Interobserver and intraobserver variability of flow-mediated vasodilatation of the brachial artery

Effects of statins on endothelial function in patients with coronary artery disease

BACKGROUND

Flow-mediated dilatation (FMD) of the brachial artery is a method capable of detecting endothelium dysfunction. Statins are generally consent drugs for reducing cardiovascular morbidity and mortality and are shown to improve the systemic endothelial function.

HYPOTHESIS

The aim of our study was to assess the endothelial function using FMD of the brachial artery in patients with different degrees of coronary artery stenosis with respect to their treatment with statins.

METHODS

We evaluated the FMD of 221 patients with coronary arteriography performed, of whom 99 (44.8%) were receiving statins and 122 (55.2%) were not receiving statins.

RESULTS

We did not find a statistically significant difference in the FMD values between the patients with and without a statin treatment: 5.57 +/- 5.68 and 4.69 +/- 4.48, respectively, P = .581. In the subgroup of patients without angiographically visible coronary artery stenoses or with stenoses <20% (86 patients), patients undergoing statin treatment had a significantly better endothelial function compared to patients without such a treatment: FMD 9.24 +/- 6.87 and 6.50 +/- 4.51, respectively, P = .047.

CONCLUSIONS

FMD could not distinguish between the patients who were treated with statin and those not treated with statins with the same demographic, clinical, and angiographic characteristics. The only exception was in the group of patients with a minor coronary disease. Statin treatment had a more pronounced effect in the earlier stages of coronary atherosclerosis.

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.