Evaluation of ghrelin levels and endothelial functions in patients with coronary slow flow phenomenon

BACKGROUND: Ghrelin has recently been reported to have beneficial effects on cardiac contractile functions and coronary blood flow. The main purpose of this study was to investigate the role of ghrelin in the pathogenesis of coronary slow flow (CSF) together with endothelial functions. METHODS: Twenty-five patients having normal coronary arteries with CSF and 25 controls with normal coronary flow were included into the study. The quantitative measurement of coronary blood flow was performed for each coronary artery using the thrombolysis in myocardial infarction (TIMI) frame count (TFC) method. Ghrelin levels were measured using the enzyme-linked immunosorbent assay method from venous blood samples. Endothelial functions were evaluated from the brachial artery with the flow-mediated dilation (FMD) and nitrate-related dilation methods. RESULTS: There was a significant difference in terms of mean TFC values between the control and CSF groups (p < 0.001 for all coronary arteries). The mean FMD percentage among patients with CSF was lower than that of the control group (5.9 ± 0.8 vs. 10.7% ± 1.1%; p < 0.001). A moderate negative correlation was observed between the FMD percentages and the TFCs. There was no relationship between the TFC and ghrelin levels. CONCLUSION: Plasma ghrelin levels seem to be uninfluential while impaired endothelial functions play an important role in the etiopathogenesis of CSF.