Correlation of endothelial dysfunction measured by flow-mediated vasodilatation to severity of coronary artery disease

Abstract

Objectives: Brachial artery ultrasound imaging during reactive hyperemia is widely used tool for quantifying endothelium dependent vasomotion. Angiodefender device is used for non invasive determination of percentage flow mediated vasodilation (FMD). An attempt is made to study whether endothelial dysfunction determined by FMD of brachial artery predicts the presence or absence of coronary artery disease and its correlation with the severity of coronary artery disease.

Methods: One hundred six patients admitted between May 2014 and April 2015 who were posted for coronary angiography diagnosed to have chronic stable angina on clinical basis and/or by exercise stress test, for evaluation of coronary artery disease were submitted to standard clinical evaluation, calculation of percentage FMD by Angiodefender device. Statistical significance of difference of categorical variables was tested using Fisher's exact test. Sensitivity, specificity, positive predictive value and negative predictive value of FMD were studied.

Results: There was no correlation between number of risk factors and percentage of FMD. Significantly higher proportion of cases with less FMD had higher prevalence of coronary artery disease and vice-versa. Significantly higher proportion of cases with positive stress test had less percentage of FMD and vice-versa. Significantly higher proportion of cases with less percentage of FMD and positive stress test had higher prevalence of obstructive coronary artery disease and vice-versa. Specificity was 100% when percentage of FMD was ≤10.

Conclusions: FMD an inexpensive and non-invasive test provides information regarding extent and severity of coronary artery disease.

Keywords: Coronary angiography; Coronary artery disease; Endothelial dysfunction; Flow mediated vasodilatation; Stress test.