Endothelial functional and structural impairment in patients with different degrees of coronary artery disease development.

Flow-mediated dilatation (FMD) and intima-media thickness (IMT) are noninvasive methods for patient evaluation. In this study we aimed to estimate the correlation between FMD and IMT in patients with different degree of coronary artery disease (CAD) development, and to explore their prognostic significance for the presence of angiographically significant coronary artery stenosis. We included 198 patients divided into five groups according to the degree of CAD development. All patients had FMD and IMT measured, 105 (53.03%) performed a Treadmill test in our clinic, and 146 (73.7%) underwent coronary arteriography (CAG). Patients with significant (> or = 50%) coronary artery stenosis had lower FMD and higher IMT values compared to patients without significant CAD: FMD: 2.78% +/- 2.71% vs 8.24% +/- 5.16%, respectively, P < 0.001; IMT: 0.882 +/- 0.17 mm vs 0.763 +/- 0.16 mm, respectively, P < 0.001. There existed a weak negative correlation between FMD and IMT (correlation coefficient: 0.242, P < 0.001), which was lost in subgroups and after controlling for the presence of significant CAD, number of diseased coronary arteries, and percent coronary artery stenosis. Analyzing the receiver operating characteristic curves we found that FMD values < or = 4.5% had 74% sensitivity, 77% specificity, positive predictive value (PPV) 81.8%, and negative predictive value (NPV) 68%, and IMT values > or = 0.81 mm had sensitivity 71%, specificity 67%, PPV 76.1%, and NPV 63.1% for the presence of significant CAD. Patients with advanced CAD had lower FMD and higher IMT values compared to patients with minor changes. The correlation between FMD and IMT was weak and inconsistent. Both methods demonstrated an acceptable prognostic significance for the presence of significant CAD.