value of endothelium dependent vasodilatation in diagnosing coronary artery disease and its comparison with the results of routine diagnostic tests

ABSTRACT

To determine the predictive value of flow-mediated vasodilation [FMD] compared with angina pectoris, exercise electrocardiography, and myocardial perfusion imaging [MPI]. This study was carried out in Shahid Madani Heart Center, Tabriz, Iran from April 2004 to September 2006. A total of 92 patients with chest pain syndrome were enrolled in this study. Using high resolution ultrasound system endothelial function was evaluated, and the result of the flow-mediated dilation [FMD%] was defined as the percent change in the internal diameter of the brachial artery during reactive hyperemia related to baseline. Coronary artery disease [CAD] was documented in 77 [83.7%] patients. The percentage of FMD was lower in patients with CAD compared with those without it [3.55 +/- 3.71 versus 10.76 +/- 4.61,P=0.001]. In comparison with typical anginal chest pain [sensitivity 46.7%, specificity 80%], exercise stress test [sensitivity 75%, specificity 60%], and MPI [sensitivity 96.5, specificity 55.6%] the receiver operator characteristic curve showed the percentage FMD optimal cut-off value as sensitivity of 87.0%, specificity of 66.7%, negative predictive value of 93.0%, and positive predictive value of 50%. In patients with chest pain syndrome, the FMD is a sensitive indicator of CAD with moderate specificity that is unable to predict accurately the extent and severity of it