What is the appropriate size criterion for resection of thoracic aortic aneurysms?

Aortic events and relative survival in patients with moderately dilated proximal thoracic aorta

Objectives. This study describes growth, local and remote aortic events, and survival in patients with proximal (root, ascending) aortic diameters just below threshold for operation. Methods. Patients with proximal aortic diameter of 4.5 to 5.4 cm at baseline, were followed with serial computed tomography studies and data collected retrospectively. Aortic growth rate was estimated using mixed effects modelling. Clinical and radiological features associated with outcomes (all-cause death, aortic death, local or remote aortic events (dissection, rupture, intramural hematoma, or intervention)) were assessed with Cox analysis. Survival and freedom from events were estimated using Kaplan-Meier methods. Results. 80 patients underwent 274 CT scans during 265 patient-years. Median proximal aortic growth was 0.2 cm in 3 years. 32 events occurred in 28 patients (35%). Eleven events were local, all elective proximal aortic surgery. Nine events were remote: 5 type B aortic dissections, 3 descending aneurysms undergoing elective repair, and one infrarenal aortic rupture. Twelve patients died, half of type B aortic dissection. Relative survival compared to a matched normal population was 82% (95% confidence limits 55-98%) at 10 years. In Cox analysis, increased descending aortic diameter was an independent predictor of all-cause death (hazard ratio [HR], 1.39) and aortic death (HR 1.96). Conclusions. Descending, but not proximal, aortic growth was predictive of lethal events. The decreased relative survival, the substantial number of remote aortic events and aortic deaths strongly suggest continuous serial CT surveillance of the entire aorta. Other indicators than proximal aortic diameter appear needed to improve management of this patient group.

Patient-specific ascending aortic intervention criteria

OBJECTIVES

Ascending aortic aneurysms pose a different risk to each patient. We aim to provide personalized risk stratification for such patients based on sex, age, body surface area and aneurysm location (root versus ascending).

METHODS

Root and ascending diameters, and adverse aortic events (dissection, rupture, death) of ascending thoracic aortic aneurysm patients were analysed. Aortic diameter was placed in context vis-a-vis the normal distribution in the general population with similar sex, age and body surface area, by conversion to z scores. These were correlated of major adverse aortic events, producing risk curves with 'hinge points' of steep risk, constructed separately for the aortic root and mid-ascending aorta.

RESULTS

A total of 1162 patients were included. Risk curves unveiled generalized thresholds of z = 4 for the aortic root and z = 5 for the mid-ascending aorta. These correspond to individualized thresholds of less than the standard criterion of 5.5 cm in the vast majority of patients. Indicative results include a 75-year-old typical male with 2.1 m2 body surface area, who was found to be at increased risk of adverse events if root diameter exceeds 5.15 cm, or mid ascending exceeds 5.27 cm. An automated calculator is presented, which identifies patients at high risk of adverse events based on sex, age, height, weight, and root and ascending size.

CONCLUSIONS

This analysis exploits a large sample of aneurysmal patients, demographic features of the general population, pre-dissection diameter, discrimination of root and supracoronary segments, and statistical tools to extract thresholds of increased risk tailor-made for each patient.

Differential expansion and outcomes of ascending and descending degenerative thoracic aortic aneurysms

OBJECTIVE

To evaluate expansion of degenerative thoracic aortic aneurysms (TAAs) and compare results between ascending and descending TAAs.

METHODS

Among patients with diagnosis of degenerative TAA (1995-2015) in Olmsted County, we studied those having at least 2 computed tomography scans of TAA throughout the follow-up. Patients were classified as ascending or descending groups according to the segment where the maximal aortic diameter was measured. Primary end points were expansion rates and factors associated with TAA growth.

RESULTS

We investigated 137 patients, 70 (51.1%) of whom were women; 78 (56.9%) were in the ascending and 59 (43.1%) were in the descending group. Median baseline maximal aortic diameter was 48.5 mm (interquartile range, 47.0-49.9 mm) for ascending and 42.4 mm (interquartile range, 40.0-45.4 mm) for descending group (P < .001). Median expansion rate was higher in the descending than the ascending group (2.0 mm/year [interquartile range, 0.9-3.2 mm/year] vs 0.2 mm/year [IQR, 0.1-0.6 mm/year]; P < .001). Aneurysm in the descending aorta and larger baseline maximal aortic diameter were independently associated with TAA expansion. Advanced age and chronic obstructive pulmonary disease but not aneurysm size or location were independently associated with overall mortality (P < .05). Aneurysm in the descending aorta was associated with aortic-related events (P < .05).

CONCLUSIONS

Degenerative TAAs under surveillance expand slowly. Descending TAA and larger baseline maximal aortic diameter were independently associated with more rapid TAA expansion, but these factors did not influence all-cause mortality.

Computed Tomography Scan of the Aorta to Predict Type B Aortic Dissection

BACKGROUND

 The purpose of this study is to find the high-risk morphological features in type B aortic dissection (TBAD) population and to establish an early detection model.

METHODS

 From June 2018 to February 2022, 234 patients came to our hospital because of chest pain. After examination and definite diagnosis, we excluded people with previous cardiovascular surgery history, connective tissue disease, aortic arch variation, valve malformation, and traumatic dissection. Finally, we included 49 patients in the TBAD group and 57 in the control group. The imaging data were retrospectively analyzed by Endosize (Therevna 3.1.40) software. The aortic morphological parameters mainly include diameter, length, direct distance, and tortuosity index. Multivariable logistic regression models were performed and systolic blood pressure (SBP), aortic diameter at the left common carotid artery (D3), and length of ascending aorta (L1) were chosen to build a model. The predictive capacity of the models was evaluated through the receiver operating characteristic (ROC) curve analysis.

RESULTS

 The diameters in the ascending aorta and aortic arch are larger in the TBAD group (33.9 ± 5.9 vs. 37.8 ± 4.9 mm, p < 0.001; 28.2 ± 3.9 vs. 31.7 ± 3.0 mm, p < 0.001). The ascending aorta was significantly longer in the TBAD group (80.3 ± 11.7 vs. 92.3 ± 10.6 mm, p < 0.001). Besides, the direct distance and tortuosity index of the ascending aorta in the TBAD group increased significantly (69.8 ± 9.0 vs. 78.7 ± 8.8 mm, p < 0.001; 1.15 ± 0.05 vs. 1.17 ± 0.06, p < 0.05). Multivariable models demonstrated that SBP, aortic diameter at the left common carotid artery (D3), and length of ascending aorta (L1) were independent predictors of TBAD occurrence. Based on the ROC analysis, area under the ROC curve of the risk prediction models was 0.831.

CONCLUSION

 Morphological characteristic including diameter of total aorta, length of ascending aorta, direct distance of ascending aorta, and tortuosity index of ascending aorta are valuable geometric risk factors. Our model shows a good performance in predicting the incidence of TBAD.

Ascending thoracic aortic aneurysm size at presentation and growth by diameter

AIM

To investigate the hypothesis that lung cancer screening allows for earlier identification of ascending thoracic aortic aneurysms (aTAAs) and that growth rates for aTAAs are greatest at larger sizes.

MATERIALS AND METHODS

This single referral centre retrospective study manually gathered computed tomography (CT) data from 732 patients presenting from July 2002 to August 2022. Five hundred and seventeen patients with aTAA >39 mm were identified to compare presenting diameter by year of presentation. Four hundred and thirty-two patients had CT examinations >3 months apart, allowing for growth analysis. Patients were separated by initial examination date (before or after 12/31/2013) for presenting size comparison. Patients were then divided into five groups based on aTAA diameter for growth rate analysis.

RESULTS

At identification, patients had a median aTAA diameter of 44 mm (IQR 41-47 mm). Patients with aTAAs identified prior to December 2013 (n=129) had an average aTAA diameter 1.7 mm larger than those identified later (n=388; p=0.003). The growth analysis showed an average growth rate of 0.1 mm/year (p<0.001) across the entire cohort. Patients with an aTAA diameter of ≥55 mm (n=12) grew the fastest at 1.9 mm/year (p<0.001). In the <40 mm group (n=43), the aTAAs expanded at 0.2 mm/year, faster than the 0.1 mm/year of the slowest expanding 45-49 mm group (n=130; p=0.04).

CONCLUSION

aTAA size at discovery was larger before lung cancer screening guidelines took effect in December 2013. The largest aTAAs expanded fastest, but growth rates were slowest in the medium-sized 45-49 mm diameter group.

Fate of the unoperated ascending thoracic aortic aneurysm: three-decade experience from the Aortic Institute at Yale University

AIMS

This study aims to outline the 'true' natural history of ascending thoracic aortic aneurysm (ATAA) based on a cohort of patients not undergoing surgical intervention.

METHODS AND RESULTS

The outcomes, risk factors, and growth rates of 964 unoperated ATAA patients were investigated, over a median follow-up of 7.9 (maximum of 34) years. The primary endpoint was adverse aortic events (AAE), including dissection, rupture, and aortic death. At aortic sizes of 3.5-3.9, 4.0-4.4, 4.5-4.9, 5.0-5.4, 5.5-5.9, and ≥6.0 cm, the average yearly risk of AAE was 0.2%, 0.2%, 0.3%, 1.4%, 2.0%, and 3.5%, respectively (P < 0.001), and the 10-year survival free from AAE was 97.8%, 98.2%, 97.3%, 84.6%, 80.4%, and 70.9%, respectively (P < 0.001). The risk of AAE was relatively flat until 5 cm of aortic size, at which it began to increase rapidly (P for non-linearity <0.001). The mean annual growth rate was estimated to be 0.10 ± 0.01 cm/year. Ascending thoracic aortic aneurysms grew in a very slow manner, and aortic growth over 0.2 cm/year was rarely seen. Multivariable Cox regression identified aortic size [hazard ratio (HR): 1.78, 95% confidence interval (CI): 1.50-2.11, P < 0.001] and age (HR: 1.02, 95% CI: 1.00-1.05, P = 0.015) as significant independent risk factors for AAE. Interestingly, hyperlipidemia (HR: 0.46, 95% CI: 0.23-0.91, P = 0.025) was found to be a significant protective factor for AAE in univariable Cox regression.

CONCLUSION

An aortic size of 5 cm, rather than 5.5 cm, may be a more appropriate intervention criterion for prophylactic ATAA repair. Aortic growth may not be an applicable indicator for intervention.

2022 ACC/AHA guideline for the diagnosis and management of aortic disease: A report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Clinical Outcomes in Patients With Bicuspid Aortic Valves and Ascending Aorta ≥50 mm Under Surveillance

Background

Clinical outcomes of bicuspid aortic valve (BAV) patients with ascending aortic diameters ≥50 mm who are under surveillance are poorly defined.

Objectives

The purpose of this study was to assess clinical outcomes in BAV patients with ascending aorta ≥50 mm.

Methods

Multicenter retrospective cohort study of BAV adults with ascending aorta diameters ≥50 mm by transthoracic echocardiography (TTE). Patients were categorized into 50 to 54 mm and ≥55 mm groups. Clinical outcomes were aortic dissection (AoD), aorta surgery, surgical mortality, and all-cause death.

Results

Of 875 consecutive BAV patients (age 60 ± 13 years, 86% men, aortic diameter 51 mm [interquartile range (IQR): 50-53 mm]), 328 (37%) underwent early surgery ≤3 months from index TTE. Of the remaining 547 patients under surveillance, 496 had diameters 50 to 54 mm and 51 had diameters ≥55 mm and were collectively followed for 7.51 (IQR: 3.98-12.20) years. Of 496 patients with diameters 50 to 54 mm under surveillance, 266 (54%) underwent surgery 2.0 (IQR: 0.77-4.16) years from index TTE. AoD occurred in 9/496 (1.8%) patients for an incidence of 0.4 cases per 100 person-years, surgical mortality was 5/266 (1.9%); and ≥moderate aortic stenosis (but not aorta size) was associated with all-cause death, hazard ratio: 2.05 (95% CI: 1.32-3.20), P = 0.001. Conversely, in 547 total patients under surveillance (including 50-54 mm and ≥55 mm), both aorta size and ≥moderate aortic stenosis were associated with all-cause death (both P ≤ 0.027). AoD rate in patients ≥55 mm under surveillance was 5.9%.

Conclusions

In BAV patients with ascending aorta 50 to 54 mm under surveillance, AoD incidence is low and the overall rates of AoD and surgical mortality are similar, suggesting clinical equivalence between surgical and surveillance strategies. Conversely, patients with aortas ≥55 mm should undergo surgery. Aortic stenosis is associated with all-cause death in these patients.

A machine learning approach for predicting complications in descending and thoracoabdominal aortic aneurysms

OBJECTIVE

To use machine learning to predict rupture, dissection, and all-cause mortality for patients with descending and thoracoabdominal aortic aneurysms in an effort to improve on diameter-based surgical intervention criteria.

METHODS

Retrospective data from 1083 patients with descending aortic diameters 3.0 cm or greater were collected, with a mean follow-up time of 3.52 years and an average descending diameter of 4.13 cm. Six machine learning classifiers were trained using 44 variables to predict the occurrence of dissection, rupture, or all-cause mortality within 1, 2, or 5 years of initial patient encounter for a total of 54 (6 × 3 × 3) separate classifiers. Classifier performance was measured using area under the receiver operator curve.

RESULTS

Machine learning models achieved area under the receiver operator curves of 0.842 to 0.872 when predicting type B dissection, 0.847 to 0.856 when predicting type B dissection or rupture, and 0.820 to 0.845 when predicting type B dissection, rupture, or all-cause mortality. All models consistently outperformed descending aortic diameter across all end points (area under the receiver operator curve = 0.713-0.733). Feature importance inspection showed that other features beyond aortic diameter, such as a history of myocardial infarction, hypertension, and patient sex, play an important role in improving risk prediction.

CONCLUSIONS

This study provides surgeons with a more accurate, machine learning-based, risk-stratification metric to predict complications for patients with descending aortic aneurysms.

Regional biomechanical characterization of human ascending aortic aneurysms: Microstructure and biaxial mechanical response

The ascending thoracic aortic aneurysm (ATAA) is a permanent dilatation of the vessel with a high risk of adverse events, and shows heterogeneous properties. To investigate regional differences in the biomechanical properties of ATAAs, tissue samples were collected from 10 patients with tricuspid aortic valve phenotype and specimens from minor, anterior, major, and posterior regions were subjected to multi-ratio planar biaxial extension tests and second-harmonic generation (SHG) imaging. Using the data, parameters of a microstructure-motivated constitutive model were obtained considering fiber dispersion. SHG imaging showed disruptions in the organization of the layers. Structural and material parameters did not differ significantly between regions. The non-symmetric fiber dispersion model proposed by Holzapfel et al. [25] was used to fit the data. The mean angle of collagen fibers was negatively correlated between minor and anterior regions, and the parameter associated with collagen fiber stiffness was positively correlated between minor and major regions. Furthermore, correlations were found between the stiffness of the ground matrix and the mean fiber angle, and between the parameter associated with the collagen fiber stiffness and the out-of-plane dispersion parameter in the posterior and minor regions, respectively. The experimental data collected in this study contribute to the biomechanical data available in the literature on human ATAAs. Region-specific parameters for the constitutive models are fundamental to improve the current risk stratification strategies, which are mainly based on aortic size. Such investigations can facilitate the development of more advanced finite element models capable of capturing the regional heterogeneity of pathological tissues. STATEMENT OF SIGNIFICANCE: Tissue samples of human ascending thoracic aortic aneurysms (ATAA) were collected. Samples from four regions underwent multi-ratio planar biaxial extension tests and second-harmonic generation imaging. Region-specific parameters of a microstructure-motivated model considering fiber dispersion were obtained. Structural and material parameters did not differ significantly between regions, however, the mean fiber angle was negatively correlated between minor and anterior regions, and the parameter associated with collagen fiber stiffness was positively correlated between minor and major regions. Furthermore, correlations were found between the stiffness of the ground matrix and the mean fiber angle, and between the parameter associated with the collagen fiber stiffness and the out-of-plane dispersion parameter in the posterior and minor regions, respectively. This study provides a unique set of mechanical and structural data, supporting the microstructural influence on the tissue response. It may facilitate the development of better finite element models capable of capturing the regional tissue heterogeneity.

Aortic size distribution among normal, hypertension, bicuspid, and Marfan populations

Aims

Large-scale investigations on ascending aortic diameter, especially in the Asian population, are lacking. Furthermore, relevant evidence regarding the distribution of hypertension (HP), bicuspid aortic valve (BAV), and Marfan syndrome (MFS) is scarce. We aimed to examine the distribution of ascending aortic diameter in these populations in China.

Methods and results

The data of a total number of 698 795 individuals who underwent cardiac ultrasound were subjected to retrospective analysis. After screening, 647 087 individuals were included in the final analysis. In the normal population, the mean ascending aortic diameter was 28.1 ± 3.2 mm (27.2 ± 3.1 mm in women vs. 29.0 ± 3.1 mm in men) (P < 0.001). Aortic diameter increased gradually with age (P < 0.001). The prevalence of aortic dilation, aneurysm, and dissection in individuals with HP was 12.83%, 2.70%, and 4.77%, respectively. In individuals with MFS, the corresponding rates were 43.92%, 35.31%, and 26.11%. Notably, although BAV patients had high incidences of aortic dilation (37.00%) and aortic aneurysm (16.46%), the incidence of aortic dissection was relatively low (0.74%). Most cases of aortic dissection occurred at an aortic diameter of less than 55 mm. However, in the overall population, the incidence of aortic dissection significantly increased with the increase in the aortic diameter, revealing the existence of an 'aortic paradox'.

Conclusions

(i) The ascending diameter increases with age and is larger in men than in women; (ii) 'Aortic paradox' is explained; (iii) BAV bears a high rate of aortic dilation, but a low incidence of aortic dissection.

The Role of ADAMTS Proteoglycanases in Thoracic Aortic Disease

Thoracic aortic aneurysm and dissection (TAAD) are complex disease states with high morbidity and mortality that pose significant challenges to early diagnosis. Patients with an aneurysm are asymptomatic and typically present to the emergency department only after the development of a dissection. The extracellular matrix (ECM) plays a crucial role in regulating the aortic structure and function. The histopathologic hallmark termed medial degeneration is characterised by smooth muscle cell (SMC) loss, the degradation of elastic and collagen fibres and proteoglycan (PG) accumulation. Covalently attached to the protein core of PGs are a number of glycosaminoglycan chains, negatively charged molecules that provide flexibility, compressibility, and viscoelasticity to the aorta. PG pooling in the media can produce discontinuities in the aortic wall leading to increased local stress. The accumulation of PGs is likely due to an imbalance between their synthesis by SMCs and decreased proteolysis by A Disintegrin-like and Metalloproteinase with Thrombospondin motifs (ADAMTS) proteoglycanases in the ECM. Mouse models of TAAD indicated that these proteases exert a crucial, albeit complex and not fully elucidated, role in this disease. This has led to a mounting interest in utilising ADAMTS proteoglycanases as biomarkers of TAAD. In this review, we discuss the role of ADAMTSs in thoracic aortic disease and their potential use in facilitating the clinical diagnosis of TAAD and disease progression.

Ascending Aortic Volume: A Feasible Indicator for Ascending Aortic Aneurysm Elective Surgery?

Diameter-based criterion have been widely adopted for preventive surgery of ascending thoracic aortic aneurysm (ATAA). However, recent and growing evidence has shown that diameter-based methods may not be sufficient for identifying patients who are at risk of an ATAA. In this study, fluid-structure interaction (FSI) analysis was performed on one-hundred ATAA geometries reconstructed from clinical data to examine the relationship between hemodynamic conditions, ascending aortic volume (AAV), ascending aortic curvature, and aortic ratios measured from the reconstructed 3D models. The simulated hemodynamic and biomechanical parameters were compared among different groups of ATAA geometries classified based on AAV. The ATAAs with enlarged AAV showed significantly compromised hemodynamic conditions and higher mechanical wall stress. The maximum oscillatory shear index (OSI), particle residence time (PRT) and wall stress (WS) were significantly higher in enlarged ATAAs compared with controls (0.498 [0.497, 0.499] vs 0.499 [0.498, 0.499], p = 0.002, 312.847 [207.445, 519.391] vs 996.047 [640.644, 1573.140], p < 0.001, 769.680 [668.745, 879.795] vs 1072.000 [873.060, 1280.000] kPa, p < 0.001, respectively). Values were reported as median with interquartile range (IQR). AAV was also found to be more strongly correlated with these parameters compared to maximum diameter. The correlation coefficient between AAV and average WS was as high as 0.92 (p < 0.004), suggesting that AAV might be a feasible risk identifier for ATAAs. STATEMENT OF SIGNIFICANCE: Ascending thoracic aortic aneurysm is associated with the risk of dissection or rupture, creating life-threatening conditions. Current surgical intervention guidelines are purely diameter based. Recently, many studies proposed to incorporate other morphological parameters into the current clinical guidelines to better prevent severe adverse aortic events like rupture or dissection. The purpose of this study is to gain a better understanding of the relationship between morphological parameters and hemodynamic parameters in ascending aortic aneurysms using fluid-solid-interaction analysis on patient-specific geometries. Our results suggest that ascending aortic volume may be a better indicator for surgical intervention as it shows a stronger association with pathogenic hemodynamic conditions.

Postoperative imaging of thoracic aortic repairs

Imaging plays a crucial role in the postoperative monitoring of thoracic aortic repairs. With the development of multiple surgical techniques to repair the ascending aorta and aortic arch, it can be a daunting challenge for the radiologist to diagnose potential pathologies in this sea of various techniques, each with their own normal postoperative appearance and potential complications. In this paper, we will provide a comprehensive review of the postoperative imaging in the setting of thoracic aortic repairs, including the role of imaging, components of thoracic aortic repairs, the normal postoperative appearance, and potential complications.

Elective Thoracic Aortic Aneurysm Surgery: A Tertiary Center Experience

Background A thoracic aortic aneurysm (TAA) is a diseased expansion of the thoracic aorta. There is morbidity associated with a dilated aorta, as well as significant mortality. Open thoracic surgery is the fundamental management for proximal lesions, offering definitive treatment with excellent results. This study aimed to summarize preoperative data and operative outcomes of patients who underwent TAA repair at our institution. Methods Data were retrospectively collected from 234 patients that underwent elective open thoracic surgery at University Hospital Southampton for TAA disease, between 2015 and 2019. Demographics, clinical factors, surgical details, as well as outcome measures, were gathered. Results There were 166 males and 68 females, with an overall mean age of 66 years. The breakdown of operations comprised 105 aortic roots, 171 ascending aorta, 20 aortic arch, and 12 descending aorta cases. The mean follow-up was 370 days. 30-day mortality was 5.13%. Mortality was associated with female gender, aortic root surgery, and prosthetic valves. Mean aortic diameters at the time of surgery for the non-genetic aortopathy and genetic aortopathy groups were respectively 4.93cm and 4.63cm in the aortic root, 5.56cm and 4.88cm in the ascending aorta, 5.08cm and 3.87cm in the aortic arch, and 6.63cm and 5.50cm in the descending aorta. Conclusion Several factors are associated with complications and morbidity, which should be considered when discussing the risks of intervention with patients. There were no neuroprotective strategies that altered post-operative neurological function. Current practice in our unit fits in with current international guidance.

Novel biomarkers associated with thoracic aortic disease

BACKGROUND

Biomarkers might help to improve diagnosis, surveillance and risk stratification of thoracic aortic disease (TAD). We explored the association between a broad spectrum of cardiovascular biomarkers with clinical characteristics and thoracic aortic diameter in TAD patients.

METHODS

Venous blood-samples were obtained in 158 clinically stable TAD patients visiting our outpatient clinic (2017-2020). TAD was defined as a thoracic aortic diameter ≥ 40 mm, or genetic confirmation (hereditary TAD). The cardiovascular panel III of the Olink multiplex platform was used for batch analysis of 92 proteins. A comparison was made between biomarker levels in patients with and without previous aortic dissection and/or surgery, and with and without hereditary TAD. Linear regression analyses were applied to identify (relative, normalized) biomarker concentrations associated with the absolute thoracic aortic diameter (AD_max), and thoracic aortic diameter indexed for body surface area (ID_max).

RESULTS

Median age of study patients was 61.0 (IQR 50.3-68.8) years, 37.3% females. Mean AD_max and ID_max were 43.3 ± 5.4 mm and 21.3 ± 3.3 mm/m². After multivariable adjustment, Matrix Metalloproteinase-3 (MMP-3) and Insulin-like growth factor binding protein 2 (IGFBP-2) showed a significant positive association with AD_max and ID_max, respectively. Patients with previous aortic surgery/dissection had higher N-terminal-pro hormone BNP (NTproBNP) (median 3.67 [IQR 3.01-3.99] vs 2.84 [2.32-3.26], p ≤0.001). Patients with hereditary TAD had higher Trem-like transcript protein 2 (TLT-2) (median 4.64 [IQR 4.45-4.84]) than those with non-heriditary TAD (4.40 [4.17-4.64]; p = 0.00042).

CONCLUSIONS

Among a broad range of biomarkers, MMP-3 and IGFBP-2 were associated with disease severity in TAD patients. The pathophysiological pathways uncovered by these biomarkers, and their potential clinical use warrants further research.

Adventitial adaptive immune cells are associated with ascending aortic dilatation in patients with a bicuspid aortic valve

Background

Bicuspid aortic valve (BAV) is associated with ascending aorta aneurysms and dissections. Presently, genetic factors and pathological flow patterns are considered responsible for aneurysm formation in BAV while the exact role of inflammatory processes remains unknown.

Methods

In order to objectify inflammation, we employ a highly sensitive, quantitative immunohistochemistry approach. Whole slides of dissected, dilated and non-dilated ascending aortas from BAV patients were quantitatively analyzed.

Results

Dilated aortas show a 4-fold increase of lymphocytes and a 25-fold increase in B lymphocytes in the adventitia compared to non-dilated aortas. Tertiary lymphoid structures with B cell follicles and helper T cell expansion were identified in dilated and dissected aortas. Dilated aortas were associated with an increase in M1-like macrophages in the aorta media, in contrast the number of M2-like macrophages did not change significantly.

Conclusion

This study finds unexpected large numbers of immune cells in dilating aortas of BAV patients. These findings raise the question whether immune cells in BAV aortopathy are innocent bystanders or contribute to the deterioration of the aortic wall.

Influence of stent-induced vessel deformation on hemodynamic feature of bloodstream inside ICA aneurysms

One of the effective treatment options for intracranial aneurysms is stent-assisted coiling. Though, previous works have demonstrated that stent usage would result in the deformation of the local vasculature. The effect of simple stent on the blood hemodynamics is still uncertain. In this work, hemodynamic features of the blood stream on four different ICA aneurysm with/without interventional are investigated. To estimate the relative impacts of vessel deformation, four distinctive ICA aneurysm is simulated by the one-way FSI technique. Four hemodynamic factors of aneurysm blood velocity, wall pressure and WSS are compared in the peak systolic stage to disclose the impact of defamation by the stent in two conditions. The stent usage would decrease almost all of the mentioned parameters, except for OSI. Stenting reduces neck inflow rate, while the effect of interventional was not consistent among the aneurysms. The deformation of an aneurysm has a strong influence on the hemodynamics of an aneurysm. This outcome is ignored by most of the preceding investigations, which focused on the pre-interventional state for studying the relationship between hemodynamics and stents. Present results show that the application of stent without coiling would improve most hemodynamic factors, especially when the deformation of the aneurysm is high enough.

Ascending Aorta Dissection Before 5.5 cm Diameter; "It Wasn't Raining When Noah Built the Ark"

INTRODUCTION

The aim of this study was to compare mean maximum ascending aortic diameter at the time of acute aortic dissection with the current surgical threshold for elective ascending aortic operations on non-syndromic thoracic aortic aneurysms.

MATERIAL AND METHODS

All consecutive non-syndromic adult patients admitted for acute type A aortic dissection in a single tertiary centre were prospectively enrolled from April 2020 to March 2021. The primary endpoint was the difference between mean maximum aortic diameter at the time of dissection and the 5.5 cm threshold for elective repair. Secondary endpoints included 30-day/in-hospital mortality, aortic length and comparison with normal controls, length/height ratio index, "actual" preoperative Euroscore II and "predicted" Euroscore II if electively operated.

RESULTS

Among 31 patients ageing 67.3±12.03 years on average, mean maximum aortic diameter at the time of dissection was 5.13±0.66 cm, significantly lower than the guidelines-derived surgical threshold of 5.5 cm (p=0.004). Mean aortic length was 11±1.47 cm, also significantly longer compared normal controls reported in the literature (p<0.001). The 30-day/in-hospital mortality was 35.5%. Mean length/height ratio index was 6.18±0.76 cm/m. Finally, mean "actual" preoperative Euroscore II was 10.43±4.07 which was significantly higher than the 1.47±0.57 "predicted" Euroscore II (p<0.05).

CONCLUSIONS

The maximum aortic diameter at the time of acute type A aortic dissection of non-syndromic cases was significantly lower than the current recommendation for elective repair. Lowering of the current diameter-based surgical threshold of 5.5 cm may be profitable in terms of prevention, but further investigations should be undertaken. Length-based thresholds could also add to timely aortic dissection prevention.

Thoracic aortic aneurysm and atrial fibrillation: clinical associations with the risk of stroke from a global federated health network analysis

BACKGROUND

An association with aortic aneurysm has been reported among patients with atrial fibrillation (AF). The aims of this study were to investigate the prevalence of thoracic aorta aneurysm (TAA) among patients with AF and to assess whether the co-presence of TAA is associated with a higher risk of adverse clinical outcomes.

METHODS AND RESULTS

Using TriNetX, a global federated health research network of anonymised electronic medical records, all adult patients with AF, were categorised into two groups based on the presence of AF and TAA or AF alone. Between 1 January 2017 and 1 January 2019, 874,212 people aged ≥ 18 years with AF were identified. Of these 17,806 (2.04%) had a TAA. After propensity score matching (PSM), 17,805 patients were included in each of the two cohorts. During the 3 years of follow-up, 3079 (17.3%) AF patients with TAA and 2772 (15.6%) patients with AF alone, developed an ischemic stroke or transient ischemic attack (TIA). The risk of ischemic stroke/TIA was significantly higher in patients with AF and TAA (HR 1.09, 95% CI 1.04-1.15; log-rank p value < 0.001) The risk of major bleeding was higher in patients with AF and TAA (OR 1.07, 95% CI 1.01-1.14), but not significant in time-dependent analysis (HR 1.04, 95% CI 0.98-1.10; log-rank p value = 0.187), CONCLUSION: This retrospective analysis reports a clinical concomitance of the two medical conditions, and shows in a PSM analysis an increased risk of ischemic events in patients affected by TAA and AF compared to AF alone.

Ascending Aortic Aneurysms <4.5 cm for Nonsyndromic Adults: Very Slow Growth and Low Risk

BACKGROUND

 Current practice guidelines for patients with thoracic aortic aneurysms (TAAs) recommend 6 to 12-month intervals for surveillance imaging based on growth estimates of 0.10 to 0.42 cm/y gleaned from limited studies which included patients with thoracoabdominal aneurysms, known acute or chronic aortic dissection, and other syndromic and nonsyndromic high-risk conditions (TAA-HRC) associated with high-risk for adverse aortic events and death. Our objective was to determine TAA growth and event-free survival rates for patients with aortic root or midascending diameters <5.0 cm, and without thoracoabdominal aneurysms, acute or chronic aortic dissection or higher risk syndromic or nonsyndromic conditions (TAA-NoHRC).

METHODS

 A retrospective review of patient records and imaging studies were done. Aortic diameter measurements were all performed by the lead author.

RESULTS

 For 197 TAA-NoHRC found incidentally during chest imaging, with 616 chest imaging studies over 868 patient-years, the mean aortic root and midascending aortic growth rates were 0.018 and 0.022 cm/y, respectively. The growth rate was significantly lower for aneurysms initially measured at <4.5 cm versus ≥ 4.5 cm at both the aortic root (0.011 vs. 0.068 cm/y) and midascending aorta (0.013 vs. 0.043 cm/y). Survival free from adverse aortic events (dissection, rupture, and surgery) or death at 5 years was 99.5%.

CONCLUSION

 Adult TAA-NoHRC patients with initial aortic root and/or ascending aortic diameters <5.0 cm, and particularly <4.5 cm, have very low aortic growth, and adverse event rates which may permit longer intervals between surveillance imaging, up to 3 to 5 years, after initial (6-12 months) stability is documented.

Natural history of isolated abdominal aortic dissection: A prospective cohort study

Objectives

Isolated abdominal aortic dissection (IAAD) is extremely rare, with its optimal treatment and intervention timing remaining poorly understood. We aimed to study the natural history of IAAD and facilitate better clinical decision.

Methods

Consecutive patients admitted to our institution from January 2016 to April 2021 were enrolled and followed up prospectively. All-cause death was taken as the primary endpoint.

Results

A total of 68 patients with IAAD were included. The mean age at presentation was 61.2 ± 14.8 (Range: 26.0, 93.0) years and 55 (80.9%) were male. A total of 38 (55.9%) patients were treated conservatively, 27 (39.7%) received endovascular aneurysm repair (EVAR), and 3 (4.4%) underwent open surgery. After a mean follow-up of 2.4 years (Range: 0.1, 5.5), 9 (13.2%) patients died, 8 of whom (21.0%) were treated conservatively and 1 EVAR (3.7%). Compared with EVAR/open surgery, patient treated conservatively had a much worse survival (p = 0.043). There was no significant difference between different IAAD aortic sizes regarding mortality (p = 0.220). Patients with completely thrombosed false lumen fared improved survival rate, followed by partial thrombosis and patency, respectively, although not significantly (p = 0.190). No significant difference was observed between male and female concerning survival rate (p = 0.970). Patients without symptoms had a significantly improved survival (p = 0.048).

Conclusion

On the basis of patients' preference and surgeons' experience, a more aggressive treatment regimen for IAAD should be considered, with EVAR being the first choice, especially for those with persistent symptoms and patent false lumen, regardless of sex, age, or aortic size.

Assessment of shape-based features ability to predict the ascending aortic aneurysm growth

The current guidelines for the ascending aortic aneurysm (AsAA) treatment recommend surgery mainly according to the maximum diameter assessment. This criterion has already proven to be often inefficient in identifying patients at high risk of aneurysm growth and rupture. In this study, we propose a method to compute a set of local shape features that, in addition to the maximum diameter D, are intended to improve the classification performances for the ascending aortic aneurysm growth risk assessment. Apart from D, these are the ratio DCR between D and the length of the ascending aorta centerline, the ratio EILR between the length of the external and the internal lines and the tortuosity T. 50 patients with two 3D acquisitions at least 6 months apart were segmented and the growth rate (GR) with the shape features related to the first exam computed. The correlation between them has been investigated. After, the dataset was divided into two classes according to the growth rate value. We used six different classifiers with input data exclusively from the first exam to predict the class to which each patient belonged. A first classification was performed using only D and a second with all the shape features together. The performances have been evaluated by computing accuracy, sensitivity, specificity, area under the receiver operating characteristic curve (AUROC) and positive (negative) likelihood ratio LHR+ (LHR-). A positive correlation was observed between growth rate and DCR (r = 0.511, p = 1.3e-4) and between GR and EILR (r = 0.472, p = 2.7e-4). Overall, the classifiers based on the four metrics outperformed the same ones based only on D. Among the diameter-based classifiers, k-nearest neighbours (KNN) reported the best accuracy (86%), sensitivity (55.6%), AUROC (0.74), LHR+ (7.62) and LHR- (0.48). Concerning the classifiers based on the four shape features, we obtained the best accuracy (94%), sensitivity (66.7%), specificity (100%), AUROC (0.94), LHR+ (+∞) and LHR- (0.33) with support vector machine (SVM). This demonstrates how automatic shape features detection combined with risk classification criteria could be crucial in planning the follow-up of patients with ascending aortic aneurysm and in predicting the possible dangerous progression of the disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease: A Report of the American Heart Association/American College of Cardiology Joint Committee on Clinical Practice Guidelines

AIM

The "2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease" provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes).

METHODS

A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate.

STRUCTURE

Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Thoracic and Thoracoabdominal Aneurysms: Etiology, Epidemiology, and Natural History

Thoracic aortic aneurysms and thoracoabdominal aneurysms are often found incidentally. Complications include dissection or rupture. Most of the thoracic aortic aneurysms and thoracoabdominal aneurysms develop in patients with risk factors for atherosclerosis. Younger patients without significant cardiovascular risk factors may have a genetic basis and include syndromes such as Marfan, Ehlers-Danlos, and Loeys-Dietz and bicuspid aortic valve. Most thoracic aneurysms grow slowly over time and factors that accelerate growth rate include dissection, aneurysm size, bicuspid valve disease, and Marfan syndrome. Size cutoffs where complications occur determine when surgery or intervention should be considered.

Influence of the coiling porosity on the risk reduction of the cerebral aneurysm rupture: computational study

The formation and progress of cerebral aneurysm is highly associated with hemodynamic factors and blood flow feature. In this study, comprehensive efforts are done to investigate the blood hemodynamic effects on the creation and growth of the Internal Carotid Artery. The computational fluid dynamic method is used for the visualization of the bloodstream inside the aneurysm. Transitional, non-Newtonian and incompressible conditions are considered for solving the Navier-Stokes equation to achieve the high-risk region on the aneurysm wall. OSI and WSS of the aneurysm wall are compared within different blood flow stages. The effects of blood viscosity and coiling treatment on these factors are presented in this work. Our study shows that in male patients (HCT = 0.45), changing the porosity of coiling from 0.89 with 0.79 would decreases maximum OSI up to 75% (in maximum acceleration). However, this effect is limited to about 45% for female patients (HCT = 0.35).

Association of Thoracic Aortic Aneurysm Size With Long-term Patient Outcomes: The KP-TAA Study

Importance

The risk of adverse events from ascending thoracic aorta aneurysm (TAA) is poorly understood but drives clinical decision-making.

Objective

To evaluate the association of TAA size with outcomes in nonsyndromic patients in a large non-referral-based health care delivery system.

Design, Setting, and Participants

The Kaiser Permanente Thoracic Aortic Aneurysm (KP-TAA) cohort study was a retrospective cohort study at Kaiser Permanente Northern California, a fully integrated health care delivery system insuring and providing care for more than 4.5 million persons. Nonsyndromic patients from a regional TAA safety net tracking system were included. Imaging data including maximum TAA size were merged with electronic health record (EHR) and comprehensive death data to obtain demographic characteristics, comorbidities, medications, laboratory values, vital signs, and subsequent outcomes. Unadjusted rates were calculated and the association of TAA size with outcomes was evaluated in multivariable competing risk models that categorized TAA size as a baseline and time-updated variable and accounted for potential confounders. Data were analyzed from January 2018 to August 2021.

Exposures

TAA size.

Main Outcomes and Measures

Aortic dissection (AD), all-cause death, and elective aortic surgery.

Results

Of 6372 patients with TAA identified between 2000 and 2016 (mean [SD] age, 68.6 [13.0] years; 2050 female individuals [32.2%] and 4322 male individuals [67.8%]), mean (SD) initial TAA size was 4.4 (0.5) cm (828 individuals [13.0% of cohort] had initial TAA size 5.0 cm or larger and 280 [4.4%] 5.5 cm or larger). Rates of AD were low across a mean (SD) 3.7 (2.5) years of follow-up (44 individuals [0.7% of cohort]; incidence 0.22 events per 100 person-years). Larger initial aortic size was associated with higher risk of AD and all-cause death in multivariable models, with an inflection point in risk at 6.0 cm. Estimated adjusted risks of AD within 5 years were 0.3% (95% CI, 0.3-0.7), 0.6% (95% CI, 0.4-1.3), 1.5% (95% CI, 1.2-3.9), 3.6% (95% CI, 1.8-12.8), and 10.5% (95% CI, 2.7-44.3) in patients with TAA size of 4.0 to 4.4 cm, 4.5 to 4.9 cm, 5.0 to 5.4 cm, 5.5 to 5.9 cm, and 6.0 cm or larger, respectively, in time-updated models. Rates of the composite outcome of AD and all-cause death were higher than for AD alone, but a similar inflection point for increased risk was observed at 6.0 cm.

Conclusions and Relevance

In a large sociodemographically diverse cohort of patients with TAA, absolute risk of aortic dissection was low but increased with larger aortic sizes after adjustment for potential confounders and competing risks. Our data support current consensus guidelines recommending prophylactic surgery in nonsyndromic individuals with TAA at a 5.5-cm threshold.

Ascending aortic geometry and its relationship to the biomechanical properties of aortic tissue

Objective

The objective of this study was to evaluate the relationship between ascending aortic geometry and biomechanical properties.

Methods

Preoperative computed tomography scans from ascending aortic aneurysm patients were analyzed using a center line technique (n = 68). Aortic length was measured from annulus to innominate artery, and maximal diameter from this segment was recorded. Biaxial tensile testing of excised tissue was performed to derive biomechanical parameters energy loss (efficiency in performing the Windkessel function) and modulus of elasticity (stiffness). Delamination testing (simulation of dissection) was performed to derive delamination strength (strength between tissue layers).

Results

Aortic diameter weakly correlated with energy loss (r ² = 0.10; P < .01), but not with modulus of elasticity (P = .13) or delamination strength (P = .36). Aortic length was not associated with energy loss (P = .87), modulus of elasticity (P = .13) or delamination strength (P = .90). Using current diameter guidelines, aortas >55 mm (n = 33) demonstrated higher energy loss than those <55 mm (n = 35; P = .05), but no difference in modulus of elasticity (P = .25) or delamination strength (P = .89). A length cutoff of 110 mm was proposed as an indication for repair. Aortas >110 mm (n = 37) did not exhibit a difference in energy loss (P = .40), modulus of elasticity (P = .69), or delamination strength (P = .68) compared with aortas <110 mm (n = 31). Aortas above diameter and length thresholds (n = 21) showed no difference in energy loss (P = .35), modulus of elasticity (P = .55), or delamination strength (P = .61) compared with smaller aortas (n = 47).

Conclusions

Aortic geometry poorly reflects the mechanical properties of aortic tissue. Weak association between energy loss and diameter supports intervention at larger diameters. Further research into markers that better capture aortic biomechanics is needed.

Endovascular repair of a ruptured, extremely tortuous, descending thoracic aorta aneurysm with aortic coarctation

We have presented a case of a ruptured descending aortic aneurysm that was accompanied by extreme tortuosity and a pseudocoarctation at the level of the ligamentum arteriosum. We performed successful endovascular repair, covering the left subclavian artery, using a transapical-to-femoral artery (through-and-through) guidewire technique to overcome the tortuosity, with the option to perform balloon angioplasty in the case of an increased gradient over the coarctation. In the present case report, we have underlined the role of close collaborations with aortic expertise centers.

Thoracoabdominal Aortic Disease and Repair: JACC Focus Seminar, Part 3

Thoracoabdominal aortic disease is a rare but life-threatening condition that requires expert multidisciplinary collaborative management. Intervention is indicated in patients with symptomatic aneurysms or when an aneurysm reaches a certain threshold of diameter or rate of expansion. The strategies for spinal cord and end-organ protection have evolved over several decades, resulting in improved outcomes after repair. Open repair, although invasive, provides definitive and durable repair. Endovascular approaches are rapidly evolving, and the results with fenestrated and branched endografts are promising. Both open repair and endovascular repair require highly specialized expertise, and outcomes are best when repair is undertaken in an elective setting by a dedicated team. Patients with degenerative thoracoabdominal aortic aneurysms and chronic dissections should be followed up closely and referred for elective repair when indicated.

Performance of a deep learning tool to detect missed aortic dilatation in a large chest CT cohort

Purpose

Thoracic aortic (TA) dilatation (TAD) is a risk factor for acute aortic syndrome and must therefore be reported in every CT report. However, the complex anatomy of the thoracic aorta impedes TAD detection. We investigated the performance of a deep learning (DL) prototype as a secondary reading tool built to measure TA diameters in a large-scale cohort.

Material and methods

Consecutive contrast-enhanced (CE) and non-CE chest CT exams with “normal” TA diameters according to their radiology reports were included. The DL-prototype (AIRad, Siemens Healthineers, Germany) measured the TA at nine locations according to AHA guidelines. Dilatation was defined as &gt;45 mm at aortic sinus, sinotubular junction (STJ), ascending aorta (AA) and proximal arch and &gt;40 mm from mid arch to abdominal aorta. A cardiovascular radiologist reviewed all cases with TAD according to AIRad. Multivariable logistic regression (MLR) was used to identify factors (demographics and scan parameters) associated with TAD classification by AIRad.

Results

18,243 CT scans (45.7% female) were successfully analyzed by AIRad. Mean age was 62.3 ± 15.9 years and 12,092 (66.3%) were CE scans. AIRad confirmed normal diameters in 17,239 exams (94.5%) and reported TAD in 1,004/18,243 exams (5.5%). Review confirmed TAD classification in 452/1,004 exams (45.0%, 2.5% total), 552 cases were false-positive but identification was easily possible using visual outputs by AIRad. MLR revealed that the following factors were significantly associated with correct TAD classification by AIRad: TAD reported at AA [odds ratio (OR): 1.12, p &lt; 0.001] and STJ (OR: 1.09, p = 0.002), TAD found at &gt;1 location (OR: 1.42, p = 0.008), in CE exams (OR: 2.1–3.1, p &lt; 0.05), men (OR: 2.4, p = 0.003) and patients presenting with higher BMI (OR: 1.05, p = 0.01). Overall, 17,691/18,243 (97.0%) exams were correctly classified.

Conclusions

AIRad correctly assessed the presence or absence of TAD in 17,691 exams (97%), including 452 cases with previously missed TAD independent from contrast protocol. These findings suggest its usefulness as a secondary reading tool by improving report quality and efficiency.

Aortic Root Aneurysm in an Extreme Athlete

Aortic root aneurysms require close clinical monitoring due to the risk of dissection or rupture. While patients usually remain asymptomatic, it can occasionally be detected on physical examination as a diastolic murmur, which can be further confirmed with diagnostic imaging. The vast majority of aneurysms are found in patients with congenital or acquired conditions that compromise vascular integrity. Here, we present a case of an athletic, healthy appearing 54-year-old who was incidentally found to have a severely enlarged aneurysm requiring urgent surgical intervention.

On strain-based rupture criterion for ascending aortic aneurysm: the role of fiber waviness

We propose a new approach for constructing strain-based rupture criterion for ascending thoracic aortic aneurysm. The rupture metric is formulated using an effective strain, which is a measure of net strain that the collagen bundles experience after fiber uncrimping. The effective strain is a function of the total strain and the waviness properties of the collagen fibers. In the present work, the waviness properties are obtained from fitting biaxial response data to constitutive models that explicitly consider the collagen waviness and fiber recruitment. Inflation test data from 10 ascending thoracic aortic aneurysm specimens are analyzed. For each specimen, tension-strain data at ∼2300 material points are garnered. The effective strain fields in the configuration immediately before rupture are computed. It is found that the hotspots of the effective strain match the rupture sites very well in all 10 samples. More importantly, the values of effective strain at the hotsopts are closely clustered around 0.1, in contrast to a much wider distribution of the total strain. The study underscores the importance of considering the fiber recruitment in formulating strain-based rupture metric, and suggests that ϵ¯≈0.1, where ϵ¯ is the effective strain metric defined in this work, can be considered as a criterion for assessing the imminent rupture risk of ascending aortic aneurysms.

Toward standard abbreviations and acronyms for use in articles on aortic disease

Objectives

Academic medical literature is fraught with complex article-specific acronyms and abbreviations that can impair communication and make reading arduous. Our goal is to ease frustration with bespoke, inconsistent, and variable sets of abbreviations that currently exist for common aorta-related terminology (eg, anatomy, imaging, disease, and therapy). We hope to ease reading and improve communication in the aortic sphere of cardiovascular literature.

Methods

We reviewed a total of 205 published references related to aortic disease, including a systematic review of aorta-related articles in the Journal of Thoracic and Cardiovascular Surgery from the years 2020 and 2021. The array of variable definitions, abbreviations, and acronyms encountered in different papers that refer to the same terminology was striking, revealing that there were few standardized abbreviations in the aortic literature. We cataloged these terms, their associated abbreviations, and their frequency of use, and compiled a list of proposed standard abbreviations for commonly used terms that could be implemented uniformly in articles written about aortic diseases.

Results

We present suggested acronyms and abbreviations for common terminology related to the aorta. It is anticipated that this standard list will evolve over time as the literature and technology of the field grows and develops.

Conclusions

A proposed standard set of acronyms and abbreviations for aorta-related terminology is provided that, if found useful, could be implemented broadly in the aortic literature.

Quantitative normal values of helical flow, flow jets and wall shear stress of healthy volunteers in the ascending aorta

OBJECTIVES

4D flow MRI enables quantitative assessment of helical flow. We sought to generate normal values and elucidate changes of helical flow (duration, volume, length, velocities and rotational direction) and flow jet (displacement, flow angle) as well as wall shear stress (WSS).

METHODS

We assessed the temporal helical existence (TH_EX), maximum helical volume (HV_max), accumulated helical volume (HV_acc), accumulated helical volume length (HVL_acc), maximum forward velocity (maxV_for), maximum circumferential velocity (maxV_circ), rotational direction (RD) and maximum wall shear stress (WSS) as reported elsewhere using the software tool Bloodline in 86 healthy volunteers (46 females, mean age 41 ± 13 years).

RESULTS

WSS decreased by 42.1% and maxV_for by 55.7% across age. There was no link between age and gender regarding the other parameters.

CONCLUSION

This study provides age-dependent normal values regarding WSS and maxV_for and age- and gender-independent normal values regarding TH_EX, HV_max, HV_acc, HVL_acc, RD and _maxV_circ.

KEY POINTS

• 4D flow provides numerous new parameters; therefore, normal values are mandatory. • Wall shear stress decreases over age. • Maximum helical forward velocity decreases over age.

Can We Better Differentiate Type A Dissections: Evaluating the Role of Aortic Ratios

OBJECTIVES

Type A aortic dissection (ATAAD) is hypothesised as a progression of aneurysmal dilation, but 60% of patients in the International Registry of Acute Aortic Dissection (iRAD) registry had a maximum aortic diameter (MAD)<55 mm. We aim to demonstrate that size ratios and aortic wall stress, assessed using a simplified markers, are unique to aortic patients who have had adverse events (ATAAD) compared to those who have not (thoracic aortic aneurysm [TAA]).

METHODS

A retrospective cohort analysis of patients who underwent aortic intervention at Waikato Hospital, New Zealand between 2015-2020, comparing dissection (ATAAD) to TAA patients. MAD; ratio of MAD to standardised-points within the aorta; and MAD-to-height collected from computed tomography (CT)-scans of all patients was undertaken. Receiver operating characteristic (ROC)-analysis to determine cut-off point for each marker was undertaken together with multivariable logistic regression comparing both cohorts, cross-validated by propensity-score matched analysis.

RESULTS

Cohort of 215 patients, 78 (36.3%) ATAAD and 137 (63.7%) TAA; median age at intervention 63.3 years, 52 (24.2%) females, both cohorts matched for size. Using the entire cohort, the MAD: sinus of Valsalva (SoV) ratio>1.06 (cut-off value) had 4.5-times greater association with ATAAD (95%CI 1.46-13.8) and a 0.1-unit increased conferred 1.45-times greater association with ATAAD (95%CI 1.00-2.08). MAD>55 mm only seen in 33.3% of ATAAD (n=26/78), and not associated with ATAAD (OR 1.88, 95%CI 0.64-5.51). Compared to MAD, MAD:SoV ratio had greater sensitivity (33% vs 73%), lower number-needed-to-treat (17.9 vs 2.7) and superior discrimination (area under the curve [AUC] 0.54 vs 0.71). Findings were consistent with propensity score matched analysis.

CONCLUSIONS

MAD:SoV ratio significantly correlates with ATAAD (4.5 times), with superior sensitivity, discrimination, and attributable-risk-percentage compared to MAD alone.

Natural history of bicuspid aortic valves and ascending aortic aneurysms: Aortic center experience

BACKGROUND AND AIM

The American Association of Thoracic Surgery published guidelines in 2018 encouraging regular surveillance rather than surgical intervention for ascending aortic aneurysms under 5.5 cm in both bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) patients. Since then, there have been limited studies reporting outcomes, especially by valve type. We aimed to analyze clinical outcomes including survival and aortic events in a cohort of BAV and TAV patients with ascending aortic aneurisms followed conservatively with routine computerized tomography  (CT) surveillance per current guidelines.

METHODS

We followed 188 patients in our clinic between 2016 and 2019; 147 had two or more CT scans which allowed measurement of aortic growth. Echocardiogram data was evaluated for each patient. We identified similar cohorts of BAV (n = 32) and TAV (n = 64) patients matched by age, sex, hypertension, smoking history, family history of aortic disease, coronary artery disease, and hyperlipidemia. Univariate and multivariate analyses of the unmatched cohorts were performed.

RESULTS

The mean aneurysm size was 4.3 ± 0.58 cm with 95% confidence interval (3.14, 5.46). This did not differ between BAV and TAV patients, nor did aneurysm growth rates. Overall adverse event rate (dissection, rupture, and death) was low for the entire cohort (BAV group, 3% and TAV group, 3.5%). Survival at 10 years for the entire cohort was 90 ± 32%.

CONCLUSIONS

Regardless of aortic valve type, there was a similar natural history and low adverse event rate. In the absence of risk factors, conservative management can be accomplished with minimal risk to the patient.

The prevalence of thoracic aorta aneurysm as an important cardiovascular disease in the general population

BACKGROUND

The aorta is the largest and main artery in the body. The enlargement of the aortic diameter known as ectasia results in aneurysm. Thoracic aorta aneurysm can involve one or more segments of the aorta. Non-invasive imaging techniques play an important role in identifying patients, estimating maximal aneurysm diameter, following up patients, and detecting complications. So, this study was performed to estimate the prevalence of ascending thoracic aorta aneurysm in the general population of Iran.

METHODS

People with an abnormal aortic size (˃ 36 mm) were enrolled and subjected to diagnostic tests, and related risk factors were assessed.

RESULT

Of the 3400 people examined, 410 (12%) had abnormal aorta sizes, and 42 (1.2%) had ascending aorta aneurysm. Out of the 410 patients with elevated aorta size, 235 (57%) were males, and 175 (43%) were females. Overall, 229 patients (56%) had hypertension, and 255 (62%) were over 60 years old.

CONCLUSION

In this study, we showed that the prevalence of ascending aorta aneurysm in the general population of Iran was about 1.2%. Ascending aorta aneurysm is a threatening pathology of the aorta. The high prevalence of hypertension may explain the high incidence of aneurysm in our studied population. Therefore, it is necessary to implement an accurate screening plan to identify patients with hypertension and provide appropriate treatment and adequate follow up to patients. Patients with ascending aorta aneurysm are also recommended to modify their lifestyles.

A rare case of thoracic-abdominal aortic aneurysm in conjunction with bilateral superficial femoral artery occlusion, documented with computed tomography angiography

Aneurysms represent bulging of the weakened blood vessel area, as a result of cystic medial degeneration. Aneurysms chance of rupturing increases over time, resulting in bleeding and death. Therefore, patients with aortic aneurysms require frequent monitoring with magnetic resonance and computed tomography angiography, as well as undergoing open repair surgery and endovascular aneurysm repair.

We present a case of ruptured thoracic aortic aneurysm in conjunction with bilateral superficial femoral occlusion, as incidental findings in Covid-19 positive patient.

The patient, a 62-years-old female, presented with cough, shortness of breath, fever and leg claudication. Doppler ultrasonography of the lower limbs was conducted to rule out thromboembolism, revealing bilateral superficial femoral arteries occlusion. The patient was administered high doses of parenteral anticoagulants.

Hemoptysis ensued, prompting an MSCT scan, that showed right pleural effusion, atelectasis, and right active perihilar infiltrates with inter-lobar pleurisy. Due to inflammatory changes on the lung parenchyma, the patient got tested for Sars-Cov-2, and resulted positive.

Contrast-enhanced MSCT also revealed thoracic-abdominal aortic aneurysm with its highest diameter measuring 10 cm, and massive per-aortal thrombus and/or hematoma of 5 cm, which was further ruptured and patient died untreated in the fourth day of hospitalization.

Questions arise whether Covid-19 was the primary cause of bilateral superficial femoral artery occlusion and whether high doses of parenteral anticoagulants were the primary cause of thoracic aortic aneurysm rupture.

Thus, a careful balance must be made between the detrimental and protective contributions of anticoagulants in the patients presenting with Covid-19 and thoracic-abdominal aortic aneurysm.