The Genetic Determinants of Aortic Distension

As the largest conduit vessel, the aorta is responsible for the conversion of phasic systolic inflow from ventricular ejection into more continuous blood delivery to peripheral arteries. Distension during systole and recoil during diastole conserves ventricular energy and is enabled by the specialized composition of the aortic extracellular matrix. Aortic distensibility decreases with age and prematurely in vascular disease. To discover genetic determinants of aortic distensibility we trained a deep learning model to quantify aortic size throughout the cardiac cycle and calculate aortic distensibility and aortic strain in 42,342 participants in the UK Biobank with available cardiac magnetic resonance imaging. In up to 40,028 participants with genetic data, common variant analysis identified 12 and 26 loci for ascending and 11 and 21 loci for descending aortic distensibility and strain, respectively. Of the newly identified loci, 22 were specific to strain or distensibility and were not identified in a thoracic aortic diameter GWAS within the same samples. Loci associated with both aortic diameter and aortic strain or distensibility demonstrated a consistent, inverse directionality. Transcriptome-wide analyses, rare-variant burden tests, and analyses of gene expression in single nucleus RNA sequencing of human aorta were performed to prioritize genes at individual loci. Loci highlighted multiple genes involved in elastogenesis, matrix degradation, and extracellular polysaccharide generation. Characterization of the genetic determinants of aortic function may provide novel targets for medical intervention in aortic disease.

Abstract P143: Assessment Of Biventricular And Aortic Function In Arterial Systemic Hypertension By Speckle Tracking Echocardiography

Background: The purpose of the present study was to assess whether systemic arterial hypertension is associated with abnormal right ventricular (RV) structure and function as assessed by three-dimensional speckle tracking echocardiography and how those changes are related to left ventricular (LV) strain, left ventricular hypertrophy (LVH) and aortic (Ao) function. Methods: We examined 115 hypertensive (mean age, 65±16 years; 52% male) and 115 healthy adults (mean age, 68±13 years; 54% male). Patients were divided into two groups: patients with LVH (Group I, LVMI>115g/m 2 men, LVMI>95g/m 2 women) and patients without LVH (group II). LV longitudinal (LS), circumferential, radial and area (GAS) strains were calculated by three-dimensional speckle tracking echocardiography (3DSTE). RV free-wall longitudinal strain (LS) was determined by 3DSTE. Aortic (Ao) distensibility and stiffness index (SI) were calculated using accepted formulae. The corrected aortic strain (Ao-S) by two-dimensional speckle tracking echocardiography was calculated as the global aortic strain /pulse pressure. Data analysis was performed offline (GE EchoPAC). Results: Overall, Ao-SI was increased (r=0.74, p=0.003) and Ao-S was decreased (r=0.79, p=0.002) in hypertensive patients compared with controls. Ao-SI had a negative correlation with Ao-S (r=-0.76, p<0.001). Ao-S correlated with LV and RV longitudinal strain (r=0.62,p=0.02, and r=0.58,p<0.05, respectively) and LV and RV area strain (r=0.66,p=<0.01, and r=0.53,p<0.05, respectively). RV-LS and LV-GAS were lower in Group 1 patients compared to Group 2 (r=0.81, p<0.001), and lower in Group 2 patients compared to controls (r=0.59, p=0.02). There was a positive correlation between LV and RV LS (r=0.52, p<0.05). RV-LS was independently associated with Ao-S (β=0.37, p=0.01), LV-GAS (β=0.32, p=0.027) and LV-LS (β=0.26, p=0.034) in the whole hypertensive population. Conclusions: In systemic hypertension there is a complex interaction between LV strain, RV strain and Ao strain. Reduced RV strain can occur even in the absence of LV hypertrophy.

Low serum 25-Hydroxy (OH) vitamin D levels are associated with increased arterial stiffness in healthy children: An echocardiographic study from Turkey

Objective: Arterial stiffness refers to arterial wall rigidity, particularly in central vessels, and is an independent predictor of cardiovascular disease. 25-Hydroxy (OH) vitamin D has beneficial effects on blood pressure, vascular endothelial function, and arterial stiffness. Therefore, we aimed to elucidate the role of 25-OH vitamin D deficiency in arterial stiffness development and its relationship with arterial stiffness in healthy children. Methods: This study included 80 patients with low levels of 25-OH vitamin D and 40 healthy control. The study participants were then divided into three groups: group 1 consisted of patients with a deficient 25-OH D level of < 19.9 ng/mL, group 2 with an insufficient 25-OH D level between 20-29.9 ng/mL; group 3 were considered control group with a sufficient serum 25-OH vitamin D level of ≥30 ng/mL. Aortic strain, distensibility, stiffness index, and standard left ventricular measurements were calculated using M-mode echocardiographic data. Results: Left ventricular mass index (LVMI) and interventricular septal diastolic thickness (IVSTd) appeared to increase in group 1 compared to groups 2 and 3. Aortic strain and distensibility were significantly decreased in group 1, whereas aortic stiffness index and elastic modulus were significantly increased. The aortic stiffness index was negatively correlated with serum 25-OH vitamin D levels; however, aortic strain, aortic distensibility, and LVMI were positively correlated. Conclusions: Our study results revealed a significant relationship between 25-OH vitamin D levels indicative of a deficiency and aortic stiffness. We suggest that arterial stiffness may also occur in healthy children with a 25-OH vitamin D deficiency.

Dynamic changes in aortic stiffness after substantial weight loss by laparoscopic sleeve gastrectomy in patients with obesity: a 1-year follow-up study

Arterial stiffness has been identified as a powerful and independent risk factor for cardiovascular disease. Obesity is associated with an increased risk of aortic stiffness (AS) and adverse cardiovascular events. Herein, we aimed to evaluate the effects of weight loss after laparoscopic sleeve gastrectomy (LSG) on AS in individuals with morbid obesity by using the transthoracic echocardiography (TTE).A total of 53 patients with obesity (17 males, 36 females) who underwent LSG and did not have any known heart disease were included in the study. The AS parameters were measured with TTE. The demographic and echocardiographic data of the patients were studied before, at 1 month and 12 months after surgery.The mean age of the study group was 34.41±11.62, 68% of whom were female. There were no significant differences in terms of the standard echocardiography and Doppler measurements as compared with preoperative values (all p>0.05). When the elastic parameters of the aorta were compared, no significant differences were detected regarding aortic strain (%) ((16.28±4.11) vs (16.68±4.56), p=(0.998)), distensibility (cm2/dyn) ((6.74±1.78) vs (7.03±2.31), p=(0.997)) and Aortic Stiffness Index values ((10.73±3.84) vs (10.63±3.34), p=0.998) between baseline and first month after surgery. In the 12-month follow-up, it was determined that the aortic strain ((16.28±4.11) vs (22.74±5.79), p≤0.001) and distensibility ((6.74±1.78) vs (10.34±3.059), p<0.001)) values increased at significant levels.Weight loss by LSG improves arterial stiffness parameters in patients with obesity over a 1-year follow-up.

Left Ventricular Systolic Dyssynchrony Index and Endothelial Dysfunction Parameters As Subclinical Predictors of Cardiovascular Involvement in Patients with Beta-Thalassaemia Major

Objective: Cardiovascular involvement due to iron overload is the leading cause of morbidity and mortality in patients with beta-thalassaemia major (β-TM). However many patients remain asymptomatic until the late stage. In this study, we investigated the role of real-time three-dimensional echocardiography (RT3DE) findings and endothelial dysfunction parameters in asymptomatic β-TM patients, and the relationship between these parameters and cardiac magnetic resonance imaging (MRI) T2 * value. Methods: 51 asymptomatic β-TM patients who were receiving regular blood transfusions were evaluated by two-dimensional echocardiography (2DE) and RT3DE examinations including endothelial dysfunction parameters. The study population was divided into two subgroups based on their cardiac MRI T2* values (MRI T2* ≤20ms and >20ms). The relationships between serum ferritin levels, 2DE and RT3DE measurements, endothelial dysfunction parameters, and cardiac MRI T2* values were investigated. Results: Although all left ventricle ejection fraction (LVEF) values obtained by 2DE were within normal limits (≥50%), they were not associated with MRI T2* values. LVEFRT3D (53.25 +2.33 vs 58.81 +1.02), SDI12 (6.53 +0.56 vs 2.85 +0.48), SDI16 (7.65 +0.75 vs 3.26 +0.49) were significantly different and negatively correlated between two groups respectively . Flow-mediated dilatation (FMD) (6.08% + 0.34 vs 14.46% + 1.12), aortic strain (7.79% + 2.19 vs 12.76% + 4.19), and serum ferritin values were significantly different and negatively correlated between two groups respectively. Conclusion: Decreased LVEF and increased SDI by RT3DE could be parameters of early cardiac deterioration. Decreased FMD and aortic strain may be good predictors of subclinical cardiovascular involvement in asymptomatic patients with β-TM.

The effect of Celiac disease on cardiac functions and aortic elasticity parameters in children

Aim: We aimed to investigate the effect of Celiac disease on myocardial functions and aortic elasticity parameters. Materials and Methods: Thirty children with Celiac disease and 30 healthy children were enrolled in the study. Both the groups were similar in terms of age and gender. Cardiac functions of all children in the patients and control group were evaluated using conventional transthoracic echocardiography and tissue Doppler imaging. Aortic strain, distensibility, and stiffness index were calculated by M-mode echocardiography. Results: The demographic findings, height, weight, and body mass index of cases were similar among two groups. No statistical difference was found between E wave velocity for conventional transthoracic echocardiography and tissue Doppler imaging measurements of the mitral valve; early diastolic flow peak velocity, A wave velocity; late diastolic flow peak velocity; and E/A ratio. Isovolumetric relaxation time and isovolumetric contraction time ratios were statistically different between the groups (p = 0.000, p = 0.000, p = 0.000). The myocardial performance index calculated according to the pulse Doppler measurement results was found to be statistically different between the groups (p = 0.000). There was no statistical difference between the groups in terms of aortic strain, distensibility, and stiffness index. Conclusion: In this study, both conventional transthoracic echocardiography and tissue Doppler imaging revealed the affection of the myocardial functions during systole and diastole in children with Celiac disease. Therefore, early follow-up and routine cardiac evaluation of celiac patients may be appropriate due to the increased risk of cardiac affection.