P3416Low gradient severe aortic stenosis with preserved ejection fraction: reclassification of severity by 3D transesophageal echocardiography

Abstract

Background: Low gradient severe aortic stenosis (AS) with preserved left ventricular ejection fraction (LVEF) may be due to aortic valve area (AVA) underestimation with 2D transthoracic echocardiography (TTE). We aimed to evaluate whether calculation of AVA using 3D transesophageal echocardiography (TEE) resulted in significant reclassification of AS severity. Method(s): Echocardiographic data was collected from 2013 to 2017. We classified the population of severe AS patients (AVA<1 cm2) according to pressure gradient (>= or <40 mmHg) and flow state (>= or <35 ml/m2) into four groups: Low Flow/Low Gradient (LF/LG); Low Flow/High Gradient (LF/HG); Normal Flow/Low Gradient (NF/LG); Normal Flow/High Gradient (NF/HG). Patients with LF/LG severe AS and preserved LVEF (>50%) in which a TEE had been performed where studied. AVA using 3D TEE planimetry was calculated. Measurements were performed by two different operators and interobserver reproducibility was assessed. Clinical and echocardiographic characteristics as well as BNP levels were considered. Result(s): Forty patients with LF/LG severe AS with preserved LVEF had undergone a TEE. 90.9% of patients had hypertension, 34.1% diabetes, 20.5% smoked, 51.1% chronic renal failure, 7% chronic obstructive pulmonary disease, 46.5% coronary artery disease. Mean LVEF was 66%. During follow-up 58.1% of patients underwent aortic valve replacement. Calculation of AVA using 3D TEE planimetry reclassified 17.5% of patients into moderate AS. AVA calculated using 3D TEE showed a better correlation with BNP levels (rho spearman = -0.7740, p<0,001) than 2D TTE AVA (rho spearman = -0.3808, p=0,15). Intra-class correlation coefficient (ICC) for absolute agreement was 0.91. Conclusion(s): Calculation of AVA using 3D TEE planimetry seems a useful tool for the subgroup of patients with low gradient severe AS with preserved LVEF where diagnosis may be challenging. In our cohort, calculation of AVA using 3D TEE planimetry reclassified 17.5% of patients into moderate AS. AVA calculated using 3D TEE showed a better correlation with BNP levels than 2D TTE AVA.