Impact of arterial load on left ventricular diastolic function in patients undergoing cardiac catheterization for coronary artery disease.

BACKGROUND Although left ventricular (LV) diastolic dysfunction is associated with increased risk for incident heart failure in patients with coronary artery disease (CAD), no specific treatment for diastolic abnormalities has been established. Animal and small human studies have shown that an acute increase in LV afterload adversely impacts on LV early diastolic relaxation, but little is known about its chronic effect on diastolic function. METHODS AND RESULTS The relationships of various components of arterial load (arterial compliance, total vascular resistance index, and augmentation index [AI] in the ascending aorta) with LV diastolic function indices determined on cardiac catheterization (relaxation time constant [Tau] and end-diastolic pressure [EDP]) and those on tissue Doppler echocardiography (early diastolic mitral annular velocity [E'] and the ratio of early diastolic mitral inflow to annular velocities [E/E']) were investigated in 303 consecutive patients undergoing cardiac catheterization for CAD. All components of arterial load correlated with diastolic function indices, with AI, an index reflecting late-systolic load, having the strongest correlations with diastolic function indices. After adjustment for potential confounders, AI correlated with Tau (standardized beta=0.25, P<0.001), EDP (beta=0.25, P<0.001), E' (beta=-0.21, P<0.001), and E/E' (beta=0.23, P<0.001). CONCLUSIONS Increased AI is independently associated with LV diastolic function in patients with known or suspected CAD. Late-systolic load may be a therapeutic target to improve LV diastolic abnormalities in this population.