Dilatation Of Thoracic Aorta Research Articles

Genetic variants in childhood-onset dilatation of thoracic aorta in a consanguineous population

IntroductionChildhood-onset thoracic aortic dilatation (TAD) is a heterogenous group of genetic conditions the inheritance of which is largely dominant. To our knowledge, the influence of consanguinity on childhood-onset TAD has not been addressed systematically. We aim to study a cohort of children with TAD in our highly consanguineous population. MethodsChildren with TAD were consecutively recruited. Based on the likelihood of a founder mutation, genetic test was categorized to either targeted gene testing or multi-gene sequencing, followed by genetic screening of first-degree relatives. Clinical data and outcome were reviewed. ResultsThirty-three children, from 20 families, had childhood-onset TAD. Genetic test was positive in 20 children, from 13 families, providing a yield of 65 % (13/20). The median age of onset of TAD was 4.5 years. Eight variants were detected in 4 genes (FBN1, EFEMP2, ACTA2, KANSL1) with a homozygous EFEMP2 variant found in 6 families (46.2 %). Surgical intervention was required in 14 (70 %) cases (13 with EFEMP2, 1 with FBN1 variants) at a median age of 3.5 years. All patients are alive (ages range:3–31 years). ConclusionsOur work illustrates the impact of consanguinity on the genetics of childhood-onset TAD elucidating severe presentation of recessively inherited form. Our data underscores the importance of genetic screening and early recognition of TAD to achieve excellent outcome.

Distal ascending aortic dilatation portends a near 2-fold greater risk of cardiovascular mortality than proximal enlargement: results from 120,000 patients in a nationwide echocardiographic database

Abstract Background The management of thoracic aortic dilatation is clinically challenging and acute aortic dissection (AD) is under-recognised as a primary cause of death. Despite the majority of AD occurring in non-severely dilated aortas, absolute aortic diameter remains the most utilised criterion for adjudging preventative surgical correction. In order to improve outcomes and guide management, greater prognostic understanding is needed. Purpose We examined a nationwide echocardiographic dataset linked to mortality outcomes to determine how ascending thoracic aortic dilatation and its site affects cardiovascular disease (CVD) mortality over time. Methods The National Echocardiography Database Australia (NEDA) was examined for aortic dimensions at the sinuses of Valsalva (SoV), sinotubular junction (STJ) and ascending aorta (AscAo) in patients who had undertaken >1 echocardiographic study. Following separation of those who had undergone corrective aortic surgery, patients were stratified according to absolute aortic diameters and grouped as normal (<4cm), mild (4.0-4.5cm), moderate (4.5-5cm) and severely (>5cm) dilated at the prescribed thoracic aortic sites. Mortality data was then linked from the National Death Index (NDI). Results 398,905 echocardiographs from 121,115 patients with a mean age of 62.6±16.2 years were included. At the time of mortality data linkage, 38,681 (32%) had died, of whom 13,292 (34%) died from CVD causes and only 276 (0.007%) had aortic dissection recorded as their primary cause of death. Severe aortic dilatation at any site increased the likelihood of 10-year CVD mortality (29% vs. 15% in those with normal diameters; HR 3.00; CI 1.60-5.63; p<0.0001), with an incremental increase in the probability of CVD death when moving from the proximal to distal ascending aorta; 10-year CVD mortality at the SoV 26% (HR 1.93; CI 1.29-2.87; p<0.001), STJ 39% (HR 2.82; CI 1.64-4.86; p<0.001) and AscAo 44% (HR 4.74; CI 2.46-9.13; p<0.001) respectively (Figure 1). When examining those patients who had undergone corrective aortic surgery, the likelihood of 10-year CVD mortality was comparable to the population with normal aortic diameters (17 vs. 15%, HR 1.1; CI 0.9-1.36; p=0.3) (Figure 2). Conclusion Severe aortic dilatation increases the probability of 10-year cardiovascular mortality. Interestingly, there is an incremental increase in the likelihood of CVD mortality when moving from the proximal to distal ascending aorta, with severe AscAo dilatation conferring a near 2-fold greater risk of CVD mortality compared with severe SoV aneurysms. Additionally, surgical aortic intervention nearly normalises survival probability to the population with healthy aortic diameters. These results identify new considerations for prognostication, risk stratification and surgical guidance of aortic repair.CVD mortality by aortic dilatationCVD mortality after aortic intervention

Automated Analysis of Thoracic Aortic Aneurysms Based on Chest Computed Tomography Data: a Population Study in Moscow

Background. Cardiovascular diseases remain a pressing issue associated with great economic burden and loss of earning capacity. Among them, thoracic aortic aneurysms pose a serious threat as they commonly develop asymptomatically. Patients with aneurysms are often diagnosed late, which contributes to higher mortality rates due to complications. For this reason, conducting new epidemiological studies on this problem in our country is relevant.Objective: to study the prevalence of pathological dilatation of the thoracic aorta in Moscow by means of artificial intelligence technologies (AITs) using chest computed tomography (CT) data.Material and methods. A retrospective analysis of chest CT data from 227,149 patients obtained in the period from October 2022 to October 2023 was performed using AITs.Results. The analysis revealed that 13.3% of patients exhibited signs of thoracic aortic dilatation, while 0.8% had aneurysm signs. The prevalence of thoracic aortic aneurysms in Moscow was 12.4 cases per 100,000 individuals. Males were more susceptible than females; aneurysms of the descending aorta were more typical for them, while aneurysms of the ascending aorta were more common in females. The incidence of thoracic aortic dilatation increased with age. Potential causes and strategies to minimize AIT errors were discussed.Conclusion. The results highlight the importance of opportunistic screening for thoracic aortic aneurysms to ensure timely detection and prevention of complications. It would be especially beneficial to men and elderly population. The effectiveness of AITs to support decision-making by radiologists analyzing chest CT results was confirmed. The study provides an important update to the data on the prevalence of thoracic aortic aneurysms in asymptomatic patients in Russia. The identified features make it possible to direct the diagnostic and prevention efforts more effectively.

The association of cardiovascular disease risk with coronary artery calcification and thoracic aortic dilation: a study in idiopathic inflammatory myopathies and systemic lupus erythematosus.

We aim to explore the prevalence of coronary artery calcification (CAC) and ascending/descending thoracic aorta (AA/DA) dilation in idiopathic inflammatory myopathies (IIM) and systemic lupus erythematosus (SLE) patients, and to assess associations between cardiovascular disease (CVD) risk factors and these imaging signatures. This study recruited 151 IIM patients, 140 SLE patients, and 195 controls. The CAC and AA/DA diameters were quantified using non-gated chest CT images. The independent samples t-test or Mann-Whitney test was chosen for comparisons of continuous variables between patients and healthy controls. For categorical data, comparisons were made using the chi-square test or Fisher's exact test. Multivariate regression or Spearman's correlation analysis was employed to probe the associations between CVD risk factors and Framingham risk score (FRS) with imaging signatures. The IIM and SLE patients showed significantly higher prevalence of CAC and AA/DA dilatation (P < 0.01). Age was a risk factor for both CAC and AA/DA dilatation in all cohorts (P < 0.01). In IIM patients, the AA/DA dilatation was associated with BMI (P = 0.05). In SLE patients, CAC was associated with the elevated CRP level (P = 0.05). Without CAC, both IIM and SLE patients showed significant correlations between AA/DA diameters and FRS (P < 0.01, P < 0.01). Only in SLE patients, the interleukin-6 (IL-6) level correlated with AA/DA diameters. The IIM and SLE patients more commonly exhibit CAC and AA/DA dilation. These subclinical atherosclerosis signs are associated with traditional CVD risk factors. For AID patients without CAC, AA/DA diameters could serve as a potential biomarker for early CVD risk. Key Points • The study characterized the manifestation of subclinical atherosclerosis imaging biomarkers (CAC, AA/DA dilation) in IIM and SLE patients. • AA/DA diameters could serve as an early imaging biomarker in clinical management for IIM and SLE patients with early-onset and no CAC present.

Leveraging genetic data to improve the care of patients with thoracic aortic dilation.

Leveraging genetic data to improve the care of patients with thoracic aortic dilation.

Inhibition of alphaV integrins with cilengitide downregulates in vitro pro-fibrotic events in aortic smooth muscle cells and limits in vivo thoracic aortic aneurysm progression

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health "Ricerca Finalizzata - Giovani Ricercatori" Background The ‘greatest artery’, i.e., the aorta, can be affected by either acute conditions or chronic disorders, such as the aneurysm, which is the segmental aortic dilation with at least 50% increase in the normal diameter. Aortic dilation can often lead to lethal events, such as aortic dissection and/or vessel rupture. The aneurysms occurring in the thoracic trait of the aorta (TAA) may depend on comorbidities, such as hypertension (i.e., sporadic non-syndromic TAA, sTAA), or on genetically determined conditions, such as Marfan syndrome (MFS). To date, the surgical replacement of aorta represents the most effective therapeutic approach in all TAA patients, since an etiologic pharmacological treatment is still lacking. Thus, the identification of novel disease targets is mandatory. Integrin receptors are key players in cellular mechanotransduction responses. Specifically, integrins containing αV subunit have been described as important mechanotransduction mediators and responsible for pro-fibrotic molecular events. Recently, it has been reported the effectiveness of a broad αV integrin inhibitor in limiting the TAA progression by acting on FAK/AKT/mTORC signaling pathway in a MFS in vivo model. However, the specific αV integrin subgroup directly involved in this detrimental process is yet not known. Purpose We evaluated the effectiveness of a specific αVβ3 and αVβ5 integrin inhibitor (i.e., cilengitide) in downregulating pro-fibrotic in vitro events on vascular smooth muscle cells (VSMC) isolated from TAA patients’ aortic wall, and in limiting in vivo thoracic aortic dilation on a MFS mice model. Results By comparison with healthy control (HC)-VSMC, both sTAA-VSMC and MFS-VSMC showed higher levels of αVβ3 and αVβ5 integrins as well as pro-fibrotic collagen I. The in vitro inhibition of these two αV integrins mediated by cilengitide resulted more effective in collagen I downregulation when compared with GLPG0187 (pan αV inhibitor). Noteworthy, the cilengitide-mediated αV integrin inhibition consistently tempered pro-fibrotic phenotype of sTAA- and MFS-VSMC by directly acting on both canonical (p-SMAD2/3) and non-canonical (p-ERK1/2) TGF-β downstream pathways and by downregulating mechanotransduction mediators (e.g., RhoA GTPase, ROCK1, talin-1). The 2D-echocardiographic results on MFS mice treated with cilengitide confirmed the greater effectiveness of this drug in limiting the TAA progression, in comparison not only with vehicle but also with the broad integrin inhibitor GLPG0187. Conclusion Altogether, our results improve the know-how on αV integrin inhibition, highlighting the role of cilengitide as potential target for future therapeutic approaches to limit TAA progression, both in sporadic and in MFS patients.

Connecting the dots: molecular pathways in bicuspid aortopathy explored

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Junta de Andalucía, Ministerio de Ciencia e Innovación Background Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation. It predisposes to thoracic aortic dilatation (TAD), aneurysm and dissection. The current consensus is that the genetic defect that leads to the aortic valve malformation also causes structural anomalies of the ascending aorta. Altered hemodynamics caused by the abnormal valve morphology would accelerate aortic media degeneration. Molecular markers and pathways involved in the aetiology and pathophysiology of bicuspid aortopathy are poorly understood. Objective To elucidate the molecular and cellular mechanisms of the disease and to identify potential predictive molecular markers using a well-established isogenic hamster model (T strain) with a high (∼40%) incidence of BAV TAD. Methods Comparative quantitative proteomics combined with Western blot and morpho-molecular analyses in the ascending aorta of tricuspid aortic valve (TAV) and BAV animals from the T strain and TAV animals from a control strain. This strategy allows exploring independently the genetic and hemodynamic effects on the aorta in genetically homogeneous populations. Results The major molecular defect in the aorta of genetically homogeneous BAV individuals is PI3K/AKT overactivation caused by alterations in the EGF, ANGII and TGF-β signalling pathways. PI3K/AKT affects the downstream eNOS, MAP2K1/2, NF-κB, mTOR and WNT pathways. Most of these alterations are seen in independent patient studies with different clinical presentations, but not in TAV hamsters from the T strain, which mainly show downregulation of the WNT pathway. Conclusions We identify a combination of defective interconnected molecular pathways, directly linked to the central PI3K/AKT pathway, common to both BAV-associated TAD patients and hamsters. The defects indicate a shift of smooth muscle cells towards the synthetic phenotype induced by endothelial-to-mesenchymal transition, oxidative stress and inflammation. WNT signalling represents a genetic factor that may cause aortic structural abnormalities and aneurysm predisposition, whereas hemodynamics is the main trigger of molecular changes, likely determining the progression of aortopathy. We identify twenty-seven novel potential biomarkers with high predictive value.

Abstract 2022: AlphaV Integrins Inhibition Downregulates Pro-fibrotic Events In Human Aortic Smooth Muscle Cells And Limits Thoracic Aortic Aneurysm Progression In Marfan Mice

Aortic dilation can often lead to lethal events, such as aortic dissection and/or vessel rupture. The aneurysms occurring in the thoracic aortic trait (TAA) may depend on comorbidities, such as hypertension, or on genetically determined conditions, such as Marfan syndrome (MFS). To date, the surgical replacement of aorta represents the most effective therapeutic approach in all TAA patients, since an etiologic pharmacological treatment is still lacking. Integrin receptors are key players in cellular mechanotransduction responses and the role of integrins containing αV subunit have been described as responsible for pro-fibrotic molecular events. Recently, it has been reported the effectiveness of a pan αV integrin inhibitor ( i.e. , GLPG0187) in limiting the TAA progression in MFS in vivo model. However, the specific αV integrin subgroup directly involved in this detrimental process is yet not known. We evaluated the effectiveness of the specific αVβ3 and αVβ5 integrin inhibitor cilengitide in downregulating pro-fibrotic in vitro events on MFS patients’ vascular smooth muscle cells (MFS-VSMC), and in limiting in vivo thoracic aortic dilation on a MFS mice model. By comparison with healthy control (HC)-VSMC, MFS-VSMC showed higher levels of αVβ3 and αVβ5 integrins as well as pro-fibrotic collagen I. When compared with GLPG0187, the cilengitide-mediated in vitro inhibition of these integrins determined a more effective downregulation of TGF-β downstream pathways (SMAD2/3 and ERK1/2) as well as a statistical tempered expression of pro-fibrotic mechanotransduction mediators, such as RhoA GTPase. The 2D-echocardiographic results on MFS mice (Fbn1 C1039G/+ ) treated with cilengitide confirmed the greater effectiveness of this drug in limiting the TAA progression, not only in comparison with vehicle but also with the broad pan αV integrin inhibitor GLPG0187. Altogether, our results improve the know-how on αV integrin involvement in MFS-TAA scenario, unveiling the specific detrimental role of αVβ3 and αVβ5 in this pathological context. The selective inhibition of these integrins exerted by cilengitide highlights the role of this compound as a potential and more targeted tool for future therapeutic approaches to limit TAA progression in MFS patients.

Demographical and Clinical Factors Predictive for Aortic Dilatation. When should we be Concerned about the Size?

Thoracic aortic aneurysms are often an accidental finding and result from a degenerative process. Medical therapy includes pharmacological control of arterial hypertension and smoking cessation, that slows the growth of aneurysms. An association between the dilatation of the ascending and abdominal aorta has been already reported. The aim of the study was to identify possible demographic and clinical factors that may implicate further imaging diagnostics in patients with ascending aorta dilatation. There were 181 (93 (53%) males and 88 (47%) females) patients with a median age of 54 (41-62) years who underwent cardiac magnetic resonance due to non-vascular diseases, were enrolled into retrospective analysis. Multivariable analysis revealed ascending aorta dilatation (odds ratios (OR) = 7.45, 95% confidence interval (CI): 1.98-28.0, p = 0.003) and co-existence of coronary artery disease (OR = 8.68, 95% CI: 2.15-35.1, p = 0.002) as significant predictors for thoracic descending aorta dilatation. In patients with abdominal aorta dilatation, the multivariable analysis showed a predictive value of ascending aortic dilatation (OR = 14.8, 95% CI: 2.36-92.8, p = 0.004) and age (OR = 1.04, 95% CI: 1.00-1.08, p = 0.027). In addition, cut-off values were established for age groups determining the risk of thoracic aorta dilatation over 49 years and abdominal aorta dilatation over 54 years. The results of our analysis showed predictive factors, including ascending aorta dilatation and co-existence of coronary artery disease, particularly over 49 years of age for thoracic, while ascending aorta dilatation and age, particularly over 54 years, for abdominal aorta dilatation. These features may be considered to increase clinical vigilance in patients with aortic diameter abnormalities.

Abstract 12129: Using a Polygenic Risk Score to Account for Genomic Risk Factors in a Model to Detect Individuals With Dilated Ascending Thoracic Aortas

Background: Ascending thoracic aortic dilation is a complex trait that involves modifiable and non-modifiable risk factors and can lead to thoracic aortic aneurysm and dissection. Clinical risk factors have been shown to predict ascending thoracic aortic diameter. Polygenic risk scores (PRS) are increasingly used to assess clinical risk for multifactorial diseases. The degree to which a PRS improves aortic diameter risk prediction is not known. In this study we tested the extent to which the addition of PRS to clinical prediction algorithms improves the prediction of aortic diameter. Methods: Training and validation cohorts comprised 6,790 Penn Medicine Biobank (PMBB) participants with clinical data linked to whole exome sequencing. Linear regression models integrated PRS weights derived from a large genome wide association study of thoracic aortic diameter in the UK biobank and were compared to the performance of the standard and a reweighted variation of the recently published AORTA Score. Results: The training cohort of 5,092 participants (56% male) had a median age of 61 years (IQR 52-70) with a mean ascending aortic diameter of 3.4 cm (SD 0.5). Compared to the AORTA Score which explained 29.1% (95% CI 27.9%-30.8%) of the variance in aortic diameter, AORTA Score + PRS (explained 29.7%, 95% CI 28.5%-30.9%), the reweighted AORTA score (explained 30.7%, 95% CI 29.4%-32.3%), and the reweighted AORTA Score + PRS (explained 31.5%, 95% CI 30.0%-32.8%) had superior performance. For the predictive ability to identify thoracic aortic diameter of ≥ 4 cm, the addition of a PRS to both the AORTA Score and the reweighted AORTA Score improved sensitivity at a range of model threshold values. The respective areas under the receiver operator characteristic curve for the AORTA Score + PRS (0.762, 95% CI 0.731-0.794) and reweighted AORTA Score + PRS (0.779, 95% CI 0.749-0.809) were greater than the standard AORTA Score (0.758, 95% CI 0.727-0.789) and reweighted AORTA Score (0.775, 95% CI 0.745-0.805). Conclusions: We demonstrated that inclusion of a PRS to the AORTA Score results in a small performance enhancement. Further investigation is necessary to determine if incorporation of genetics into clinical risk prediction improve outcomes for thoracic aortic disease.

Abstract 13710: Cardiac Platypnea-Orthodeoxia Syndrome: How the Stars Aligned

Case description: A 79-year-old man with recurrent falls, dyslipidemia and recent exercise intolerance presented after a fall. He was putting on shoes, lost his balance and fell. There was no pre-syncope, syncope, dyspnea, chest pain, palpitations or dizziness. On admission, vital signs were normal except oxygen saturation (O2 sat) 79% on room air (and no improvement with supplemental O2). An arterial blood gas (ABG) revealed partial pressure of oxygen 42 mmHg with oxygen saturation 80%. He had lower thoracic spine tenderness, normal respiratory and cardiac exam. CT head showed no acute intracranial abnormalities. CTA chest had no pulmonary embolism, arterio-venous malformations or parenchymal lung disease. There was a thoracic aorta aneurysm (4.5cm at aortic root and 5.1cm at posterior arch). Subsequently, O2 sat was 92% supine and 79% standing. He also had a compression fracture of T12 and spinal asymmetry. A transesophageal echocardiogram (TEE) showed an aneurysmal, hypermobile interatrial septum with early right to left shunt with agitated saline due to a large patent foramen ovale (PFO). Right heart catheterization revealed no pulmonary hypertension and confirmed a step down from the pulmonary vein to left atrium (delta O2 sat 6%). A 30mm Gore Cardioform occluder was used to close the defect and immediately supplemental oxygen was removed, and O2 sat on room air was 95%. Follow up echocardiogram showed no residual shunt and exercise intolerance resolved. Discussion: Unexplained positional hypoxemia raised our suspicion for cardiac POS. Hypoxemia is caused by right to left shunting via the PFO, exacerbated by the thoracic aortic aneurysm and spinal changes such as the T12 fracture and spinal asymmetry. Going from being recumbent to erect there is stretching of the atria causing his PFO to enlarge, increasing the shunt. Additionally, the dilated thoracic aorta exerts mechanical pressure on the right atrium (RA) and interatrial septum, increasing PFO patency and augmenting flow from the inferior vena cava through the PFO. The spinal abnormality may cause more aortic distortion and exert forces on the RA, exacerbating shunting. Percutaneous PFO closure is the treatment of choice with closure immediately leading to significant improvement of hypoxemia.

Impact of Variation in Commissural Angle between Fused Leaflets in the Functionally Bicuspid Aortic Valve on Hemodynamics and Tissue Biomechanics.

In subjects with functionally bicuspid aortic valves (BAVs) with fusion between the coronary leaflets, there is a natural variation of the commissural angle. What is not fully understood is how this variation influences the hemodynamics and tissue biomechanics. These variables may influence valvar durability and function, both in the native valve and following repair, and influence ongoing aortic dilation. A 3D aortic valvar model was reconstructed from a patient with a normal trileaflet aortic valve using cardiac magnetic resonance (CMR) imaging. Fluid-structure interaction (FSI) simulations were used to compare the effects of the varying commissural angles between the non-coronary with its adjacent coronary leaflet. The results showed that the BAV with very asymmetric commissures (120∘ degree commissural angle) reduces the aortic opening area during peak systole and with a jet that impacts on the right posterior wall proximally of the ascending aorta, giving rise to elevated wall shear stress. This manifests in a shear layer with a retrograde flow and strong swirling towards the fused leaflet side. In contrast, a more symmetrical commissural angle (180∘ degree commissural angle) reduces the jet impact on the posterior wall and leads to a linear decrease in stress and strain levels in the non-fused non-coronary leaflet. These findings highlight the importance of considering the commissural angle in the progression of aortic valvar stenosis, the regional distribution of stresses and strain levels experienced by the leaflets which may predispose to valvar deterioration, and progression in thoracic aortic dilation in patients with functionally bicuspid aortic valves. Understanding the hemodynamics and biomechanics of the functionally bicuspid aortic valve and its variation in structure may provide insight into predicting the risk of aortic valve dysfunction and thoracic aortic dilation, which could inform clinical decision making and potentially lead to improved aortic valvar surgical outcomes.

Impact of retraining a deep learning algorithm for improving guideline-compliant aortic diameter measurements on non-gated chest CT

Purpose/objectiveReliable detection of thoracic aortic dilatation (TAD) is mandatory in clinical routine. For ECG-gated CT angiography, automated deep learning (DL) algorithms are established for diameter measurements according to current guidelines. For non-ECG gated CT (contrast enhanced (CE) and non-CE), however, only a few reports are available. In these reports, classification as TAD is frequently unreliable with variable result quality depending on anatomic location with the aortic root presenting with the worst results. Therefore, this study aimed to explore the impact of re-training on a previously evaluated DL tool for aortic measurements in a cohort of non-ECG gated exams. Methods & materialsA cohort of 995 patients (68 ± 12 years) with CE (n = 392) and non-CE (n = 603) chest CT exams was selected which were classified as TAD by the initial DL tool. The re-trained version featured improved robustness of centerline fitting and cross-sectional plane placement. All cases were processed by the re-trained DL tool version.DL results were evaluated by a radiologist regarding plane placement and diameter measurements. Measurements were classified as correctly measured diameters at each location whereas false measurements consisted of over-/under-estimation of diameters. ResultsWe evaluated 8948 measurements in 995 exams. The re-trained version performed 8539/8948 (95.5%) of diameter measurements correctly. 3765/8948 (42.1%) of measurements were correct in both versions, initial and re-trained DL tool (best: distal arch 655/995 (66%), worst: Aortic sinus (AS) 221/995 (22%)). In contrast, 4456/8948 (49.8%) measurements were correctly measured only by the re-trained version, in particular at the aortic root (AS: 564/995 (57%), sinotubular junction: 697/995 (70%)). In addition, the re-trained version performed 318 (3.6%) measurements which were not available previously. A total of 228 (2.5%) cases showed false measurements because of tilted planes and 181 (2.0%) over-/under-segmentations with a focus at AS (n = 137 (14%) and n = 73 (7%), respectively). ConclusionRe-training of the DL tool improved diameter assessment, resulting in a total of 95.5% correct measurements. Our data suggests that the re-trained DL tool can be applied even in non-ECG-gated chest CT including both, CE and non-CE exams.

Assessing the role of an artificial intelligence assessment tool for thoracic aorta diameter on routine chest CT.

To assess the diagnostic accuracy and clinical impact of automated artificial intelligence (AI) measurement of thoracic aorta diameter on routine chest CT. A single-centre retrospective study involving three cohorts. 210 consecutive ECG-gated CT aorta scans (mean age 75 ± 13) underwent automated analysis (AI-Rad Companion Chest CT, Siemens) and were compared to a reference standard of specialist cardiothoracic radiologists for accuracy measuring aortic diameter. A repeated measures analysis tested reporting consistency in a second cohort (29 patients, mean age 61 ± 17) of immediate sequential pre-contrast and contrast CT aorta acquisitions. Potential clinical impact was assessed in a third cohort of 197 routine CT chests (mean age 66 ± 15) to document potential clinical impact. AI analysis produced a full report in 387/436 (89%) and a partial report in 421/436 (97%). Manual vs AI agreement was good to excellent (ICC 0.76-0.92). Repeated measures analysis of expert and AI reports for the ascending aorta were moderate to good (ICC 0.57-0.88). AI diagnostic performance crossed the threshold for maximally accepted limits of agreement (>5 mm) at the aortic root on ECG-gated CTs. AI newly identified aortic dilatation in 27% of patients on routine thoracic imaging with a specificity of 99% and sensitivity of 77%. AI has good agreement with expert readers at the mid-ascending aorta and has high specificity, but low sensitivity, at detecting dilated aortas on non-dedicated chest CTs. An AI tool may improve the detection of previously unknown thoracic aorta dilatation on chest CTs vs current routine reporting.

The false lumen problem.

The false lumen problem.

Flow dynamics in a model of a dilated thoracic aorta prior to and following prosthetic replacement

We numerically investigate the flow dynamics in a model of a dilated thoracic aorta, and compare the flow features with the case of a prosthetic replacement in its ascending part. The flow is characterized by an inlet jet which impacts the aortic walls and sweeps toward the aortic arch. Secondary flows generated by the transvalvular jet evolve downstream into a helical flow. The small curvature radius at the end of the aortic arch induces flow separation and vortex shedding in the initial part of the descending aorta, during the systole. The implantation of a prosthesis determines several modifications in the global and local flow patterns. An increase of the pulse wave velocity in the aorta leads to larger pressures inside the vessel, due to the geometrical and rigidity modifications. The sweeping jet is more aligned along the axial direction and propagates faster along the aortic arch. Consequently, a stronger separation of the flow downstream of the aortic arch is observed. By also exploiting manifold analysis, we identify regions characterized by near-wall disordered flows which may present intense accumulation and drop of concentration of biochemicals. These regions are localized downstream of the prosthetic replacement, in the aortic arch, and may be more prone to a new emergence of vessel dilation.Graphical

Value of aortic volumes assessed by automated segmentation of 3D MRI data in patients with thoracic aortic dilatation: A case-control study

PurposeThe purpose of this study was to investigate the benefit of aortic volumes compared to diameters or cross-sectional areas on three-dimensional (3D) magnetic resonance imaging (MRI) in discriminating between patients with dilated aorta and matched controls. Materials and methodsSixty-two patients (47 men and 15 women; median age, 66 years; age range: 33–86 years) with tricuspid aortic valve and ascending thoracic aorta aneurysm (TAV-ATAA) and 43 patients (35 men and 8 women; median age, 51 years; age range: 17–76 years) with bicuspid aortic valve and dilated ascending aorta (BAV) were studied. One group of 54 controls matched for age and sex to patients with TAV-ATAA (39 men and 15 women; median age, 68 years; age range: 33–81 years) and one group of 42 controls matched for age and sex to patients with BAV (34 men and 8 women; median age, 50 years; age range: 17–77 years) were identified. All participants underwent 3D MRI, used for 3D-segmentation for measuring aortic length, maximal diameter, maximal cross-sectional area (CSA) and volume for the ascending aorta. ResultsAn increase in ascending aorta volume (TAV-ATAA: +107%; BAV: +171% vs. controls; P < 0.001) was found, which was three times greater than the increase in diameter (TAV-ATAA: +29%; BAV: +40% vs. controls; P < 0.001). In differentiating patients with TAV-ATAA from their controls, the indexed ascending aorta volume showed better performances (AUC, 0.935 [95% confidence interval (CI): 0.882–0.989]; accuracy, 88.7% [95% CI: 82.9–94.5]) than indexed ascending aorta length (P < 0.001), indexed ascending aorta maximal diameter (P = 0.003) and indexed ascending aorta maximal CSA (P = 0.03). In differentiating patients with BAV from matched controls, indexed ascending aorta volume showed significantly better performances performance (AUC, 0.908 [95% CI: 0.829–0.987]; accuracy, 88.0% [95% CI: 80.9–95.0]) than indexed ascending aorta length (P = 0.02) and not different from indexed ascending aorta maximal diameter (P = 0.07) or from indexed ascending aorta maximal CSA (P = 0.27) ConclusionAortic volume measured by 3D-MRI integrates both elongation and luminal dilatation, resulting in greater classification performance than maximal diameter and length in differentiating patients with dilated ascending aorta or aneurysm from controls.

A Study on the Difference in the Diameter of the Thoracic Aorta according to the Use of Contrast Medium in Computed Tomography

Computed tomography imaging has become a recognized and widely used procedure for the evaluation of patients with aortic dissection, stenosis or aneurysm. In CT, an accurate assessment of the size of the aorta plays a key role in detecting the aneurysm and determining how to treat it. However, despite this pivotal role of CT, there is little data on how accurately a CT scan measures the size of the actual thoracic aorta. Specialists in the Department of Radiology have determined that if the diameter of the thoracic aorta is greater than 40 ㎜, there is a finding of thoracic aortic dilatation, but if these criteria differ from non-contrast CT and Contrast CT, the determination may be difficult, and research is needed. This study was to present the average value and difference in diameter measurement of the thoracic aorta in non-contrast and contrast multi-detection computed tomography images and to see how the value varies with gender, age, and vendor.

Prevalence and development of aortic dilation and dissection in women with Turner syndrome: a systematic review and meta-analysis

Objectives Women with Turner syndrome (TS) have an increased risk of aortic disease, reducing their life-expectancy. This study aimed to systematically review the prevalence of thoracic aortic dilatation, aortic dimensions and growth, and the incidence of aortic dissection in adult TS women. Methods A systematic literature search was conducted up to July 2022. Observational studies with an adult TS population were included, studies including children aged < 15 years old or a specific TS population were excluded. Results In total 21 studies were included. The pooled prevalence of ascending aortic dilatation was 23% (95%CI 19-26) at a mean pooled age of 29 years (95%CI 26-32), while the incidence of aortic dissection was 164 per 100.000 patient-years (95%CI 95-284). Three reporting studies showed aortic growth over time to be limited. Risk factors for aortic dilation or dissection were older age, bicuspid aortic valve, aortic coarctation and hypertension. Conclusion In adult women with TS, ascending aortic dilatation is common and the hazard of aortic dissection increased compared to the general population, whereas aortic growth is limited. Conventional risk markers do not explain all aortic dissection cases, therefore new imaging parameters and blood biomarkers are needed to improve prediction, allowing for patient-tailored follow-up and surgical decision making.

Relationship Between Ascending Thoracic Aortic Diameter and Blood Pressure: A Mendelian Randomization Study.

Observational studies identified elevated blood pressure (BP) as a strong risk factor for thoracic aortic dilation, and BP reduction is the primary medical intervention recommended to prevent progression of aortic aneurysms. However, although BP may impact aortic dilation, aortic size may also impact BP. The causal relationship between BP and thoracic aortic size has not been reliably established. Genome-wide association studies summary statistics were obtained for BP and ascending thoracic aortic diameter (AscAoD). Causal effects of BP on AscAoD were estimated using 2-sample Mendelian randomization using a range of pleiotropy-robust methods. Genetically predicted increased systolic BP, diastolic BP, and mean arterial pressure all significantly associate with higher AscAoD (systolic BP: β estimate, 0.0041 mm/mm Hg [95% CI, 0.0008-0.0074]; P=0.02, diastolic BP: β estimate, 0.0272 mm/mm Hg [95% CI, 0.0224-0.0320]; P<0.001, and mean arterial pressure: β estimate, 0.0168 mm/mm Hg [95% CI, 0.0130-0.0206]; P<0.001). Genetically predicted pulse pressure, meanwhile, had an inverse association with AscAoD (β estimate, -0.0155 mm/mm Hg [95% CI, -0.0213 to -0.0096]; P<0.001). Multivariable Mendelian randomization analyses showed that genetically predicted increased mean arterial pressure and reduced pulse pressure were independently associated with AscAoD. Bidirectional Mendelian randomization demonstrated that genetically predicted AscAoD was inversely associated with pulse pressure (β estimate, -2.0721 mm Hg/mm [95% CI, -3.1137 to -1.0306]; P<0.001) and systolic BP (β estimate, -1.2878 mm Hg/mm [95% CI, -2.3533 to -0.2224]; P=0.02), while directly associated with diastolic BP (0.8203 mm Hg/mm [95% CI, 0.2735-1.3672]; P=0.004). BP likely contributes causally to ascending thoracic aortic dilation. Increased AscAoD likely contributes to lower systolic BP and pulse pressure, but not diastolic BP, consistent with the hemodynamic consequences of a reduced aortic diameter.