Abstract Body (Do not enter title and authors here): Background:
Heart failure with preserved left ventricular ejection fraction (LVEF) prevails in subjects who complained of exercise intolerance, which is characterized by elevated left ventricular filling pressure (LVFP). While arterial stiffness has been related to left ventricular diastolic dysfunction, little is known whether the coronary flow reserve mediates the association. The invasive study then investigated the correlations between arterial stiffness, coronary flow reserve and LVFP.

Methods:
Subjects, referred for coronary angiography were eligible for this study and patients with stenotic lesions coronary artery disease (CAD) over 70% in any of which coronary vessels were excluded. Pressure waveforms of right radial artery (RRA), ascending aorta, and left ventricle were obtained, and left ventricular end-diastolic pressure (LVEDP) were measured. Aortic augmentation index (AI), aorto-radial pulse wave velocity (arPWV), and left ventricular diastolic time constant (Tau) were calculated. Three-dimensional quantitative coronary angiography (3D-QCA)-based vessel FFR (vFFR) of each coronary artery were measured. Increased LVFP was defined as LVEDP ≥ 20mmHg.

Results:
Among a total of 244 participants, 152 subjects had increased LVFP. While the demographic data, morbidities, hemogram, biochemistries, blood pressure, FFR, and LVEF were almost similar between groups, subjects with increased LVFP had higher RRA AI, aortic AI, subendocardial viability ratio, and Tau. Stepwise regression showed subendocardial viability ratio and Tau played the crucial role while increased LVFP. Correlation matrix analysis showed aortic AI, Tau, and RRA AI and all three vessels vFFR correlated with LVEDP. The multiple logistic regression analysis demonstrated positive correlation between radial AI, and Tau but inversely correlation between subendocardial viability ratio and no correlation between three vessels vFFR with increased LVFP.

Conclusions:
Among subjects with CAD but no stenotic lesions over 70% among three vessels, aortic stiffness was associated with elevated LVFP, suggesting some hemodynamic impacts of central arterial stiffness on LV filling impairment patients with normal left ventricular systolic function. About coronary flow reserve and other diastolic indices, represented with vFFR and subendocardial viability ratio and Tau, respectively, the discordance results among correlation matrix and logistic regression analysis needs further studies to investigate.