biomarker attracted considerable interest as a predictor of cardiovascular disease (CVD).
Previously published studies suggest that there is a weak association between vWf plasma levels and risk of coronary heart disease (CHD) in general population, but its predictive value significantly rises in patients with preexisting vascular disease, diabetics, and the elderly. It was noticed that vWf rises during the course of ACSs, and it is thought that vWf is not only a marker, but also a mediator in the pathogenesis of myocardial infarction (MI). Although a number of studies pointed out the prognostic value of vWf, there is still a long way to go before plasma vWf levels can be used as a predictor of cardiovascular disease in clinical practice.
In this regards, our study aimed to evaluate the role of vWF as marker for prognosis in association with other inflammatory marker such as hs-CRP in patients with acute coronary syndrome.
The study was conducted on 50 patients with ACS presented to emergency department within 6 hours of chest pain. According to the final discharge diagnosis, patients were classified in to 11 patients with unstable angina and 39 patients with acute myocardial infarction of which 13 patients had non ST elevation myocardial infarction and 26 patients had ST elevation myocardial infarction.
All patients included in this study were subjected to full medical history, clinical examination, routine laboratory investigations including complete blood picture, lipid profile, liver function tests and biomarkers of myocardial necrosis (CK, CK-MB).
In all patients vWF:Ag was measured at admission and after 48 hours from treatment using Sysmex 1500 coagulation analyzer for the quantitative determination of vWF:Ag in human plasma by immunoturbidimetry. Also hs-CRP was measured for all patient at admission and after 48hours from treatment using Stat Fax-2100 (ELISA Reader) for quantitative determination of hs-CRP in human serum by immunoenzymometric assay.
Reassessment of vWF and hs-CRP after 48h of starting treatment was done then patients classified to improved and not improved patients according to the clinical success and angiographic success
von Willebrand Factor level was higher in patients with myocardial infarction than patients with unstable angina butdidn’t reach to the statistical significance, there was significant difference in vWF level and hs-CRP level before and after treatment in all studied groups. Both parameters had significant difference between different methods of treatment as they both was higher in PCI treatment than medical treatment. However, no significant difference was observed between STEMI and non STEMI regarding all studied risk factors and both parameters.
Correlation studies of vWF and hs-CRP before vs after, revealed a significant correlation between vWF before vs after and significant correlation between hs- CRP before vs after.
Other correlation study between studied parameters and outcome, revealed a high significant difference, in the contrary, there was no significant correlation between studied risk factors and the outcome.
Receiver operating characteristic curve (ROC) analysis was applied to assess the prognostic utility of vWF in ACS patients collectively. The best cut off for vWF was 132. This had a prognostic sensitivity of 84.4%, specificity 55.6%, negative predictive value 66.7% and positive predictive value 77.1%. The area under the curve (AUC) was 0.708.
In conclusion, vWF and hs-CRP levels are increased in both AMI and UA at attack and decreased after 48h of therapy. Addtionally, thier increased levels were associated with bad outcome and related to the used lines of therapy. Lastly, the results of our study point out to vWF as sensitive and good prognostic marker.