Abstract 17601: Left Atrial function Assessed by Cardiac Magnetic Resonance Imaging in Patients With Heart Failure With Preserved and Reduced Left Ventricle Ejection Fraction With and Without Symptoms

Abstract

Introduction: Increased left atrial volume (LAV) is considered a barometer for impaired left ventricular (LV) relaxation. In this study we examined the LAV and LA emptying function in patients with LV systolic (LVSD) and diastolic dysfunction (LVDD) with and without clinical heart failure (HF). Methods: Prospectively enrolled study participants (n=66) underwent cardiac MR (CMR) in a 1.5 T scanner. Patients with atrial fibrillation were excluded. LAV was assessed at end systole (ES) and at end diastole (ED) using area-length methods in cine MR 4-chamber and 2-chamber planes and indexed to body surface area. HF status was based on clinical manifestations, elevated BNP or NT-BNP. Patients also underwent echocardiogram within 2 hours of CMR. LV ejection fraction (LVEF) by CMR < 50% was defined as LVSD. Echocardiographic criteria and/or elevated LVED pressure by catheterization were applied to define LVDD. Results: LAV was significantly increased in HF patients. The greatest increase was seen among those with HFrEF. When compared to normal controls the magnitude of increase in LAV in HF patients was greater at ED than ES. Patients having LVSD and LVDD without clinical HF demonstrated relatively normal LAV at both ES and ED. While LA emptying function was significantly reduced in all HF patients the greatest reduction was found in HFpEF. LA boost function in late diastole was significantly increased only in LVDD (Table). Of the three LA indices, LA emptying function had the strongest correlation with (logarithm transformed) BNP (r = -0.62, p <0.001) and NT-BNP (r = -0.58, p <0.001) supporting its relationship with adverse hemodynamics. Conclusion: Significantly increased LAV and reduced LA emptying function were present in HFrEF and HFpEF. Heightened LA boost function with relatively normal LAV and emptying function was characteristic of LVDD without HF. These LA features demonstrate the importance of atrioventricular interdependence and may be valuable in clinical diagnosis.