Relationship between endothelial function, aortic stiffness, and ventricular-arterial interaction in patients with heart failure : endothelial function in heart failure

Abstract

Background/Aims: Endothelial dysfunction and aortic stiffness are associated with each other and they are often present together in patients with heart failure. Increase of aortic stiffness causes pressure loading and increase of the left ventricular stiffness so that abnormal ventricular-arterial interaction phenomenon arises. The aim of this study is to determine endothelial function and to investigate relationship between endothelial function, aortic stiffness and associated arterial wave reflection characteristics, and ventricular-arterial interaction in heart failure patients with reduced left ventricular systolic function.Methods: A total of 38 patients who were hospitalized acute heart failure, ischemic or non-ischemic, with left ventricular ejection fraction (LVEF) <45% were enrolled in this study. We also included 8 normal control patients without any cardiovascular disease, risk factors, symptoms, and medication. Before discharge with stabilization of heart failure symptoms, global endothelial function was assessed as the ratio of the maximum change in augmentation index (AIx) after administration of albuterol relative to nitroglycerin. Central aortic pressure waveform was generated using radial artery applanation tonometer. Ventricular-arterial interaction index was calculated by the ratio of arterial elastance relative to ventricular elastance (Ea/Ees).Results: In patients with heart failure, a significant fall in AIx of -18.9 ± 7.6% (p <0.001) and -8.2 ± 5.8% (p <0.001) was noted after administration of nitroglycerin and albuterol, respectively. Global endothelial function was more severely impaired in patients with heart failure compared with the control patients (0.45 ± 0.18 vs. 0.72 ± 0.07, p <0.001). Global endothelial function was positively correlated with LVEF (r = 0.538, p = 0.001) and inversely with Ea/Ees (r = -0.396, p = 0.019) and peripheral (r = -0.602, p <0.001) and central pulse pressure (r = -0.418, p = 0.022). The patients with heart failure showed significantly lower baseline AIx (13.9 ± 11.1 vs. 24.0 ± 16.2%, p = 0.038) and higher aortic pulse wave velocity (PWV, 8.8 ± 2.4 vs. 6.3 ± 1.0 m/s, p <0.001) than the control patients. Aortic PWV was also positively associated with LVEF (r = 0.389, p = 0.019) and negatively with Ea/Ees (r = -0.362, p = 0.030).Conclusion: Global endothelial function was significantly impaired in patients with systolic heart failure. This global endothelial function is positively correlated with left ventricular systolic function and negatively with ventricular-arterial interaction index.