21 The Effect of Severe Aortic Stenosis on Aortic Haemodynamic Flow-Parameter Differences Between Bicuspid and Tri-leaflet Valve Morphology: a 4D Flow Study

Introduction Bicuspid aortic valve (BAV) is associated with earlier onset valvulo-aortopathy including aortic stenosis (AS) and aortic root dilatation than tri-leaflet aortic valves (TAV). Altered aortic haemodynamic flow patterns are linked with increased risk of BAV-associated aortopathy.1–3 Incremental effects of AS on these are unclear. Materials and Methods 4D flow cardiovascular magnetic resonance (4DF-CMR) was performed on 32 patients (11 BAV, 21 TAV, mean age 68 ± 10 years) with severe symptomatic AS (aortic valve area ≤ 1 cm2) and 17 healthy controls (8 BAV, 9 TAV, mean age 57 ± 7 years). In-plane peak velocity and maximum wall shear stress (WSS) were evaluated from 2D analysis planes at the aortic root and distal ascending aorta (AAo) using commercial software. Peak systolic 3D volumetric velocities and vorticities averaged over the AAo (aortic root to level of pulmonary artery bifurcation) were generated using in-house Matlab code. All comparisons were adjusted for age and diastolic blood pressure. Results In-plane peak velocities (300 ± 74 vs 176 ± 53 cm/s) and WSS at the AAo, as well as volume averaged peak velocities (434 ± 92 vs 239 ± 127 cm/s) and vorticities (152 ± 26 vs 91 ± 26 rad) were significantly higher (p Discussion 4DF-CMR demonstrated pathological aortic haemodynamic patterns in patients with severe AS compared to controls. Haemodynamic differences were also measurable in the ascending aorta of asymptomatic BAV compared to TAV controls. These differences were no longer significant in the presence of AS. Conclusion Abnormal flow patterns in asymptomatic BAV become indistinguishable from those of TAV in the presence of severe AS, suggesting AS induces similar pathological changes in aortic haemodynamics, independent of valve morphology.</p

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 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.</p

Aortic valve intervention rates in patients of different ethnicity with severe aortic stenosis in Leicestershire, UK

ObjectivesTo explore the ethnic differences in patients undergoing aortic valve (AV) intervention for severe aortic stenosis (AS) in Leicestershire, UK.MethodsRetrospective cohort study of all surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) at a single tertiary centre between April 2017 and March 2022, using local registry data.ResultsOf the 1231 SAVR and 815 TAVI performed, 6.5% and 3.7% were in ethnic minority patients, respectively. Based on the 2011 Census data for those with a Leicestershire postcode, crude cumulative rate of SAVR (n=489) was 0.64 per 1000 population overall and 0.69, 0.46 and 0.36 in White, Asian and Black populations, respectively; and 0.50 per 1000 population overall for TAVI (n=383), with 0.59, 0.16 and 0.06 for White, Asian and Black populations, respectively. Asians undergoing SAVR and TAVI were 5 and 3 years younger, respectively, than white patients with more comorbidities and a worse functional status.The age-adjusted cumulative rates for SAVR were 0.62 vs 0.72 per 1000 population for White and Asian patients and 0.51 vs 0.39 for TAVI. Asians were less likely to undergo SAVR and TAVI than White patients, with a risk ratio (RR) of 0.66 (0.50–0.87) and 0.27 (0.18–0.43), respectively, but the age-adjusted RR was not statistically significant.ConclusionThe crude rates of AV interventions are lower in Asian patients compared with the White population in Leicestershire, although age-adjusted rates were not statistically different. Further research to determine the sociodemographic differences in prevalence, incidence, mechanisms and treatment of AS across the UK is required

Impact of diabetes on remodelling, microvascular function and exercise capacity in aortic stenosis

Objective To characterise cardiac remodelling, exercise capacity and fibroinflammatory biomarkers in patients with aortic stenosis (AS) with and without diabetes, and assess the impact of diabetes on outcomes. Methods Patients with moderate or severe AS with and without diabetes underwent echocardiography, stress cardiovascular magnetic resonance (CMR), cardiopulmonary exercise testing and plasma biomarker analysis. Primary endpoint for survival analysis was a composite of cardiovascular mortality, myocardial infarction, hospitalisation with heart failure, syncope or arrhythmia. Secondary endpoint was all-cause death. Results Diabetes (n=56) and non-diabetes groups (n=198) were well matched for age, sex, ethnicity, blood pressure and severity of AS. The diabetes group had higher body mass index, lower estimated glomerular filtration rate and higher rates of hypertension, hyperlipidaemia and symptoms of AS. Biventricular volumes and systolic function were similar, but the diabetes group had higher extracellular volume fraction (25.9%±3.1% vs 24.8%±2.4%, p=0.020), lower myocardial perfusion reserve (2.02±0.75 vs 2.34±0.68, p=0.046) and lower percentage predicted peak oxygen consumption (68%±21% vs 77%±17%, p=0.002) compared with the non-diabetes group. Higher levels of renin (log10renin: 3.27±0.59 vs 2.82±0.69 pg/mL, p Conclusions In patients with moderate-to-severe AS, diabetes is associated with reduced exercise capacity, increased diffuse myocardial fibrosis and microvascular dysfunction, but not cardiovascular events despite a small increase in mortality.</p