Aortic Stiffness and Distensibility as Predictor to Severity of Coronary Artery Disease

Study Overview
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Brief Summary
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Assess the relationship of Aortic root distensibility and stiffness with the extent of coronary artery disease as assessed by SYNTAX score compared to a matched cohort of patients with normal coronary angiography

Detailed Description
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Cardiovascular disease leading cause of death, resulting in a number of annually deceased people higher than from any other. The great incidence of cardiovascular diseases in the world spurred the search for new solutions to enable an early detection of pathological processes The early detection based in multi-parameters of pathological condition is the key to the patient survival .The arterial stiffness is the first vessels modification, responsible for several pathological processes, which can lead to cardiovascular diseases. The normal aging process is associated with an increase in vascular stiffness which is accelerated by atherosclerosis, hypertension, and diabetes mellitus. Several studies have revealed that increased aortic stiffness is a risk factor for cardiovascular diseases and also is a predictor of cardiovascular morbidity and mortality. Interest in arterial stiffness waned in the early 1900s with the advent of the sphygmomanometer, which offered a quantitative measure of blood pressure and risk prediction . Another factor is Aortic distensibility which is a measurement of vascular elasticity, and reflects the stiffness of the aorta . Aortic distensibility is markedly decreased in patients with known coronary artery disease . and is inversely proportional to the severity of Coronary artery disease . Two-dimensional and tissue Doppler imaging derived parameters of ascending aorta have been found to be abnormal, indicating increased Aortic stiffness and impaired Aortic distensibility in subjects with coronary artery disease, hypertension, and diabetes mellitus. However, the direct correlation of Aortic stiffness with Coronary artery disease is hard to examine as most of these patients are old and have comorbidities such as hypertension, So Investigation of these parameters should be done in patients who are normotensive as most of these patients do not have confounding factors that increase Aortic stiffness. Although the relationship between Aortic distensibility and Aortic stiffness and atherosclerosis is well known , the possible relation between them and the extent and complexity of coronary artery disease. as assessed using SYNTAX score has not been clearly determined yet. The SYNTAX score is a lesion-based angiographic scoring system originally devised to grade the complexity of coronary artery disease. . It is related to adverse cardiovascular events and predicts mortality and morbidity in patients with coronary artery disease.

Official Title
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Aortic Root Distensibility And Stiffness Assessed By Echocardiography As Predictors Of Coronary Artery Lesion Severity In Coronary Artery Patients Undergoing Coronary Angiography

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: echocardiography and coronary angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: all patients suspected to have coronary artery disease Exclusion Criteria: -Hypertension( SBP>140mmhg or DBP>90mmhg) Previous coronary stenting Previous CABG Renal diseases. Decompensated liver disease. Connective tissue diseases. Aortic valve disease ( more than mild aortic stenosis or regurgitation)

Ages Eligible for Study
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Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| normal<br>patient complains of anginal chest pain but coronary angiography is normal | Diagnostic Test: echocardiography and coronary angiography<br>* transthoracic echocardiography will be done for all subjects to measure aortic stiffness and elaticity then coronary angiography was used to differentiate between normal subjects and who have coronary artery disease<br>|
| coronary artery disease<br>patient complains of chest pain with coronary angiography showing atherosclerotic plaques causing luminal obstruction | Diagnostic Test: echocardiography and coronary angiography<br>* transthoracic echocardiography will be done for all subjects to measure aortic stiffness and elaticity then coronary angiography was used to differentiate between normal subjects and who have coronary artery disease<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| compare aortic stiffness and elasticity in normal subjects and patient with coronary artery disease | aortic stiffness by echocardiography ⊿P=Ps-Pd mmHg. ⊿D=As-Ad cm. local arterial stiffness can be calculated using the following formula: Aortic distensibility (AD) cm2/dyn= (2x⊿D)/((Adx⊿p)) Aortic stiffness index(SI)= ln (Ps/Pd)/(⊿D/Ad) no units ln is the natural logarithm Arterial strain = (⊿D)/Ad no units The elastic modulus E(p) = (⊿P)/Strain ( mmHg/cm) tissue doppler imaging (TDI) The TDI of expansion peak velocity during systole (SAo) and early (EAo) and late (AAo) diastolic peak velocities (m/s)are obtained then coronary angiography will be done to differentiate the 2 groups into normal and others have coronary artery disease using Syntax score( SS) Patients were divided into three tertiles: SS LOW ≤22 22< SSMID ≤32 SS HIGH >32 | 1 hour |