Relationship between endothelial dysfunction and cardiovascular risk factors and the extent and severity of coronary artery disease.

OBJECTIVES: Endothelial dysfunction (ED) is associated with coronary artery disease (CAD) and cardiovascular risk factors. The relationship between cardiovascular risk factors, ED and the presence, extent and severity of CAD, was evaluated in patients with and without angiographically defined CAD in our study. STUDY DESIGN: Eighty patients with CAD and 20 subjects with normal coronary arteries were included. Endothelial function was evaluated by endothelium-dependent, flow-mediated dilatation (FMD) and nitroglycerine-mediated dilatation (NMD) measurements, using brachial artery Doppler ultrasonography (USG). Cardiovascular risk factors were identified. The extent and severity of CAD was determined via vessel and modified Gensini scores. RESULTS: FMD% and NMD% were significantly decreased in the CAD(+) group compared with the CAD(-) group (p=0.0001). In the CAD(+) group, the cut-off values of FMD% and NMD% in distinguishing between single-vessel and multi-vessel diseases were 8.5% (sensitivity: 95%, specificity: 62%) and 13.6% (sensitivity: 91%, specificity: 62%), respectively. Additionally, a modified Gensini score was significantly correlated with both FMD and NMD (r=-0.825, r=-0.778, respectively; p=0.0001) in the CAD(+) group. CONCLUSION: ED was more prevalent in the CAD(+) group, and the degree of ED correlated well with the extent and severity of CAD.

The relation between coronary flow rate, plasma endothelin-1 concentrations, and clinical characteristics in patients with normal coronary arteries.

BACKGROUND: Coronary slow flow (CSF) is characterized by delayed opacification of epicardial arteries in the absence of occlusive disease. In the present study, we aimed to investigate the relation between coronary flow rate, plasma endothelin-1 (ET-1) concentrations, and clinical characteristics in patients with normal coronary arteries. METHODS: The study population included 77 patients with angiographically normal coronary arteries who underwent coronary angiography on suspicion of ischemic heart disease due to typical chest pain or ischemic findings on treadmill exercise test or myocardial scintigraphy. Based on the Thrombolysis In Myocardial Infarction frame count (TFC), patients were grouped into those with normal coronary flow and those with slow coronary flow. RESULTS: Forty-eight (61.5%) patients were found to have CSF. Plasma ET-1 concentrations were significantly higher with the presence of CSF (P=.03). There were significant differences between plasma ET-1 concentrations, and mean TFC, TFC for left anterior descending coronary artery (LAD), TFC for left circumflex coronary artery (CX), and TFC for right coronary artery separately in patients with and without CSF (P=.033, P<.001, P<.001, P<.001, and P<.001, respectively). Mean TFC, TFC for LAD, and TFC for CX, and ET-1 concentrations were significantly higher in smokers than in nonsmokers (P<.001, P<.001, P=.004, and P=.033, respectively). However, logistic regression analysis suggested that ET-1 concentration was not an independent determinant of CSF. CONCLUSIONS: Although there is a significant relation between ET-1 concentrations and coronary flow rate, ET-1 concentrations are not sufficient to determine the presence of CSF. Smoking is strongly associated with CSF, TFC, and increased ET-1 concentrations.