P12 Role of CT measured epicardial adipose tissue in moderate to severe aortic stenosis

Introduction Epicardial adipose tissue (EAT) exerts paracrine effects on the myocardium. More lipid-laden adipocytes, with lower attenuation on computed tomography (CT), are associated with greater pro-inflammatory activity. We aim to compare EAT in patients with aortic stenosis (AS) and healthy controls and explore correlations with cardiac remodelling.

Methods Asymptomatic patients with AS and controls were prospectively recruited and underwent non-contrast cardiac CT, magnetic resonance imaging (MRI) and transthoracic echocardiography (TTE). Fully automated volumetric quantification of EAT with an attenuation of -190 to -30 Hounsfield units (HU) was performed. A cut off of -90HU determined higher and lower attenuation adipose tissue.

Results 124 patients with AS (max. velocity 3.88±0.57m/s, aortic valve area index 0.57±0.15 cm2/m2) and 39 controls were included. Mean EAT attenuation was significantly lower in AS compared to controls (-75.94±5.47 vs -69.93±5.4 HU, p<0.001). Indexed total (53.21±21.78 vs 41.72±18.2 cm3/m2, p=0.003) and low attenuation (16.92 [8.48, 22.53] vs 9.4 [5.7, 13.5]cm3/m2, p <0.001) EAT volumes were significantly higher in AS compared to controls.

On univariate analysis, indexed total and low attenuation EAT volumes were associated with measures of diastolic dysfunction: longitudinal (r=-0.266, p=0.004 and r=-0.220, p=0.017) and circumferential peak early diastolic strain rate (r -0.245, p=0.008 and r=-0.203, p=0.029) on CMR and E/e’ (r=0.194, p=0.034 and r=0.192, p=0.036) on TTE, but not independent of age, BMI and AS severity.

Conclusion Total and low attenuation indexed EAT volumes were higher in AS compared to controls and associated with diastolic dysfunction, but not independent of age, BMI and AS severity.