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

A deep learning algorithm for the detection of aortic dissection on non-contrast-enhanced computed tomography via the identification and segmentation of the true and false lumens of the aorta

Background

Aortic dissection is a life-threatening clinical emergency, but it is often missed and misdiagnosed due to the limitations of diagnostic technology. In this study, we developed a deep learning-based algorithm for identifying the true and false lumens in the aorta on non-contrast-enhanced computed tomography (NCE-CT) scans and to ascertain the presence of aortic dissection. Additionally, we compared the diagnostic performance of this algorithm with that of radiologists in detecting aortic dissection.

Methods

We included 320 patients with suspected acute aortic syndrome from three centers (Beijing Anzhen Hospital Affiliated to Capital Medical University, Fujian Provincial Hospital, and Xiangya Hospital of Central South University) between May 2020 and May 2022 in this retrospective study. All patients underwent simultaneous NCE-CT and contrast-enhanced CT (CE-CT). The cohort comprised 160 patients with aortic dissection and 160 without aortic dissection. A deep learning algorithm, three-dimensional (3D) full-resolution U-Net, was continuously trained and refined to segment the true and false lumens of the aorta to determine the presence of aortic dissection. The algorithm's efficacy in detecting dissections was evaluated using the receiver operating characteristic (ROC) curve, including the area under the curve (AUC), sensitivity, and specificity. Furthermore, a comparative analysis of the diagnostic capabilities between our algorithm and three radiologists was conducted.

Results

In diagnosing aortic dissection using NCE-CT images, the developed algorithm demonstrated an accuracy of 93.8% [95% confidence interval (CI): 89.8-98.3%], a sensitivity of 91.6% (95% CI: 86.7-95.8%), and a specificity of 95.6% (95% CI: 91.2-99.3%). In contrast, the radiologists achieved an accuracy of 88.8% (95% CI: 83.5-94.1%), a sensitivity of 90.6% (95% CI: 83.5-94.1%), and a specificity of 94.1% (95% CI: 72.9-97.6%). There was no significant difference between the algorithm's performance and radiologists' mean performance in accuracy, sensitivity, or specificity (P>0.05).

Conclusions

The algorithm proficiently segments the true and false lumens in aortic NCE-CT images, exhibiting diagnostic capabilities comparable to those of radiologists in detecting aortic dissection. This suggests that the algorithm could reduce misdiagnoses in clinical practice, thereby enhancing patient care.

Statin suppresses the development of excessive intimal proliferation in a Kawasaki disease mouse model

Kawasaki disease (KD) causes vascular injury and lifelong remodeling. Excessive intimal proliferation has been observed, resulting in coronary artery lesions (CALs). However, the mechanisms underlying vascular remodeling in CAL and statin treatment have not been comprehensively elucidated. This study aimed to investigate the effects of statins on vascular remodeling using a KD mouse model. Candida albicans water-soluble substance (CAWS) was intraperitoneally injected in 5-week-old male apolipoprotein-E-deficient mice. They were categorized as follows (n = 4): control, CAWS, CAWS+statin, and late-statin groups. The mice were euthanized at 6 or 10 weeks after injection. Statins (atorvastatin) were initiated after CAWS injection, except for the late-statin group, for which statins were internally administered 6 weeks after injection. Elastica van Gieson staining and immunostaining were performed for evaluation. Statins substantially suppressed the marked neointimal hyperplasia induced by CAWS. Additionally, CAWS induced TGFβ receptor II and MAC-2 expression around the coronary arteries, which was suppressed by the statins. KD-like vasculitis might promote the formation of aneurysm by destroying elastic laminae and inducing vascular stenosis by neointimal proliferation. The anti-inflammatory effects of statins might inhibit neointimal proliferation. Therefore, statin therapy might be effective in adult patients with KD with CAL by inhibiting vascular remodeling.

Importance of surgeon's experience in practicing valve-sparing aortic root replacement

Background

Valve-sparing root replacement (VSRR) requires a unique skill set. This study aimed to examine the influence of surgeon's procedural volume on outcomes of VSRR.

Methods

This retrospective study included 1697 patients from 2 large, high-volume aortic centers who underwent aortic root replacement (ARR) between 2004 and 2021 and were potentially eligible for VSRR. Surgeons were classified as performing <5 ARRs or ≥5 ARRs annually. Multivariable logistic regression was used to examine the independent association of surgeon volume and the decision to perform VSRR. Inverse probability treatment weighting (IPTW) was used to match patients who were operated on by <5 ARR surgeons or ≥5 ARR surgeons and compare long-term survival probability. Cumulative incidence curves with mortality as a competing risk were plotted to compare the rate of aortic valve reoperation.

Results

Of 1697 patients who met the study inclusion criteria, 944 underwent composite-valve conduit ARR and 753 underwent VSRR. The median age of the cohort was 57 years (interquartile range, 45-66 years), and 268 (15.8%) were female. Aortic insufficiency was present in 1105 patients (65.1%), and 200 of the procedures (11.8%) were reoperations. The indication for surgery was aneurysm in 1496 patients (88.2%) and dissection in 201 (11.8%). Among the 743 patients who underwent VSRR, 691 (92%) were operated on by ≥ 5 ARR surgeons and 62 (8%) were operated on by <5 ARR surgeons. In multivariable logistic regression, ≥5 ARRs (odds ratio, 3.33; 95% confidence interval, 2.34-4.73; P < .001) was associated with VSRR as the procedure of choice. Following IPTW, there was no significant difference between <5 ARR and ≥5 ARR surgeons in survival probability after VSRR (P = .59) or in the rate of aortic valve reoperation (P = .60).

Conclusions

In the setting of a high-volume aortic center, patients who undergo ARR are less likely to receive VSRR if operated on by a <5 ARR surgeon; however, VSRR may be safely performed by <5 ARR surgeons.

Wall shear stress measured with 4D flow CMR correlates with biomarkers of inflammation and collagen synthesis in mild-to-moderate ascending aortic dilation and tricuspid aortic valves

AIMS

Understanding the mechanisms underlying ascending aortic dilation is imperative for refined risk stratification of these patients, particularly among incidentally identified patients, most commonly presenting with tricuspid valves. The aim of this study was to explore associations between ascending aortic haemodynamics, assessed using four-dimensional flow cardiovascular magnetic resonance imaging (4D flow CMR), and circulating biomarkers in aortic dilation.

METHODS AND RESULTS

Forty-seven cases with aortic dilation (diameter ≥ 40 mm) and 50 sex-and age-matched controls (diameter < 40 mm), all with tricuspid aortic valves, underwent 4D flow CMR and venous blood sampling. Associations between flow displacement, wall shear stress (WSS), and oscillatory shear index in the ascending aorta derived from 4D flow CMR, and biomarkers including interleukin-6, collagen type I α1 chain, metalloproteinases (MMPs), and inhibitors of MMPs derived from blood plasma, were investigated. Cases with dilation exhibited lower peak systolic WSS, higher flow displacement, and higher mean oscillatory shear index compared with controls without dilation. No significant differences in biomarkers were observed between the groups. Correlations between haemodynamics and biomarkers were observed, particularly between maximum time-averaged WSS and interleukin-6 (r = 0.539, P < 0.001), and maximum oscillatory shear index and collagen type I α1 chain (r = -0.575, P < 0.001 in cases).

CONCLUSION

Significant associations were discovered between 4D flow CMR derived whole-cardiac cycle WSS and circulating biomarkers representing inflammation and collagen synthesis, suggesting an intricate interplay between haemodynamics and the processes of inflammation and collagen synthesis in patients with early aortic dilation and tricuspid aortic valves.

Outcomes of thoracic endovascular aortic repair with fenestrated surgeon-modified stent-grafts for type B aortic dissection involving the aortic arch: a multicenter retrospective study

Background

Thoracic endovascular aortic repair (TEVAR) with fenestrated surgeon-modified stent-grafts (f-SMSGs) is becoming an option for treating type B aortic dissection (TBAD) involving the aortic arch. This study aimed to evaluate the outcomes of this technique.

Methods

A retrospective multicenter study was conducted, involving consecutive patients from three medical centers in China who underwent TEVAR with f-SMSG for TBAD. A new technique called "Lu's direction-turnover technique" was employed to align the fenestrations with supra-aortic vessels.

Results

From March 2016 to January 2020, 117 patients diagnosed with TBAD were deemed eligible for inclusion. The technical success rate was 94% (n=110). The estimated 30-day survival rate was 97.4% [95% confidence interval (CI): 94.5% to 100.0%], with freedom from re-intervention estimated at 95.7% (95% CI: 92.0% to 99.4%). The median follow-up period was 27 months (interquartile range, 19 to 35 months). The estimated survival rate at 27 months was 94.9% (95% CI: 90.8% to 98.9%) and the rate of freedom from re-intervention was 91.5% (95% CI: 86.3% to 96.6%). Cases of retrograde type A aortic dissection, stroke and endoleaks were documented. Five cases of retrograde type A aortic dissection were documented, with three occurring within 30 days and one during the follow-up. Four cases of stroke were recorded, with one occurring within 30 days and three during the follow-up. Furthermore, eleven cases of endoleaks were recorded, with one occurring within 30 days and ten during the follow-up.

Conclusions

Clinically acceptable technical success and prognosis were observed in a cohort with TEVAR with f-SMSG for the treatment of TBAD involving the aortic arch, which necessitated revascularization of the supra-aortic vessels. Further comparative studies are required to validate the benefits of this approach.

Assessment of abnormal transvalvular flow and wall shear stress direction for pediatric/young adults with bicuspid aortic valve: A cross-sectional four-dimensional flow study

BACKGROUND

Aortic dilation is seen in pediatric/young adult patients with bicuspid aortic valve (BAV), and hemodynamic markers to predict aortic dilation are necessary for monitoring. Although promising hemodynamic metrics, such as abnormal wall shear stress (WSS) magnitude, have been proposed for adult BAV patients using four-dimensional (4D) flow cardiovascular magnetic resonance, those for pediatric BAV patients have less frequently been reported, partly due to scarcity of data to define normal WSS range. To circumvent this challenge, this study aims to investigate if a recently proposed 4D flow-based hemodynamic measurement, abnormal flow directionality, is associated with aortic dilation in pediatric/young adult BAV patients.

METHODS

4D flow scans for BAV patients (<20 years old) and age-matched controls were retrospectively enrolled. Static segmentation for the aorta and pulmonary arteries was obtained to quantify peak systolic hemodynamics and diameters in the proximal aorta. In addition to peak velocity, WSS, vorticity, helicity, and viscous energy loss, direction of aortic velocity and WSS in BAV patients were compared with that of control atlas using registration technique; angle differences of >60 deg and >120 deg were defined as moderately and severely abnormal, respectively. The association between the obtained metrics and normalized diameters (Z-scores) was evaluated at the sinotubular junction, mid-ascending aorta, and distal ascending aorta.

RESULTS

Fifty-three BAV patients, including 18 with history of repaired aortic coarctation, and 17 controls were enrolled. Correlation between moderately abnormal velocity/WSS direction and aortic Z-scores was moderate to strong at the sinotubular junction and mid-ascending aorta (R = 0.62-0.81; p < 0.001) while conventional measurements exhibited weaker correlation (|R| = 0.003-0.47, p = 0.009-0.99) in all subdomains. Multivariable regression analysis found moderately abnormal velocity direction and existence of aortic regurgitation (only for isolated BAV group) were independently associated with mid-ascending aortic Z-scores.

CONCLUSION

Abnormal velocity and WSS directionality in the proximal aorta were strongly associated with aortic Z-scores in pediatric/young adult BAV patients.

Elective root replacement increases the risk of type B dissection in patients with Marfan syndrome

OBJECTIVE

Marfan syndrome is a genetic disorder with increased risk of aortic dissection. Currently, type A aortic dissection risk is mitigated by aortic root replacement with Dacron. It is unclear if root replacement increases the risk of distal aortic disease given the noncompliant nature of Dacron.

METHODS

All adult patients with a diagnosis of Marfan syndrome at a single academic center, excluding those with history of dissection or concomitant arch repair, were studied (n = 322). Student t test or Wilcoxon Mann-Whitney test was used for continuous variables; chi-square or Fisher exact test was used for categorical variables. Propensity matching used age, sex, hypertension, race, body mass index, family history of Marfan syndrome, and genetic mutational class. Differences in freedom from type B aortic dissection were determined using the log-rank test.

RESULTS

A total of 124 patients underwent root replacement compared with 198 patients with no prior aortic surgery. Median follow-up time was 9.90 years. Male sex, weight, and hypertension prevalence were higher in the root replacement group (P < .05). Distribution of fibrillin-1 mutations was homogenous (P > .9). Type B aortic dissection frequency in the root replacement group was higher (21% [n = 20] vs 4.2% [n = 4], P < .001). Aortic-related mortality was higher in the root replacement group (11% [n = 14] vs 3.5% [n = 7], P < .01). Distal aortic intervention frequency was higher in the root replacement group (P = .009).

CONCLUSIONS

Patients with Marfan syndrome who undergo elective aortic root replacement appear to have a higher incidence of subsequent type B aortic dissection, independent of other risk factors. Careful consideration must be made to the management of the distal aorta in patients with Marfan syndrome who undergo root replacement.

Clinical effectiveness of genetic testing guidelines in patients with thoracic aortic aneurysms

OBJECTIVE

To analyze the effectiveness of the current genetic testing guidelines for patients with thoracic aortic aneurysms.

METHODS

We evaluated genetic tests for thoracic aortic disease (TAD) from 2012 to 2023 in patients aged 18 and older with a thoracic aorta diameter greater than 4 cm. Mutation rates were compared by American College of Cardiology/American Heart Association testing criteria met by patients: age younger than 60 years, syndromic features of connective tissue diseases (CTDs), family history, or none. Results were classified as pathogenic, variants of uncertain significance (VUS), or negative. Genes tested were analyzed in 2 categories: primary (strongly associated with heritable diseases) or secondary (less strongly associated).

RESULTS

In total, 1034 patients were included: 42.4% aged younger than 60 years, 19.1% with syndromic features of CTD, 41.8% with family history, and 30.7% meeting no criteria. Overall, 3.97% had pathogenic mutations, and 27.27% had VUS. Mutation rates were greatest in patients with syndromic features of CTD (13.2%), followed by patients aged younger than 60 years (5.48%), with a family history (4.63%), and with no criteria met (2.21%). Primary genes had pathogenic mutation rates of 3.29% and VUS rates of 12.19%. Secondary genes had lower pathogenic rates (0.68%) but greater VUS (17.5%). Mutation rates in primary genes peaked at 22% in patients meeting all criteria, whereas those younger than 60 years without family history or syndromic features of CTD had the lowest rate (0.54%).

CONCLUSIONS

Refining genetic testing guidelines to incorporate multiple patient criteria could enhance risk stratification and support informed decision-making in genetic testing for TAD. Limiting testing to genes strongly associated with TAD could lower VUS rates.

Computed Tomography Imaging Measurements as a Surrogate for Clinical Outcomes After Surgical Management of Acute Type A Aortic Dissection: A Systematic Review

BACKGROUND

Postoperative computed tomography imaging surveillance is an essential component of care after acute type A aortic dissection (ATAAD) repair. Prognostic imaging factors after ATAAD repair have not been systematically reviewed.

METHODS AND RESULTS

We performed a systematic review to summarize postoperative computed tomography measurements including aortic diameter, cross-sectional area, volume, growth rate, and false lumen thrombosis in addition mid- to long-term clinical outcomes after ATAAD repair. Searches were conducted in Medline, Embase, and CENTRAL in October 2022. Studies were included if they reported clinical outcomes such as mortality or aortic reintervention after 1 year and included aforementioned computed tomography findings. Studies of chronic aortic dissection and studies of exclusive patient populations such as those with connective tissue diseases were excluded. Risk of bias was assessed with the Newcastle-Ottawa Scale. Searches retrieved 6999 articles. Sixty-eight studies met inclusion criteria (7885 patients). Extended repairs were associated with improved false lumen thrombosis, decreased aortic growth rate, and decreased rates of reintervention but not improved survival. Growth rates of the aorta post-ATAAD repair were highest in the descending thoracic aorta. The most frequent prognostic imaging factors reported were a patent/partially thrombosed false lumen and postoperative aortic diameter >40 to 45 mm.

CONCLUSIONS

Established measurements of positive aortic remodeling, including complete false lumen thrombosis and stabilization of postoperative aortic diameter and growth are the most studied prognostic indicators for improved clinical outcomes after ATAAD repair. Growth rate of the aorta remains significant after ATAAD repair. Future studies should prospectively evaluate and compare prognostic factors for improved surveillance and management.

Correlation of aortic root dimensions and mortality in acute heart failure: A nationwide prospective cohort study

Background

An association between increased aortic root dimensions (ARD) and elevated risk of cardiovascular mortality has been reported in the general population. However, evidence regarding the association between ARD and mortality in patients with acute heart failure (AHF) is limited.

Methods

In a nationwide prospective cohort of the China Patient-Centered Evaluative Assessment of Cardiac Events Prospective Heart Failure Study, ARD was measured during diastole using echocardiography and indexed to body mass index (BMI). Cox proportional hazard models were used to validate the association between BMI-indexed ARD and mortality. Additionally, the relationship between BMI-indexed ARD and mortality was presented using restricted cubic spline in all populations, and both sexes.

Results

A total of 2125 participants with ARD were included in the final analysis, among of 38.4 % were women, with a median age of 67 years. Over a median follow-up period of 54.4 (interquartile range: 30.1 to 59.7) months, 895 deaths occurred, with 750 attributed to cardiovascular causes and 145 to non-cardiovascular causes. Compared to the highest tertile group of BMI-indexed ARD, the lowest tertile group had a lower risk of cardiovascular mortality (hazard ratio [HR], 0.71; 95 % confidence interval [CI], 0.58 to 0.87; P < 0.001) and all-cause mortality (HR, 0.68; 95 % CI, 0.56 to 0.81; P < 0.001). Similarly, the middle tertile group also had a lower risk of cardiovascular mortality (HR, 0.78; 95 % CI, 0.65 to 0.93; P = 0.007) and all-cause mortality (HR, 0.75; 95 % CI, 0.63 to 0.89; P < 0.001). Considering the competing risks, the lowest BMI-indexed ARD groups showed a significant mortality risk of cardiovascular mortality in all populations, and both sexes. Moreover, the relationship between BMI-indexed ARD and mortality was linear in males, while a "J" shaped relationship was observed in females.

Conclusion

Lower BMI-indexed ARD was associated with a decreased risk of all-cause and cardiovascular mortality than those with higher BMI-indexed ARD in AHF. Additionally, a discrepancy was observed between the sexes in the relationship between BMI-indexed ARD and mortality. These findings contribute to the prompt identification of potential mortality risks in patients with AHF.

Early and Late Surgery-Free Rates of Conservative Management Strategy for Thrombosed Type A Acute Aortic Dissection and Acute Intramural Hematoma

Background: We have employed a conservative management approach, including intensive control of both blood pressure and heart rate, in patients with aortic intramural hematoma (AIMH) and retrograde thrombosed type A acute aortic dissection (RT-TAAAD), sharing common clinical and imaging characteristics. Methods: To evaluate the outcomes of our conservative management approach, we retrospectively reviewed the clinical records of 98 patients diagnosed with AIMH or RT-TAAAD from January 2008 to March 2023. A conservative management approach was applied, except for those patients with an aortic diameter ≥ 55 mm, false lumen expansion, or cardiac tamponade, who underwent emergency aortic repair. Results: Besides 2 patients, who declined surgery and subsequently died from aortic rupture, 18 patients underwent urgent aortic surgery, while 78 did not. Multivariable logistic regression analysis identified the extrusion type of ulcer-like projections (ULPs) on admission and a maximum aortic diameter ≥ 45 mm on Day 1 as risk factors for acute aortic surgery. Among the 78 patients who were discharged, 9 (12%) underwent aortic surgery, while 69 (88%) did not, with a median follow-up of 44 months. The overall actuarial aortic surgery-free rates were 78% at 1 year and 72% at 5 years, respectively. A Cox proportional hazards analysis identified ULPs and an aortic diameter ≥ 45 mm at discharge as risk factors for late aortic surgery. Conclusions: The early and late outcomes of our conservative strategy for AIMH and RT-TAAAD demonstrate favorable surgery-free rates. The extrusion type of ULPs on admission and an aortic diameter ≥ 45 mm on Day 1 are predictors of acute aortic surgery, while ULPs and an aortic diameter ≥ 45 mm at discharge are predictors of late surgery.

CD36-mediated ferroptosis destabilizes CD4+ T cell homeostasis in acute Stanford type-A aortic dissection

Acute type A aortic dissection (ATAAD) is a lethal pathological process within the aorta with high mortality and morbidity. T lymphocytes are perturbed and implicated in the clinical outcome of ATAAD, but the exact characteristics of T cell phenotype and its underlying mechanisms in ATAAD remain poorly understood. Here we report that CD4+ T cells from ATAAD patients presented with a hypofunctional phenotype that was correlated with poor outcomes. Whole transcriptome profiles showed that ferroptosis and lipid binding pathways were enriched in CD4+ T cells. Inhibiting ferroptosis or reducing intrinsic reactive oxygen species limited CD4+ T cell dysfunction. Mechanistically, CD36 was elevated in CD4+ T cells, whose blockade effectively alleviated palmitic acid-induced ferroptosis and CD4+ T cell hypofunction. Therefore, targeting the CD36-ferroptosis pathway to restore the functions of CD4+ T cells is a promising therapeutic strategy to improve clinical outcomes in ATAAD patients.

Effect of Sport Activity on Uncomplicated Bicuspid Aortic Valve: Long-Term Longitudinal Echocardiographic Study

BACKGROUND

The bicuspid aortic valve (BAV) is a congenital heart defect that can lead to certain complications (aortic stenosis, regurgitation, dilatation and endocarditis), the diagnosis and clinical monitoring of which are effectively entrusted to transthoracic echocardiography (TTE). The impact of training on the natural history of the disease remains unclear.

METHODS

A retrospective cohort of athletes with uncomplicated BAV aged 18-50 years, who underwent at least 2 TTEs with a minimum follow-up of 5 years, subdivided according to the level of physical activity during follow-up into ''untrained'' and ''trained'', was collected.

RESULTS

47 athletes (87.3% male, median 21.0, (18.0; 33.0) years) were included. Median follow-up was 11.6 (8.4; 16.3) years. No statistically significant difference in the growing rate of aorta, left ventricle, nor a significant worsening of aortic stenosis and regurgitation was found. Moreover, there was no significant correlation between weekly training minutes during follow-up and the echocardiographic parameters related to heart size and function.

CONCLUSIONS

In BAV without major complications, high training volumes do not correspond to a more rapid and significant deterioration in valve function nor to a more rapid increase in aortic or cardiac chamber size.

Cardiovascular Management of Aortopathy in Children: A Scientific Statement From the American Heart Association

Aortopathy encompasses a spectrum of conditions predisposing to dilation, aneurysm, dissection, or rupture of the aorta and other blood vessels. Aortopathy is diagnosed commonly in children, from infancy through adolescence, primarily affecting the thoracic aorta, with variable involvement of the peripheral vasculature. Pathogeneses include connective tissue disorders, smooth muscle contraction disorders, and congenital heart disease, including bicuspid aortic valve, among others. The American Heart Association has published guidelines for diagnosis and management of thoracic aortic disease. However, these guidelines are predominantly focused on adults and cannot be applied adeptly to growing children with emerging features, growth and developmental changes, including puberty, and different risk profiles compared with adults. Management to reduce risk of progressive aortic dilation and dissection or rupture in children is complex and involves genetic testing, cardiovascular imaging, medical therapy, lifestyle modifications, and surgical guidance that differ in many ways from adult management. Pediatric practice varies widely, likely because aortopathy is pathogenically heterogeneous, including genetic and nongenetic conditions, and there is limited published evidence to guide care in children. To optimize care and reduce variation in management, experts in pediatric aortopathy convened to generate this scientific statement regarding the cardiovascular care of children with aortopathy. Available evidence and expert consensus were combined to create this scientific statement. The most common causes of pediatric aortopathy are reviewed. This document provides a general framework for cardiovascular management of aortopathy in children, while allowing for modification based on the personal and familial characteristics of each child and family.

Next-Generation Frozen Elephant Trunk Technique in the Era of Precision Medicine

The frozen elephant trunk (FET) technique can be applied to extensive aortic pathology, including lesions in the aortic arch and proximal descending thoracic aorta. FET is useful for tear-oriented surgery in dissections, managing malperfusion syndrome, and promoting positive aortic remodeling. Despite these benefits, complications such as distal stent-induced new entry and spinal cord ischemia can pose serious problems with the FET technique. To prevent these complications, careful sizing and planning of the FET are crucial. Additionally, since the FET technique involves total arch replacement, meticulous surgical skills are essential, particularly for young surgeons. In this article, we propose several techniques to simplify surgical procedures, which may lead to better outcomes for patients with extensive aortic pathology. In the era of precision medicine, the next-generation FET device could facilitate the treatment of complex aortic diseases through a patient-tailored approach.

Evaluating current acute aortic syndrome pathways: Collaborative Acute Aortic Syndrome Project (CAASP)

BACKGROUND

Diagnosis of acute aortic syndrome is challenging and associated with high perihospital mortality rates. The study aim was to evaluate current pathways and understand the chronology of acute aortic syndrome patient care.

METHOD

Consecutive patients with acute aortic syndrome imaging diagnosis between 1 January 2018 and 1 June 2021 were identified using a predetermined search strategy and followed up for 6 months through retrospective case note review. The UK National Interventional Radiology Trainee Research and Vascular and Endovascular Research Network co-ordinated the study.

RESULTS

From 15 UK sites, 620 patients were enrolled. The median age was 67 (range 25-98) years, 62.0% were male and 92.9% Caucasian. Type-A dissection (41.8%) was most common, followed by type-B (34.5%); 41.2% had complicated acute aortic syndrome. Mode of presentation included emergency ambulance (80.2%), self-presentation (16.2%), and primary care referral (3.6%). Time (median (i.q.r.)) to hospital presentation was 3.1 (1.8-8.6) h and decreased by sudden onset chest pain but increased with migratory pain or hypertension. Time from hospital presentation to imaging diagnosis was 3.2 (1.3-6.5) h and increased by family history of aortic disease and decreased by concurrent ischaemic limb. Time from diagnosis to treatment was 2 (1.0-4.3) h with interhospital transfer causing delay. Management included conservative (60.2%), open surgery (32.2%), endovascular (4.8%), hybrid (1.4%) and palliative (1.4%). Factors associated with a higher mortality rate at 30 days and 6 months were acute aortic syndrome type, complicated disease, no critical care admission and age more than 70 years (P < 0.05).

CONCLUSIONS

This study presents a longitudinal data set linking time-based delays to diagnosis and treatment with clinical outcomes. It can be used to prioritize research strategies to streamline patient care.

Perioperative and Long-Term Outcomes of Acute Stanford Type A Aortic Dissection Repair in Octogenarians

BACKGROUND

The aims of this study were to assess the perioperative morbidity, mortality and long-term survival of octogenarians undergoing acute type A aortic dissection repair (ATAAD), and to compare open and closed distal anastomosis techniques.

METHODS

This was a single-centre retrospective study (2007-2021). Open versus closed distal anastomosis were compared. Uni- and multivariable logistic regression analyses were performed to identify independent predictors of in-hospital mortality. Kaplan-Meier and Cox proportional hazards methods were used to compare long-term survival.

RESULTS

Fifty octogenarian patients were included (median age-82 years; closed distal-22; open distal-28). Median cardiopulmonary bypass time was 187 min (open distal vs. closed distal group; 219 min vs. 115.5 min, p < 0.01, respectively). Median cross-clamp time was 93 min (IQR; 76-130 min). Median circulatory arrest time was 26 min (IQR; 20-39 min) in the open-distal group. In-hospital mortality was 18% (open distal; 14.2% vs. closed distal; 22.7%, p = 0.44). Stroke was 26% (open distal; 28.6% vs. closed distal; 22.7%, p = 0.64). Median survival was 7.2 years (IQR; 4.5-11.6 years). Survival was comparable between open and closed distal groups (median 10.6 vs. 7.2 years, p = 0.35, respectively). Critical preoperative status (HR; 3.2, p = 0.03) and composite endpoint (renal replacement therapy, new neurological event, length of stay > 30 days or return to theatre; HR; 4.1, p = 0.02) predicted adverse survival. Open distal anastomosis did no impact survival.

CONCLUSIONS

ATAAD repair in selected octogenarians has acceptable short- and long-term survival. There is no significant difference between open versus closed distal anastomosis strategies.

Coronary angiography following transcatheter aortic valve replacement: Insights from the SWEDEHEART registry

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is the most common treatment in patients with symptomatic severe aortic stenosis (AS). As concomitant coronary artery disease is common in AS patients, access to the coronary arteries following TAVR is of increasing importance.

OBJECTIVES

This study evaluated the incidence and risk factors for unplanned coronary angiography following TAVR and, using fluoroscopic time as a surrogate, analyzed the complexity of coronary artery cannulation.

METHODS

All patients who underwent TAVR in Sweden between 2008 and 2022 were identified using the SWEDEHEART registry. The cumulative incidence of coronary angiography after TAVR was analyzed with mortality as a competing risk. Angiography and PCI complexity were analyzed using fluoroscopic time and compared across different transcatheter heart valve designs.

RESULTS

Out of 9806 patients, 566 subsequently required coronary angiography. The incidence was highest for three-vessel and/or left main disease. Younger age, the extent of prior coronary artery disease, and peripheral vascular disease were associated with an increased risk of coronary angiography. Fluoroscopy time was increased in TAVR patients compared to the control group with the longest fluoroscopy times observed in cases involving supra-annular and self-expanding valves.

CONCLUSIONS

The incidence of coronary angiography following TAVR is still low. Younger patients and patients with concomitant coronary artery disease have a higher risk. Procedural time is longer in patients with a previous THV replacement. As TAVR is emerging as the first-line treatment in patients with longer life expectancy, facilitating coronary access is an important factor when considering which THV device to implant.

Predictors of In-Hospital Mortality in Type A Acute Aortic Syndrome: Data From the RENADA-RO Registry

BACKGROUND

This study aimed to analyse the baseline characteristics of patients admitted with acute type A aortic syndrome (ATAAS) and to identify the potential predictors of in-hospital mortality in surgically managed patients.

METHODS

Data regarding demographics, clinical presentation, laboratory work-up, and management of 501 patients with ATAAS enrolled in the National Registry of Aortic Dissections-Romania registry from January 2011 to December 2022 were evaluated. The primary endpoint was in-hospital all-cause mortality. Multivariate logistic regression was conducted to identify independent predictors of mortality in patients with acute Type A aortic dissection (ATAAD) who underwent surgery.

RESULTS

The mean age was 60±11 years and 65% were male. Computed tomography was the first-line diagnostic tool (79%), followed by transoesophageal echocardiography (21%). Cardiac surgery was performed in 88% of the patients. The overall mortality in the entire cohort was 37.9%, while surgically managed ATAAD patients had an in-hospital mortality rate of 29%. In multivariate logistic regression, creatinine value (OR 6.76), ST depression on ECG (OR 6.3), preoperative malperfusion (OR 5.77), cardiogenic shock (OR 5.77), abdominal pain (OR 4.27), age ≥70 years (OR 3.76), and syncope (OR 3.43) were independently associated with in-hospital mortality in surgically managed ATAAD patients.

CONCLUSIONS

Risk stratification based on the variables collected at admission may help to identify ATAAS patients with high risk of death following cardiac surgery.

Blood Pressure Management for Hypotensive Patients in Intensive Care and Perioperative Cardiovascular Settings

Blood pressure is a critical physiological parameter, particularly in the context of cardiac intensive care and perioperative settings. As a primary indicator of organ perfusion, the maintenance of adequate blood pressure is imperative for the assurance of sufficient tissue oxygen delivery. Among critically ill and major surgery patients, the continuous monitoring of blood pressure is performed as a standard practice for patients. Nonetheless, uncertainties remain regarding blood pressure goals, and there is no consensus regarding blood pressure targets. This review describes the determinants of blood pressure, examine the influence of blood pressure on organ perfusion, and synthesize the current clinical evidence from various intensive care and perioperative settings to provide a concise guidance for daily clinical practice.

The cardiovascular pathologist in the aortic team

Aortic diseases require a multidisciplinary management for diagnosis, treatment and follow-up with better outcomes in referral centers using a team-based approach. The setting up of a multi-disciplinary aortic team for the discussion of complex cases has been already proposed; it is also supported by the ACC/AHA. Surgeons and radiologists, more or less other physicians such as cardiologists, geneticists, rheumatologists/internal medicine specialists and pathologists are involved into such a team. The role of the cardiovascular pathologist is to examine the aortic specimens, to diagnose and classify the aortic lesions. Herein, the role of the pathologist in the aortic team is discussed and the pathobiology of aortic diseases is reviewed for reference by pathologists. The aortic specimens are mainly obtained from emergency or elective surgical procedures on the thoracic aorta, less frequently from organ/tissue (including cardiac or heart valve) donors, post-mortem procedures or abdominal aortic surgery. In the last decade, together with the progress of medical sciences, the histological definitions and classifications of the aortic pathology are undergoing thorough revisions that are addressed to an etiopathogenetic approach because of possible clinico-pathological correlations, therapeutic and prognostic impact. Pathologists may also have an important role in research and teaching. Therefore, histological analyses of the aortic specimens require adequate sample processing and pathologist expertise because histology contributes to definite diagnosis, correct management of patients and even (in genetic diseases) families, but also to research in the challenging field of aortopathies.

Natural history and long-term outcomes of medically managed Type B intramural hematoma

OBJECTIVE

Type B intramural hematoma (IMH) is often managed medically, yet may progress to dissection, aneurysmal dilation, or rupture. The aim of this study was to report the natural history of medically managed Type B IMH, and factors associated with progression.

METHODS

We reviewed patients with medically managed Type B IMH between January 1995 to December 2022 at a single center. Any patients with immediate surgical or endovascular intervention were excluded. Demographic profiles, comorbidities, imaging, and follow-up details were reviewed. Patients were divided into two groups: Group 1 had isolated IMH, and Group 2 had IMH along with aneurysm or dissection at the time of presentation. On follow-up, progression was defined as degeneration to aneurysm/dissection or increase in the thickness of IMH in Group 1. In Group 2, progression was an increase in the size of aneurysm or development of new dissection.

RESULTS

Of 104 patients with Type B IMH during the study period, 92 were medically managed. The median age was 77 years, and 45 (48.9%) were females. Comorbidities included hypertension (83.7%), hypercholesterolemia (44.6%), and active smoking (47.8%). Mean Society for Vascular Surger comorbidity score was 6.3. Mean IMH thickness and aortic diameter at presentation were 8.9 mm and 38.3 mm, respectively. Median follow-up was 55 months. Overall survival at 1 year and 5 years was 85.8% and 61.9%, respectively. During follow-up, 19 patients (20.7%) required intervention, more common in Group 2 (Group 1, 8/66; 12.3% vs Group 2, 11/26; 42.3%; P = .001). This resulted in higher freedom from intervention in Group 1 at 1 year (93.5% vs 62.7%) and 5 years (87.5% vs 51.1%; P < .001). Indication for intervention was dissection (n = 4), aneurysm (n = 12), and progression of IMH (n = 3). In Group 1, progression was seen in 25 (37.9%), three (4.5%) remained stable, 29 (43.9%) had complete resolution of IMH, and nine patients were lost to follow-up. In Group 2, 11 patients (42.3%) had progression, seven (26.9%) remained stable, and eight were lost to follow-up. IMH thickness at presentation >7.2 mm is associated with both increased odds of progression (odds ratio, 3.3; 95% confidence interval, 1.2-11.1; P = .03) and intervention (odds ratio, 5.5; 95% confidence interval, 1.3-36.9; P = .03) during the follow-up.

CONCLUSIONS

Although many patients with Type B IMH managed medically stabilize or regress, progression or need for intervention can occur in up to 40% of cases. This is associated with the presence of aneurysm, dissection, and IMH thickness. Long-term follow-up is mandatory as late interventions occur, particularly for higher risk patients.

Night-time surgery for type a aortic dissection: Immediate or delaying?

OBJECTIVES

This study aims to investigate whether surgery performed during night compared with daytime were associated with an increased risk of operative mortality of type A aortic dissection (TAAD) patients.

METHODS

A total of 2015 TAAD patients who underwent surgical repair were collected from two cardiovascular centers from Jan 2015 to Jan 2021. According to the start time of surgery, patients were divided into daytime group (06:01 a.m. to 06:00 p.m.) and night-time group (06:01 p.m. to 06:00 a.m.), and retrospective analyses were performed between them.

RESULTS

The operative mortality of night-time group (12.2%, 43/352) was dramatically higher than daytime group (6.9%, 115/1663; p = 0.001). There was significant difference between night-time and daytime groups in terms of 30-days mortality (5.8% vs 10.8%; p = 0.001) and in-hospital mortality (3.5% vs 6.0%; p = 0.03). The night-time group had a longer duration of intensive care unit stay (4 vs two; days; p < 0.001) and ventilation support (34 vs 19; hours; p < 0.001), compared with daytime group. The risk factors for operative mortality were night-time surgery (odds ratio [OR], 1.545; p = 0.027), age (odds ratio, 1.152; p < 0.001), total arch replacement (OR, 2.265; p < 0.001) and previous aortic surgery (OR, 2.376; p = 0.003).

CONCLUSION

Night-time surgical repair may be associated with higher operative mortality of patients with TAAD. Nevertheless, it is reasonable to offer emergency surgery at night-time for such patients who were more likely to present disastrous complications with delayed surgical intervention, as outcomes indicate acceptable operative mortality.

The Year in Aortic Surgery: Selected Highlights From 2023

This article reviews the recent and relevant literature to the field of aortic surgery. Specific areas highlighted include outcomes of Stanford type A dissection, management of acute aortic syndromes, management of aortic aneurysms, and traumatic aortic injury. Although the focus was on articles from 2023, literature from prior years also was included, given that this article is the first of a series. Notably, the pertinent sections from the 2022 American College of Cardiology/American Heart Association Guidelines for the Diagnosis and Management Aortic Disease are discussed.

Abnormal Cardiac Magnetic Resonance-Derived Ascending Aortic Area Strain Demonstrates Altered Ventriculo-Vascular Function in Marfan Syndrome

PURPOSE

There remains a need for improved imaging markers for risk stratification and treatment guidance in Marfan syndrome (MFS). After aortic root replacement (ARR), vascular remodeling and progressive aneurysm formation can occur due to alterations in up- and downstream wall biomechanics and hemodynamics. We aim to compare the ventriculo-vascular properties of patients with MFS with controls, and investigate the correlation between ascending aortic area strain and descending aortic area strain (DAAS) with other clinical variables.

PATIENTS AND METHODS

Nineteen patients with MFS (47% males), including 6 with ARR were studied. In 26 studies, aortic area strain was measured using cross-sectional cardiac magnetic resonance images at the ascending and proximal descending aortic levels. Left atrial, left ventricular longitudinal, and left ventricle circumferential strain (left atrial longitudinal strain, left ventricular longitudinal strain, and left ventricular circumferential strain, respectively) were measured using cardiac magnetic resonance-feature tracking.

RESULTS

Compared with healthy controls, patients with MFS had significantly impaired left ventricular longitudinal strain and left ventricular circumferential strain (-15.8 ± 4.7 vs -19.7 ± 4.8, P = 0.005, and -17.7 ± 4.0 vs -27.0 ± 4.1, P < 0.001). Left atrial longitudinal strain was comparable between patients with MFS and controls. AAAS was significantly reduced (19.0 [11.9, 23.7] vs 46.1 ± 11.3, P < 0.001), whereas DAAS was not significantly decreased. AAAS and DAAS were negatively correlated with age, whereas no significant associations were identified with left ventricle function indices. No significant differences were observed between the ventriculo-vascular properties of patients with MFS who underwent ARR and those who did not.

CONCLUSION

Patients with MFS demonstrated impaired ventricular and vascular function compared with healthy controls. Further investigations are warranted to determine clinical utility of aortic stiffness indices for predicting primary and repeat aortic events.

Aortic aneurysm: pathophysiology and therapeutic options

Aortic aneurysm (AA) is an aortic disease with a high mortality rate, and other than surgery no effective preventive or therapeutic treatment have been developed. The renin-angiotensin system (RAS) is an important endocrine system that regulates vascular health. The ACE2/Ang-(1-7)/MasR axis can antagonize the adverse effects of the activation of the ACE/Ang II/AT1R axis on vascular dysfunction, atherosclerosis, and the development of aneurysms, thus providing an important therapeutic target for the prevention and treatment of AA. However, products targeting the Ang-(1-7)/MasR pathway still lack clinical validation. This review will outline the epidemiology of AA, including thoracic, abdominal, and thoracoabdominal AA, as well as current diagnostic and treatment strategies. Due to the highest incidence and most extensive research on abdominal AA (AAA), we will focus on AAA to explain the role of the RAS in its development, the protective function of Ang-(1-7)/MasR, and the mechanisms involved. We will also describe the roles of agonists and antagonists, suggest improvements in engineering and drug delivery, and provide evidence for Ang-(1-7)/MasR's clinical potential, discussing risks and solutions for clinical use. This study will enhance our understanding of AA and offer new possibilities and promising targets for therapeutic intervention.

Sex Comparative Analysis of Branched and Fenestrated Endovascular Aortic Arch Repair Outcomes

OBJECTIVE

Female sex is a risk factor for adverse events after endovascular aortic repair. Sex comparative early and midterm outcomes of fenestrated and branched endovascular aortic arch repair (F/B-Arch) are presented.

METHODS

A single centre retrospective sex comparative analysis of consecutive patients managed with F/B-Arch was conducted according to STROBE. Primary outcomes were sex comparative technical success, death, and cerebrovascular morbidity at 30 days. Kaplan-Meier estimates were used for follow up outcomes.

RESULTS

Among 209 patients, 38.3% were women. Coronary artery disease (p < .001) and previous myocardial infarction (p = .01) were more common in women. Non-native proximal aortic landing was higher in women (women: 51.3%; men: 31.8%, p = .005) and the aortic dissection rate was lower (28.8% vs. 48.1%, p = .005). Proximal landing to Ishimaru zones showed no difference (zone 0: p = .18; zone 1: p = .47; zone 2: p = .39). Graft configurations were equally distributed. In total, 416 supra-aortic trunks were bridged. The median number of revascularisations per patient was two (interquartile range 1, 3), with no difference between sexes (p = .54). Technical success (women: 97.5%; men: 96.9%, p = .80), 30 day mortality rate (women: 10%; men: 9.3%, p = .86), and cerebrovascular morbidity (women: 11.3%; men: 17.1%, p = .25) were similar. Women presented more access related complications (women: 32.5%; men: 16.3%, p = .006), without affecting access related re-interventions (p = .55). Survival (women: 81.1%, 95% confidence interval [CI] 76.3 - 85.9%; men: 79.8%, 95% CI 76.0 - 83.6%) and freedom from re-intervention (women: 56.6%, 95% CI 50.4 - 62.8%; men: 55.3%, 95% CI 50.1 - 60.5%) at 12 months were similar (log rank, p = .40 and p = .41, respectively).

CONCLUSION

Both sexes presented similar outcomes after F/B-Arch. Appropriate patient selection may decrease the effect of sex in F/B-Arch outcomes.

Admission Left-Arm Systolic Blood Pressure and In-Hospital Mortality After Acute Type A Aortic Dissection Repair

AIM

Admission systolic blood pressure is a significant predictor of in-hospital mortality in patients with acute type A aortic dissection (ATAAD). While previous studies have focussed on recording the highest blood pressure value from both arms, this study aimed to evaluate the associations between blood pressure in bilateral arms and in-hospital mortality.

METHODS

Data were analysed from 262 patients with ATAAD treated at a single centre. The relationship between bilateral arm blood pressure upon admission and in-hospital mortality was assessed in a logistic regression model. To comprehensively evaluate potential non-linear relationships, the association between admission bilateral systolic blood pressure (SBP) and the risk of in-hospital mortality was analysed using restricted cubic splines on a continuous scale.

RESULTS

Mean age was 53.6±12.5 years and 194 (74.0%) were male. Baseline and operative data showed that ages, body mass index, smoking, left-arm SBP, left-arm diastolic blood pressure (DBP), right-arm SBP, right-arm DBP, syncope, cerebral/cardiac ischaemia, retrograde brain perfusion, Bentall procedure, coronary artery bypass grafting, and aortic valve replacement significantly differed among the left-arm SBP tertiles. In-hospital mortality was 17.6% (46 of 262). Restricted cubic splines demonstrated that the relationship between presenting left-arm SBP and in-hospital mortality followed a U-shaped curve, whereas non-linearity was not detected in the right arm.

CONCLUSION

This study found a U-shaped association between admission left-arm SBP and in-hospital mortality in ATAAD surgery patients, whereas a non-linearity relationship was not detected for right-arm SBP. Low left-arm SBP independently correlated with increased in-hospital mortality, underscoring the significance of bilateral blood pressure differences in ATAAD prognosis.

A morphological indicator for aortic dissection: fitting circle of the thoracic aorta

BACKGROUND

This study aims to identify a morphological indicator of aortic dissection (AD) based on the geometrical characteristics of the thoracic aorta.

METHODS

We evaluated computed tomographic angiograms of 63 samples with AD (22 with type A AD, 41 with type B AD) and 71 healthy samples. Via centerline extraction and spatial transformation, the spatial entanglement of the aorta was minimized, and the expanded 2D aortic morphology was obtained. The 2D morphology of the thoracic aorta was fit to a circle. The applicability of the fitting circle method for identifying aortic dissection was verified by multivariable logistic regression analysis.

RESULTS

Via the 3D coordinate transformation algorithm, the optimal aortic view was obtained. On this view, the geometrical characteristics of the thoracic aortas of the healthy controls were similar to a portion of a circle (sum of residuals: 3502.45 ± 2566.71, variance: 86.23 ± 56.60), while that of AD samples had poorer similarity to the circle (sum of residuals: 5404.78 ± 3891.69, variance: 129.90 ± 90.09). This difference was significant (p < 0.001). A logistic regression model showed that increased deformation of the thoracic aorta was a significant indicator of aortic dissection (odds ratio: 1.35, p = 0.034).

CONCLUSIONS

The morphology of the healthy thoracic aorta could be fit to a circle, while that of the dissected aorta had poorer similarity to the circle. The statistics of the circle are an effective indicator of aortic deformation in AD.

TRIAL REGISTRATION

This study is registered in the Chinese Clinical Trial Registry (ChiCTR2000029219).

Gender-Dependent Association of Pulmonary Hypertension with Adverse Outcomes in Patients Undergoing Transcatheter Aortic Valve Replacement

Background

The relationship between pulmonary hypertension (PH) and outcomes after transcatheter aortic valve replacement (TAVR) has been shown to be unfavorable. The impact of gender on TAVR outcomes remains controversial. There have been no studies evaluating the simultaneous effects of both factors on TAVR outcomes.

Methods

We retrospectively analyzed a prospective cohort of patients who underwent TAVR between January 2016 and December 2022. The patients were stratified by gender and the presence of PH. The primary outcome of the study was all-cause mortality. Secondary outcome was a composite of all-cause mortality and heart failure hospitalization.

Results

We identified a total of 133 female patients without PH, 179 males without PH, 87 females with PH, and 122 males with PH. The median follow-up period was 18 months. Female patients without PH demonstrated a lower cumulative mortality rate compared to those with male gender and/or PH. Adjusted multivariate Cox proportional hazard analyses revealed that male gender and PH status, either individually or in combination, were independently associated with long-term mortality when compared to female patients without PH. Specifically, females with PH (HR 6.80, 95% confidence interval (CI): 1.49-31.12, P=0.013), males without PH (HR 6.45, 95% CI: 1.47-28.22, P=0.013), and males with PH (HR 7.2, 95% CI: 1.63-31.81, P=0.009) demonstrated significantly higher risk for mortality.

Conclusion

Patients who were male or had PH status had a higher risk of mortality. However, there was no synergistic effect between being male and having PH on the prognosis after TAVR.

Comparison of Biomechanical and Microstructural Properties of Aortic Graft Materials in Aortic Repair Surgeries

Mechanical mismatch between native aortas and aortic grafts can induce graft failure. This study aims to compare the mechanical and microstructural properties of different graft materials used in aortic repair surgeries with those of normal and dissected human ascending aortas. Five types of materials including normal aorta (n = 10), dissected aorta (n = 6), human pericardium (n = 8), bovine pericardium (n = 8) and Dacron graft (n = 5) were collected to perform uniaxial tensile testing to determine their material stiffness, and ultimate strength/stretch. The elastin and collagen contents in four tissue groups except for Dacron were quantified by histological examinations, while the material ultrastructure of five material groups was visualized by scanning electron microscope. Statistical results showed that three graft materials including Dacron, human pericardium and bovine pericardium had significantly higher ultimate strength and stiffness than both normal and dissected aortas. Human and bovine pericardia had significantly lower ultimate stretch than native aortas. Histological examinations revealed that normal and diseased aortic tissues had a significantly higher content of elastic fiber than two pericardial tissues, but less collagen fiber content. All four tissue groups exhibited lamellar fiber ultrastructure, with aortic tissues possessing thinner lamella. Dacron was composed of densely coalesced polyethylene terephthalate fibers in thick bundles. Aortic graft materials with denser fiber ultrastructure and/or higher content of collagen fiber than native aortic tissues, exhibited higher ultimate strength and stiffness. This information provides a basis to understand the mechanical failure of aortic grafts, and inspire the design of biomimetic aortic grafts.

Diagnostic Performance of a Deep Learning-Powered Application for Aortic Dissection Triage Prioritization and Classification

This multicenter retrospective study evaluated the diagnostic performance of a deep learning (DL)-based application for detecting, classifying, and highlighting suspected aortic dissections (ADs) on chest and thoraco-abdominal CT angiography (CTA) scans. CTA scans from over 200 U.S. and European cities acquired on 52 scanner models from six manufacturers were retrospectively collected and processed by CINA-CHEST (AD) (Avicenna.AI, La Ciotat, France) device. The diagnostic performance of the device was compared with the ground truth established by the majority agreement of three U.S. board-certified radiologists. Furthermore, the DL algorithm's time to notification was evaluated to demonstrate clinical effectiveness. The study included 1303 CTAs (mean age 58.8 ± 16.4 years old, 46.7% male, 10.5% positive). The device demonstrated a sensitivity of 94.2% [95% CI: 88.8-97.5%] and a specificity of 97.3% [95% CI: 96.2-98.1%]. The application classified positive cases by the AD type with an accuracy of 99.5% [95% CI: 98.9-99.8%] for type A and 97.5 [95% CI: 96.4-98.3%] for type B. The application did not miss any type A cases. The device flagged 32 cases incorrectly, primarily due to acquisition artefacts and aortic pathologies mimicking AD. The mean time to process and notify of potential AD cases was 27.9 ± 8.7 s. This deep learning-based application demonstrated a strong performance in detecting and classifying aortic dissection cases, potentially enabling faster triage of these urgent cases in clinical settings.

Aortic aneurysms in a general population cohort: prevalence and risk factors in men and women

AIMS

The prevalence and difference in risk factors for having thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) in men compared with women in the general population is not well described. This study aimed to test the hypotheses that (i) cardiovascular risk factors for TAA and AAA differ and (ii) the prevalence of TAA and AAA is sex specific.

METHODS AND RESULTS

Aortic examination using computed tomography angiography was performed in 11 294 individuals (56% women), with a mean age of 62 (range 40-95) years participating in the Copenhagen General Population Study. TAAs were defined as an ascending aortic diameter ≥45 mm and a descending aortic diameter ≥35 mm, while AAAs were defined as an abdominal aortic diameter ≥30 mm. Demographic data were obtained from questionnaires. Overall prevalence of aortic aneurysms (AAs) in the study population included: total population 2.1%, men 4.0% and women 0.7% (P-value men vs. women P < 0.001). AAs were independently associated with male sex, increasing age, and body surface area (BSA). While TAAs were associated with hypertension, odds ratio (OR) = 2.0 [95% confidence interval (CI): 1.5-2.8], AAAs were associated with hypercholesterolaemia and smoking, OR = 2.4 (95% CI: 1.6-3.6) and 3.2 (95% CI: 1.9-5.4).

CONCLUSION

Subclinical AAs are four times more prevalent in men than in women. In both sexes, increasing age and BSA are risk factors for AAs of any anatomical location. Whereas arterial hypertension is a risk factor for TAAs, hypercholesterolaemia and smoking are risk factors for AAAs.

Comparative analysis of long-term outcomes in thoracoabdominal aortic aneurysm repair between Marfan syndrome patients and non-Marfan syndrome patients

BACKGROUND

A consensus on the management of thoracoabdominal aortic aneurysm (TAAA) in patients with Marfan syndrome (MFS) has not yet been established. This study aimed to compare the long-term outcomes after open TAAA repair in patients with and without MFS.

METHODS

This retrospective study examined 230 consecutive patients who underwent TAAA repair between 2012 and 2022, including of 69 MFS patients and 161 non-MFS patients. The primary endpoint was long-term mortality. The secondary endpoint was a composite of early adverse events, including early mortality, permanent stroke, permanent paraplegia, permanent renal failure, and reoperation. Univariable and multivariable logistic regression analyses were used to assess the impact of MFS on early composite adverse events, and univariable and multivariable Cox proportional hazards models were constructed to evaluate the association between MFS and overall mortality.

RESULTS

Compared with non-MFS patients, MFS patients were younger (mean, 31.9 ± 8.5 years vs 44.8 ± 12.3 years; P < .001), had less comorbid coronary artery disease (0 vs 8.1%; P = .034), more frequently underwent Crawford extent III repair (56.5% vs 34.8%; P = .002) and applied normothermic iliac perfusion (91.3% vs 81.4%; P = .057). There was no significant difference in the rate of early composite adverse events between the MFS and non-MFS groups (23.2% vs 14.3%; P = .099), which was verified by multivariable logistic regression analyses with multiple models. Overall mortality was significantly lower in the MFS group compared to the non-MFS group (P = .026, log-rank test), with 1-, 5-, and 10-year cumulative mortality of 4.4% versus 8.7%, 8.1% versus 17.2%, and 20.9% versus 36.4%, respectively. Multivariable Cox regression analyses across different models further confirmed MFS as a significant protective factor for overall mortality (model 1: hazard ratio [HR], 0.31; 95% confidence interval [CI] 0.13-0.73; P = .007; model 2: HR, 0.32, 95% CI, 0.13-0.75; P = .009; model 3: HR, 0.38; 95% CI, 0.15-0.95; P = .039).

CONCLUSIONS

Despite varying risk profiles, MFS patients undergoing open TAAA repair can achieve comparable or even superior outcomes to non-MFS patients with tailored surgical strategies, meticulous perioperative care, and close follow-up surveillance, especially in the long term.

Impact of early diagnosis on surgical outcomes in patients with Loeys-Dietz syndrome

Background

This study aimed to investigate the influence of early diagnosis (ED) on surgical outcomes in patients definitively diagnosed with Loeys-Dietz syndrome (LDS).

Methods

A retrospective review was conducted on 38 patients with LDS who underwent aortic surgery at our institution between January 1995 and June 2022. The primary endpoint was freedom from aortic reoperation.

Results

Among the patients, the median age at the initial surgery was 33 (range: 39-44) years, and 23 (60.5%) patients were male. Twenty-one (55.3%; aortic dissection or rupture (n = 2) and aneurysm (n = 19)) patients were diagnosed with LDS before the initial surgery (ED group). Meanwhile, the remaining 17 (44.7%; aortic dissection or rupture (n = 13) and aneurysm (n = 4)) patients were after surgery [delayed diagnosis (DD) group]. The ED group had significantly lower rates of emergency surgery and concomitant arch procedure (P < .001, respectively) but a higher rate of valve-sparing root surgery (P = .018) compared to the DD group. No in-hospital mortality was observed in either group. Nevertheless, the ED group had a shorter postoperative hospital stay (median difference: 3 days, P = .032) and a lower rate of aortic reoperation (P = .013).

Conclusion

Early detection of LDS may help in preventing acute aortic syndrome, reducing the risk of aortic reoperation, and potentially shortening hospital stay. Careful medical management before surgery could contribute to better clinical outcomes and an improved quality of life for patients with LDS.

Predictors for thoracic aortic growth in patients with type B aortic dissection after thoracic endovascular aortic repair

OBJECTIVE

To identify independent predictors of thoracic aortic growth in patients with type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR).

METHODS

A retrospective analysis of the patients undergoing TEVAR for TBAD or intramural hematoma (IMH) from April 2014 to April 2023 was performed. The baseline morphological data of TBAD was established through computed tomography angiography (CTA) before discharge. Patients were divided into two groups based on aortic growth: growth and no growth. Aortic growth defined as an increase ≥5 mm in thoracic maximal aortic diameter during any serial follow-up CTA measurement. Logistic regression following propensity score matching (PSM) was used to identify independent predictors for aortic growth. Receiver operating characteristic curve and cutoff value of independent predictors were calculated. Linear regression was used to establish a correlation between anatomical variables and follow-up aortic diameter.

RESULTS

A total of 145 patients with TBAD (n = 122) or IMH (n = 23) undergoing TEVAR were included, with a male of 83.4% and a mean age of 56 ± 14.1 years. Patients in growth group and no growth group was 26 (17.9%) and 119 (80.1%), respectively. After using PSM method, matched regression analysis showed residual maximal tear diameter (OR = 0.889, 95% CI 0.830-0.952, p = 0.001) and follow-up aortic diameter (OR = 0.977, 95% CI 0.965-0.989, p < 0.001) were independent predictors for aortic growth. The cutoff value was 8.55 mm for residual tear diameter and 40.65 mm for follow-up maximal aortic diameter. The residual maximal tear diameter showed a linear correlation with follow-up aortic diameter (DW = 1.74, R2 = 6.2%, p = 0.033).

CONCLUSIONS

This study suggested that residual maximal tear diameter >8.55 mm and follow-up aortic diameter >40.65 mm could predict aortic growth in patients with TBAD undergoing TEVAR.

A 25-Year-Old With an Incidentally Detected Ascending Thoracic Aortic Aneurysm and Bicuspid Aortic Valve

A woman had shortness of breath and a first-degree relative with a history of ascending aorta dissection. Imaging showed an isolated dilatation in the mid ascending aorta and a bicuspid aortic valve but no pulmonary infiltrates, effusion, or embolism and no aortic stenosis or regurgitation. What would you do next?

Comprehensive sex-specific and age-dependent analysis of four-dimensional flow cardiovascular magnetic resonance assessed aortic blood flow-related parameters in normal subjects using single-vendor magnetic resonance systems and single-vendor software

BACKGROUND

Aortic blood flow characterization by four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) is increasingly performed in aneurysm research. A limited number of studies have established normal values that can aid the recognition of abnormal flow at an early stage. This study aims to establish additional sex-specific and age-dependent reference values for flow-related parameters in a large cohort of healthy adults.

METHODS

Two hundred and twelve volunteers were included, and 191 volunteers completed the full study protocol. All underwent 4D flow CMR of the entire aorta. Quantitative values for velocity, vorticity, helicity, as well as total, circumferential, and axial wall shear stress (WSS) were determined for the aortic root (AoR), ascending aorta (AAo), aortic arch, descending aorta (DAo), suprarenal aorta, and infrarenal aorta. Vorticity and helicity were indexed for segment volume (mL).

RESULTS

The normal values were estimated per sex and age group, where significant differences between males (M) and females (F) were found only for specific age groups. More specifically, the following variables were significantly different after applying the false discovery rate correction for multiple testing: 1) velocity in the AAo and DAo in the 60-70 years age group (mean ± SD: (M) 47.0 ± 8.2 cm s-1 vs (F) 38.4 ± 6.9 cm s-1, p = 0.001 and, (M) 55.9 ± 9.9 cm s-1 vs (F) 46.5 ± 5.5 cm s-1, p = 0.002), 2) normalized vorticity in AoR in the 50-59 years age group ((M) 27,539 ± 5042 s-1 mL-1 vs (F) 30,849 ± 7285 s-1 mL-1, p = 0.002), 3) axial WSS in the Aao in the 18-29 age group ((M) 1098 ± 203 mPa vs (F) 921 ± 121 mPa, p = 0.002). Good to strong negative correlations with age were seen for almost all variables, in different segments, and for both sexes.

CONCLUSION

This study describes reference values for aortic flow-related parameters acquired by 4D flow MRI. We observed limited differences between males and females. A negative relationship with age was seen for almost all flow-related parameters and segments.

A novel hybrid prosthesis for open repair of acute DeBakey type I dissection with malperfusion: Early results from the PERSEVERE trial

BACKGROUND

Outcomes after hemiarch repair for acute DeBakey type I aortic dissection (ADTI) remain unfavorable, with high rates of major adverse events and negative aortic remodeling. The PERSEVERE study evaluates the safety and effectiveness of the AMDS Hybrid prosthesis, a novel bare metal stent, in patients presenting with preoperative malperfusion.

METHODS

PERSEVERE is a prospective single-arm investigational study conducted at 26 sites in the United States. Ninety-three patients underwent ADTI aortic dissection repair with AMDS implantation. The 30-day primary endpoints are a composite rate of 4 major adverse events and the rate of distal anastomotic new entry tears. The secondary endpoints include aortic remodeling.

RESULTS

Clinical malperfusion was documented in 76 patients (82%); only radiographic malperfusion, in 17 (18%). The median follow-up in the 93 patients was 5.6 months. Within 30 days, 9 patients died (9.7%), 10 patients (10.8%) experienced new disabling stroke, and 18 patients (19.4%) had new-onset renal failure requiring ≥1 dialysis treatment. There were no cases of myocardial infarction. The composite rate of major adverse events (27%) was lower than that reported in the reference cohort (58%). There were no distal anastomotic new entry tears. Technical success was achieved in 99% of patients. Early remodeling indicated total aortic diameter stability, true lumen expansion, and false lumen reduction in the treated aortic segment.

CONCLUSIONS

Early results show significant reductions in major adverse events and distal anastomotic new entry tears, successfully meeting both primary endpoints. The technical success rate was high. AMDS can be used safely in patients with ADTI dissection with malperfusion.

Technical Aspects of Exclusive Transfemoral Route for Total Endovascular Arch Repair: A Custom-Made Device With Only Upward-Facing Inner Branches for Aortic Arch Treatment

PURPOSE

The purpose was to demonstrate a new arch endograft configuration to allow total endovascular aortic arch repair exclusive from transfemoral approach.

TECHNIQUE

The custom-made multi-branched arch endograft (Cook Medical, Bloomington, Indiana) features 3 inner branches (IBs) for supra-aortic vessels incorporation and complete endovascular arch repair. Traditionally, the innominate and left carotid branches are anterograde IBs, requiring upper access for incorporation of these vessels, and the left subclavian branch is an upward-facing IB that can be incorporated from transfemoral access. We report a novel device configuration with only upward-facing IBs, allowing exclusive transfemoral route for total endovascular arch repair. Technical aspects, implantation technique, and limitations are described thoroughly.

CONCLUSION

Herein is described an arch endograft configuration that simplifies endovascular aortic arch repair, allowing supra-aortic vessel incorporation through a transfemoral route only. This innovative design may serve as another alternative in selected patients.

CLINICAL IMPACT

This innovative endograft design, with only upward-facing inner branches, simplifies the total endovascular aortic arch repair by allowing for a exclusively transfemoral approach. This may reduce procedural complexity and minimizes risks associated with multiple access points. It provides another alternative, particularly beneficial for selected high-risk patients for open repair, potentially expanding the applicability of endovascular treatments for aortic arch pathologies.

The optimal degree of core temperature for hypothermic circulatory arrest in complex aortic arch surgery: results from 1310 patients

OBJECTIVES

The optimal core temperature for hypothermic circulatory arrest during aortic arch surgery remains contentious. This study aims to evaluate patient outcomes under various temperatures within a large single-centre cohort.

METHODS

Between 2010 and 2018, patients diagnosed with type A aortic dissection underwent total arch replacement at Fuwai Hospital were enrolled. They were categorized into 4 groups: deep hypothermia group, low-moderate hypothermia group, high-moderate hypothermia group and mild hypothermia group. Clinical data were analysed to ascertain differences between the groups.

RESULTS

A total of 1310 patients were included in this cohort. Operative mortality stood at 6.9% (90/1310), with a higher incidence observed in the deep hypothermia group [29 (12.9%); 35 (6.9%); 21 (4.8%); 5 (3.4%); all adjusted P < 0.05]. Overall 10-year survival was 80.3%. Long-term outcomes did not significantly differ among the groups. Multivariable logistic analysis revealed a protective effect of higher core temperature on operative mortality (odds ratio 0.848, 95% confidence interval 0.766-0.939; P = 0.001). High-moderate hypothermia emerged as an independent protective factor for operative mortality (odds ratio 0.303, 95% confidence interval 0.126-0.727; P = 0.007). Multivariable Cox analysis did not detect an effect of hypothermic circulatory arrest on long-term survival (all P > 0.05).

CONCLUSIONS

High-moderate hypothermia (24.1-28°C) offers the most effective protection against surgical mortality and is therefore recommended. Different hypothermic circulatory arrest temperatures do not influence long-term survival or quality of life.

Association of triglyceride-glucose index with the risk of incident aortic dissection and aneurysm: a large-scale prospective cohort study in UK Biobank

BACKGROUND

Triglyceride-glucose (TyG) index is an emerging surrogate indicator of insulin resistance, which has been demonstrated as a risk factor for various cardiovascular diseases including coronary syndrome, in-stent restenosis, and heart failure. However, association of TyG index with incident aortic dissection (AD) and aortic aneurysm (AA) remains to be investigated.

METHODS

This study included 420,292 participants without baseline AD/AA from the large-scale prospective UK Biobank cohort. The primary outcome was incident AD/AA, comprising AD and AA. Multivariable-adjusted Cox proportional hazards regression models and restricted cubic spline (RCS) analyses were applied to assess the relationship between TyG index and the onset of AD/AA. In addition, the association between TyG index and incident AD/AA was examined within subgroups defined by age, gender, smoking status, drinking status, diabetes, hypertension, and BMI.

RESULTS

Over a median follow-up period of 14.8 (14.1, 15.5) years, 3,481 AD/AA cases occurred. The incidence of AD/AA rose along with elevated TyG index. RCS curves showed a linear trend of TyG index with risk of incident AD/AA. TyG index was positively associated with risk of incident AD/AA after adjusting for age, gender, smoking status, drinking status, BMI, hypertension, LDL-c, and HbA1c, with adjusted HRs of 1.0 (reference), 1.20 (95% CI 1.08-1.35), 1.21 (95% CI 1.08-1.35), and 1.30 (95% CI 1.16-1.45) for TyG index quartiles 2, 3, and 4, respectively. Especially, participants in the highest TyG index quartile had highest risk of developing AA, with an adjusted HR of 1.35 (95% CI 1.20-1.52).

CONCLUSIONS

TyG index is independently associated with a higher risk of incident AD/AA, indicating the importance of using TyG index for risk assessment of AD/AA, especially for AA.

Inequalities for women diagnosed with distal arch and descending thoracic aortic aneurysms: results from the Effective Treatments for Thoracic Aortic Aneurysms (ETTAA) cohort study

BACKGROUND

Women with thoracic aortic aneurysms within the arch or descending thoracic aorta have poorer survival than men. Sex differences in relative thoracic aortic aneurysm size may account for some of the discrepancy. The aim of this study was to explore whether basing clinical management on aneurysm size index (maximum aneurysm diameter/body surface area) rather than aneurysm size can restore equality of survival by sex.

METHODS

The Effective Treatments for Thoracic Aortic Aneurysms (ETTAA; ISRCTN04044627) study was a prospective, observational cohort study. Adults referred to National Health Service hospitals in England with new/existing arch or descending thoracic aorta aneurysms greater than or equal to 4 cm in diameter were followed from March 2014 to March 2022. Baseline characteristics and survival to intervention and overall were compared for men and women. Survival models were used to assess the association between all-cause survival and sex, with and without adjustment for aneurysm diameter or aneurysm size index.

RESULTS

A total of 886 thoracic aortic aneurysm patients were recruited: 321 (36.2%) women and 565 (63.8%) men. The mean(s.d.) aneurysm diameter was the same for women and men (5.7(1.1) versus 5.7(1.2) cm respectively; P = 0.751), but the mean(s.d.) aneurysm size index was greater for women than for men (3.32(0.80) versus 2.83(0.63) respectively; P < 0.001). Women had significantly worse survival without intervention: 110 (34.3%) women and 135 (23.9%) men (log rank test, P < 0.001). All-cause mortality remained greater for women after adjustment for diameter (HR 1.65 (95% c.i. 1.35 to 2.02); P < 0.001), but was attenuated after adjustment for aneurysm size index (HR 1.11 (95% c.i. 0.89 to 1.38); P = 0.359). Similar results were found for all follow-up, with or without intervention, and findings were consistent for descending thoracic aorta aneurysms alone.

CONCLUSION

Guidelines for referral to specialist services should consider including aneurysm size index rather than diameter to reduce inequity due to patient sex.

Causal Relationships between Lipid-Lowering Drug Target and Aortic Disease and Calcific Aortic Valve Stenosis: A Two-Sample Mendelian Randomization

Background

Proprotein convertase subtilisin/kexin type 9 (PCSK9), 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR), cholesteryl ester transfer protein (CETP) and apolipoprotein C3 (APOC3) are pivotal regulators of lipid metabolism, with licensed drugs targeting these genes. The use of lipid-lowering therapy via the inhibition of these genes has demonstrated a reduction in the risk of cardiovascular disease. However, concerns persist regarding their potential long-term impact on aortic diseases and calcific aortic valve disease (CAVS). This study aims to investigate causal relationships between genetic variants resembling these genes and aortic disease, as well as calcific aortic valve disease using Mendelian randomization (MR).

Methods

We conducted drug-target Mendelian randomization employing summary-level statistics of low-density lipoprotein cholesterol (LDL-C) to proxy the loss-of-function of PCSK9, HMGCR, CETP and APOC3. Subsequently, we investigated the association between drug-target genetic variants and calcific aortic valve stenosis and aortic diseases, including thoracic aortic aneurysm (TAA), abdominal aortic aneurysm (AAA), and aortic dissection (AD).

Results

The genetically constructed variants mimicking lower LDL-C levels were associated with a decreased risk of coronary artery disease, validating their reliability. Notably, HMGCR inhibition exhibited a robust protective effect against TAA (odds ratio (OR): 0.556, 95% CI: 0.372-0.831, p = 0.004), AAA (OR: 0.202, 95% CI: 0.107-0.315, p = 4.84 × 10-15), and AD (OR: 0.217, 95% CI: 0.098-0.480, p = 0.0002). Similarly, PCSK9, CETP and APOC3 inhibition proxies reduced the risk of AAA (OR: 0.595, 95% CI: 0.485-0.730, p = 6.75 × 10-7, OR: 0.127, 95% CI: 0.066-0.243, p = 4.42 × 10-10, and OR: 0.387, 95% CI: 0.182-0.824, p = 0.014, respectively) while showing a neutral impact on TAA and AD. Inhibition of HMGCR, PCSK9, and APOC3 showed promising potential in preventing CAVS with odds ratios of 0.554 (OR: 0.554, 95% CI: 0.433-0.707, p = 2.27 × 10-6), 0.717 (95% CI: 0.635-0.810, p = 9.28 × 10-8), and 0.540 (95% CI: 0.351-0.829, p = 0.005), respectively. However, CETP inhibition did not demonstrate any significant benefits in preventing CAVS (95% CI: 0.704-1.544, p = 0.836). The consistency of these findings across various Mendelian randomization methods, accounting for different assumptions concerning genetic pleiotropy, enhances the causal inference.

Conclusions

Our MR analysis reveals that genetic variants resembling statin administration are associated with a reduced risk of AAA, TAA, AD and CAVS. HMGCR, PCSK9 and APOC3 inhibitors but not CETP inhibitors have positive benefits of reduced CAVS. Notably, PCSK9, CETP and APOC3 inhibitors exhibit a protective impact, primarily against AAA, with no discernible benefits extending to TAA or AD.

Unleashing PD-1: a duel of immunity in aortic aneurysm formation

Aortic aneurysms, particularly abdominal aortic aneurysms (AAAs), exhibit sex differences, with higher prevalence and severity in males than females, both in humans and experimental mouse models. In fact, male sex has been considered as the most potent nonmodifiable risk factor for AAA. Currently, there are no medications approved for the treatment of aortic aneurysms, despite the high lethality of ruptured aneurysms, which account for nearly 2% of all deaths. Moreover, the underlying molecular mechanisms mediating the sexual dimorphism of aortic aneurysms remain largely unknown. In this issue of the JCI, Mu et al. revealed a mechanism by which androgens, male sex hormones, exacerbate aortic aneurysms by suppressing programmed cell death protein 1 (PD-1) expression in T cells in an aldosterone and high salt-induced aortic aneurysm mouse model.

Considering Adverse Effects of Common Antihypertensive Medications in the ED

PURPOSE OF REVIEW

To evaluate the adverse effects of common antihypertensive agents utilized or encountered in the Emergency Department.

RECENT FINDINGS

All categories of antihypertensive agents may manifest adverse effects, inclusive of adverse drug reactions (ADRs), drug-to-drug interactions, or accidental overdose. Adverse effects, and specifically ADRs, may be stratified into the organ systems affected, might require specific time-sensitive interventions, could pose particular risks to vulnerable populations, and may result in significant morbidity, and potential mortality. Adverse effects of common antihypertensive agents may be encountered in the ED, necessitating that ED systems of care are poised to prevent, recognize, and intervene when adverse effects arise.