Management of acute aortic syndrome

miR-485-3p targets SIRT1 in vascular smooth muscle cells mediating the occurrence of aortic dissection

Studies have demonstrated a close correlation between MicroRNA and the occurrence of aortic dissection (AD). However, the molecular mechanisms underlying this relationship have not been fully elucidated and further exploration is still required. In this study, we found that miR-485-3p was significantly upregulated in human aortic dissection tissues. Meanwhile, we constructed in vitro AD models in HAVSMCs, HAECs and HAFs and found that the expression of miR-485-3p was increased only in HAVSMCs. Overexpression or knockdown of miR-485-3p in HAVSMCs could regulate the expression of inflammatory cytokines IL1β, IL6, TNF-α, and NLRP3, as well as the expression of apoptosis-related proteins BAX/BCL2 and Cleaved caspase3/Caspase3. In the in vivo AD model, we have observed that miR-485-3p regulates vascular inflammation and apoptosis, thereby participating in the modulation of AD development in mice. Based on target gene prediction, we have validated that SIRT1 is a downstream target gene of miR-485-3p. Furthermore, by administering SIRT1 agonists and inhibitors to mice, we observed that the activation of SIRT1 alleviates vascular inflammation and apoptosis, subsequently reducing the incidence of AD. Additionally, functional reversal experiments revealed that overexpression of SIRT1 in HAVSMCs could reverse the cell inflammation and apoptosis mediated by miR-485-3p. Therefore, our research suggests that miR-485-3p can aggravate inflammation and apoptosis in vascular smooth muscle cells by suppressing the expression of SIRT1, thereby promoting the progression of aortic dissection.

Histone deacetylase 9-mediated phenotypic transformation of vascular smooth muscle cells is a potential target for treating aortic aneurysm/dissection

Aortic aneurysm/dissection (AAD) is a serious cardiovascular condition characterized by rapid onset and high mortality rates. Currently, no effective drug treatment options are known for AAD. AAD pathogenesis is associated with the phenotypic transformation and abnormal proliferation of vascular smooth muscle cells (VSMCs). However, endogenous factors that contribute to AAD progression remain unclear. We aimed to investigate the role of histone deacetylase 9 (HDAC9) in AAD pathogenesis. HDAC9 expression was considerably increased in human thoracic aortic dissection specimens. Using RNA-sequencing (RNA-seq) and chromatin immunoprecipitation, we demonstrated that HDAC9 transcriptionally inhibited the expression of superoxide dismutase 2 and insulin-like growth factor-binding protein-3, which are critically involved in various signaling pathways. Furthermore, HDAC9 triggered the transformation of VSMCs from a systolic to synthetic phenotype, increasing their proliferation and migration abilities and suppressing their apoptosis. Consistent with these results, in vivo experiments revealed that TMP195, a pharmacological inhibitor of HDAC9, suppressed the formation of the β-aminopropionitrile-induced AAD phenotype in mice. Our findings indicate that HDAC9 may be a novel endogenous risk factor that promotes the onset of AAD by mediating the phenotypic transformation of VSMCs. Therefore, HDAC9 may serve as a potential therapeutic target for drug-based AAD treatment. Furthermore, TMP195 holds potential as a therapeutic agent for AAD treatment.

Chinese Additive Anti-inflammatory Action for Aortopathy & Arteriopathy (5A) Registry protocol: rationale, design and methodology

BACKGROUND

Acute aortic syndrome (AAS) is a life-threatening condition. Inflammation plays a key role in the pathogenesis, development and progression of AAS, and is associated with significant mortality and morbidity. Understanding the inflammatory responses and inflammation resolutions is essential for an appropriate management of AAS.

METHOD

Thirty Chinese cardiovascular centers have collaborated to create a multicenter observational registry (named Chinese Additive Anti-inflammatory Action for Aortopathy & Arteriopathy [5A] registry), with consecutive enrollment of adult patients who underwent surgery for AAS that was started on Jan 1, 2016 and will be ended on December 31, 2040. Specially, the impact of inflammation and anti-inflammatory strategies on the early and late adverse events are investigated. Primary outcomes are severe systemic inflammatory response syndrome (SIRS), multiple organ dysfunction syndrome (MODS), Sequential Organ Failure Assessment (SOFA) scores at 7 days following this current surgery. Secondary outcomes are SISR, 30-day mortality, operative mortality, hospital mortality, new-onset stroke, acute kidney injury, surgical site infection, reoperation for bleeding, blood transfusion and length of stay in the intensive care unit.

DISCUSSION

The analysis of this multicenter registry will allow our better knowledge of the prognostic importance of preoperative inflammation and different anti-inflammatory strategies in adverse events after surgery for AAS. This registry is expected to provide insights into novel different inflammatory resolutions in management of AAS beyond conventional surgical repair.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04398992 (Initial Release: 05/19/2020).

The Role of Trace Elements in Cardiovascular Diseases

Essential trace elements play an important role in human physiology and are associated with various functions regulating cellular metabolism. Non-essential trace elements, on the other hand, often have well-documented toxicities that are dangerous for the initiation and development of diseases due to their widespread occurrence in the environment and their accumulation in living organisms. Non-essential trace elements are therefore regarded as serious environmental hazards that are harmful to health even in low concentrations. Many representatives of these elements are present as pollutants in our environment, and many people may be exposed to significant amounts of these substances over the course of their lives. Among the most common non-essential trace elements are heavy metals, which are also associated with acute poisoning in humans. When these elements accumulate in the body over years of chronic exposure, they often cause severe health damage in a variety of tissues and organs. In this review article, the role of selected essential and non-essential trace elements and their role in the development of exemplary pathophysiological processes in the cardiovascular system will be examined in more detail.

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.

Gut Microbiota-Derived Tryptophan Metabolite Indole-3-aldehyde Ameliorates Aortic Dissection

Tryptophan, an essential dietary amino acid, is metabolized into various metabolites within both gut microbiota and tissue cells. These metabolites have demonstrated potential associations with panvascular diseases. However, the specific relationship between tryptophan metabolism, particularly Indole-3-aldehyde (3-IAId), and the occurrence of aortic dissection (AD) remains unclear. 3-IAId showed an inverse association with advanced atherosclerosis, a risk factor for AD. In this study, we employed a well-established β-aminopropionitrile monofumarate (BAPN)-induced AD murine model to investigate the impact of 3-IAId treatment on the progression of AD. Our results reveal compelling evidence that the administration of 3-IAId significantly mitigated aortic dissection and rupture rates (BAPN + 3-IAId vs. BAPN, 45% vs. 90%) and led to a notable reduction in mortality rates (BAPN + 3-IAId vs. BAPN, 20% vs. 55%). Furthermore, our study elucidates that 3-IAId exerts its beneficial effects by inhibiting the phenotype transition of vascular smooth muscle cells (VSMCs) from a contractile to a synthetic state. It also mitigates extracellular matrix degradation, attenuates macrophage infiltration, and suppresses the expression of inflammatory cytokines, collectively contributing to the attenuation of AD development. Our findings underscore the potential of 3-IAId as a promising intervention strategy for the prevention of thoracic aortic dissection, thus providing valuable insights into the realm of vascular disease management.

Aortic Dissection Detection Risk Score and D-Dimer for Acute Aortic Syndromes in the Chinese Population: Exploration of Optimal Thresholds and Integrated Diagnostic Value

This study aimed to assess the diagnostic performance of the aortic dissection detection risk score (ADD-RS) plus D-dimer for acute aortic syndrome (AAS) in Chinese patients. Two hundred and sixty-two and 200 patients with suspected AAS symptoms were enrolled as exploration cohort and validation cohort, respectively. In exploration cohort, ADD-RS plus D-dimer (AUC = 0.929, 95%CI: 0.887-0.971) presented a better diagnostic value for AAS than ADD-RS or D-dimer alone. Meanwhile, ADD-RS > 1 and D-dimer > 2000 ng/mL were the optimal thresholds. Then, a diagnostic model integrating ADD-RS > 1 plus D-dimer > 2000 ng/mL was established, presenting sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 92.5%, 70.3%, 34.9%, and 98.2%, respectively. In validation cohort, the established diagnostic model exhibited a sensitivity, specificity, PPV, and NPV of 93.1%, 70.2%, 34.6%, and 98.4%, respectively, for diagnosing AAS. Summarily, ADD-RS > 1 and D-dimer > 2000 ng/mL are optimal thresholds for diagnosing AAS in the Chinese population. However, confirmative MSCT results are necessary.

Low Zinc Alleviates the Progression of Thoracic Aortic Dissection by Inhibiting Inflammation

Vascular inflammation triggers the development of thoracic aortic dissection (TAD). Zinc deficiency could dampen tissue inflammation. However, the role of zinc as a nutritional intervention in the progression of TAD remains elusive. In this study, we employed a classical β-aminopropionitrile monofumarate (BAPN)-induced TAD model in mice treated with low zinc and observed that the TAD progression was greatly ameliorated under low zinc conditions. Our results showed that low zinc could significantly improve aortic dissection and rupture (BAPN + low zinc vs. BAPN, 36% vs. 100%) and reduce mortality (BAPN + low zinc vs. BAPN, 22% vs. 57%). Mechanically, low zinc attenuated the infiltration of macrophages and inhibited the expression of inflammatory cytokines, suppressed the phenotype switch of vascular smooth muscle cells from contractile to synthetic types, and eventually alleviated the development of TAD. In conclusion, this study suggested that low zinc may serve as a potential nutritional intervention approach for TAD prevention.

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.

The role of peripheral blood eosinophil counts in acute Stanford type A aortic dissection patients

Background

Acute Stanford-A aortic dissection (AAAD) is a devastating cardiovascular condition with high mortality, therefore identifying risk prognosis factors is vital for the risk stratification of patients with AAAD. Here, we investigated peripheral blood eosinophil (EOS) counts in patients with AAAD and their possible biological implications.

Methods

We performed a single center retrospective cohort study. From 2011 to 2021, a total of 1,190 patients underwent AAAD surgery. Patients were categorized first by death and then admission EOS counts (0.00 × 109/L or >0.00 × 109/L). Demographics, laboratory data, and outcomes were analyzed using standard statistical analyses. Ascending aorta specimens were used for western blotting and histological assessments.

Results

Death group patients had lower EOS counts than the non-death group (P = 0.008). When patients were stratified using mean blood EOS counts: 681 patients had low (0.00 × 109/L) and 499 had high (>0.00 × 109/L) counts. Patients with low EOS counts at admission were more likely to have a higher mortality risk (P = 0.017) and longer treatment in the intensive care unit (ICU) days (P = 0.033) than patients with normal EOS counts. Also, the five blood coagulation items between both groups showed significantly different (P < 0.001). Hematoxylin & eosin-stained cross-sections of the ascending aorta false lumen showed that EOSs were readily observed in thrombi in the false lumen of the aorta.

Conclusions

Peripheral blood EOS counts may be involved in thrombosis and could be an effective and efficient indicator for the diagnosis, evaluation, and prognosis monitoring of patients with AAAD.

Emergent Magnetic Resonance Angiography for Evaluation of the Thoracoabdominal and Peripheral Vasculature

Thoracoabdominal and peripheral vasculature pathologies include a variety of severe and life threatening conditions that may be encountered in the emergent setting. Computed tomography angiography (CTA) is the first-line modality for imaging of the vasculature in this context, but magnetic resonance angiography (MRA) also plays an important and emerging role in the evaluation of carefully selected patients. Intravenous (IV) iodinated contrast is necessary for CTA, although MRA is most useful in patients who cannot receive IV iodinated contrast for reasons including prior severe allergic-like reaction to iodinated contrast, poor IV access, or severe renal insufficiency. Gadolinium-based contrast agents are administered for MRA when possible, as they generally improve the diagnostic quality and shorten the duration of the exam. In most clinical situations, however, noncontrast MRA is sufficient to obtain a diagnostic evaluation. In this review, we discuss the key strengths and limitations of MRA performed in the emergent setting, highlighting the role of MRA in the diagnosis of acute aortic syndromes, aortitis, aortic aneurysm, pulmonary embolism, and peripheral vascular disease.

Identification of Immune-Related Gene Signature in Stanford Type A Aortic Dissection

Background: Stanford type A aortic dissection (ATAAD) is a common life-threatening event in the aorta. Recently, immune disorder has been linked to the risk factors that cause ATAAD at the molecular level. However, the specific immune-related gene signature during the progression is unclear.

Methods: The GSE52093 and GSE98770 datasets related to ATAAD from the Gene Expression Omnibus (GEO) database were acquired. The immune gene expression levels were analyzed by single sample gene set enrichment analysis (ssGSEA). The correlations between gene networks and immune scores were determined by weighted gene correlation network analysis (WGCNA). The different immune subgroups were finally divided by consensus clustering. The differentially expressed genes (DEGs) were identified and subsequent functional enrichment analyses were conducted. The hub genes were identified by protein–protein interaction (PPI) network and functional similarities analyses. The immune cell infiltration proportion was determined by the CIBERSORT algorithm.

Results: According to the ssGSEA results, the 13 ATAAD samples from the GEO database were divided into high- and low-immune subgroups according to the ssGSEA, WGCNA, and consensus clustering analysis results. Sixty-eight immune-related DEGs (IRDEGs) between the two subgroups were enriched in inflammatory-immune response biological processes, including leukocyte cell–cell adhesion, mononuclear cell migration, and myeloid leukocyte migration. Among these IRDEGs, 8 genes (CXCR4, LYN, CCL19, CCL3L3, SELL, F11R, DPP4, and VAV3) were identified as hub genes that represented immune-related signatures in ATAAD after the PPI and functional similarities analyses. The proportions of infiltrating CD8 T cells and M1 macrophages were significantly higher in ATAAD patients in the immune-high group than the immune-low group.

Conclusion: Eight immune-related genes were identified as hub genes representing potential biomarkers and therapeutic targets linked to the immune response in ATAAD patients.

Development and Validation of a Prognostic Model to Predict the Risk of In-hospital Death in Patients With Acute Kidney Injury Undergoing Continuous Renal Replacement Therapy After Acute Type a Aortic Dissection

Background

This study aimed to construct a model to predict the risk of in-hospital death in patients with acute renal injury (AKI) receiving continuous renal replacement therapy (CRRT) after acute type A aortic dissection (ATAAD) surgery.

Methods

We reviewed the data of patients with AKI undergoing CRRT after ATAAD surgery. The patients were divided into survival and nonsurvival groups based on their vital status at hospital discharge. The data were analyzed using univariate and multivariate logistic regression analyses. Establish a risk prediction model using a nomogram and its discriminative ability was validated using C statistic and the receiver operating characteristic (ROC) curve. Its calibration ability was tested using a calibration curve, 10-fold cross-validation and Hosmer–Lemeshow test.

Results

Among 175 patients, in-hospital death occurred in 61 (34.9%) patients. The following variables were incorporated in predicting in-hospital death: age > 65 years, lactic acid 12 h after CRRT, liver dysfunction, and permanent neurological dysfunction. The risk model revealed good discrimination (C statistic = 0.868, 95% CI: 0.806–0.930; a bootstrap-corrected C statistic of 0.859, the area under the ROC = 0.868). The calibration curve showed good consistency between predicted and actual probabilities (via 1,000 bootstrap samples, mean absolute error = 2.2%; Hosmer–Lemeshow test, P = 0.846). The 10-fold cross validation of the nomogram showed that the average misdiagnosis rate was 16.64%.

Conclusion

The proposed model could be used to predict the probability of in-hospital death in patients undergoing CRRT for AKI after ATAAD surgery. It had the potential to assist doctors to identify the gravity of the situation and make the targeted therapeutic measures.

Anterior STEMI complicating acute aortic syndrome: mechanistic insight and bridge to surgery with intravascular ultrasound-guided primary PCI

Stanford type A acute aortic syndromes (AAS) can be complicated with acute coronary closure and ST segment elevation myocardial infarction (STEMI) leading to significant additional morbidity and mortality. The recommended treatment for type A AAS is emergency cardiac surgery. We present the case of a patient with intramural haematoma involving the ascending and descending aorta complicated with anterior wall STEMI after CT imaging. Coronary angiography and intravascular ultrasonography (IVUS) revealed the dissection spiralling into the media of the left main stem (LMS) and left anterior descending (LAD) coronary artery. In the setting of acute vessel closure and ongoing myocardial ischaemia primary percutaneous coronary intervention (PCI) was performed to the LMS, LAD and second diagonal branch prior to successful emergency cardiac surgery with an aortic-arch interposition graft. Emergency IVUS-guided stenting to relieve acute coronary occlusion in the context of aortic dissection can be performed in selected cases to safely bridge the patient for cardiac surgery.

β-Aminopropionitrile-induced aortic aneurysm and dissection in mice

The mechanistic basis for the formation of aortic aneurysms and dissection needs to be elucidated to facilitate the development of effective medications. β-Aminopropionitrile administration in mice has been used frequently to study the pathologic features and mechanisms of aortic aneurysm and dissection. This mouse model mimics several facets of the pathology of human aortic aneurysms and dissection, although many variables exist in the experimental design and protocols that must be resolved to determine its application to the human disease. In the present brief review, we have introduced the development of this mouse model and provided insights into understanding its pathologic features.

Low ambient temperature and temperature drop between neighbouring days and acute aortic dissection: a case-crossover study

AIMS

The incidence of acute aortic dissection (AAD) has been shown to have seasonal variation, but whether this variation can be explained by non-optimum ambient temperature and temperature change between neighbouring days (TCN) is not clear.

METHODS AND RESULTS

We performed a time-stratified case-crossover study in the Registry of Aortic Dissection in China covering 14 tertiary hospitals in 11 cities from 2009 to 2019. A total of 8182 cases of AAD were included. Weather data at residential address were matched from nearby monitoring stations. Conditional logistic regression model and distributed lag nonlinear model were used to estimate the associations of daily temperature and TCN with AAD, adjusting for possible confounders. We observed an increase of AAD risk with lower temperature cumulated over lag 0-1 day and this association became statistically significant when daily mean temperature was below 24°C. Relative to the referent temperature (28°C), the odds ratios (ORs) of AAD onset at extremely low (-10°C) and low (1°C) temperature cumulated over lag 0-1 day were 2.84 [95% confidence interval (CI): 1.69, 4.75] and 2.36 (95% CI: 1.61, 3.47), respectively. A negative TCN was associated with increased risk of AAD. The OR of AAD cumulated over lag 0-6 days was 2.66 (95% CI: 1.76, 4.02) comparing the extremely negative TCN (-7°C) to no temperature change. In contrast, a positive TCN was associated with reduced AAD risk.

CONCLUSION

This study provides novel and robust evidence that low ambient temperature and temperature drop between neighbouring days were associated with increased risk of AAD onset.

KEY QUESTION

Incidence of acute aortic dissection (AAD) was reported to have seasonal trends, but it remains unclear whether non-optimum ambient temperature and temperature change between neighbouring days (TCN) is associated with AAD onset.

KEY FINDING

Daily mean temperature lower than 24°C was significantly associated with increased risk of AAD at lag 0-1 day. A negative TCN (temperature drop) was associated with increased risk of AAD, whereas a positive TCN was associated with decreased risk.

TAKE HOME MESSAGE

This multi-centre, case-crossover study provides novel and robust evidence that low ambient temperature and temperature drop between neighbouring days were associated with increased AAD risk.

circ_TGFBR2 Inhibits Vascular Smooth Muscle Cells Phenotypic Switch and Suppresses Aortic Dissection Progression by Sponging miR-29a

Background

Aortic dissection (AD) is a threatening and catastrophic vascular disease with high mortality rate and limited therapeutic strategies. There is emerging evidence showing that circular RNAs play crucial role in regulating various cardiovascular diseases. However, the biological functions and molecular mechanisms of circRNAs in AD still remains elusive. The purpose of this study was to illustrate the potential functional roles and mechanisms of hsa_circ_TGFBR2 in vitro and in vivo.

Methods

The vascular smooth muscle cells (VSMCs) and AD-VSMCs were isolated from normal aorta and AD tissues. The expression of circ_TGFBR2, miR-29a and KLF4 were detected by realtime polymerase chain reaction (RT-PCR) and fluorescence in situ hybridization (FISH). Cell proliferation was assessed by CCK-8 assay, colony formation and EDU assay. Cell migration was evaluated through transwell assay. Dual-luciferase reporter assay and RNA pulldown were performed to identify the interaction between circ_TGFBR2 and miR-29a or between miR-29a and KLF4. The wild-type sequence of circ_TGFBR2 or KLF4 were cloned into the luciferase reporter plasmid, and the activity was measured using dual-luciferase reporter assay system. And for RNA pulldown, the relative RNA enrichment of circ_TGFBR2 and miR-29a were confirmed using RT-PCR. Western Blot measured the expression of phenotype switch-related proteins. AD rat model induced by β-aminopropionitrile monofumarate (BAPN) was used to verify the role and mechanism of circ_TGFBR2.

Results

Circ_TGFBR2 inhibited cell proliferation and migration of AD-VSMCs cells. Overexpression of circ_TGFBR2 promoted the expression of contractile markers (α-SMA, SM22α) and inhibited the expression of synthetic markers (MGP, OPN) in AD-VSMCs cells. Circ_TGFBR2 served as a sponge for miR-29a targeting KLF4. MiR-29a mimics rescued biological roles induced by circ_TGFBR2 overexpression. The in vivo experiments revealed that overexpression of TGFBR2 suppressed the progression of AD and increased the expression of contractile markers while inhibited the expression of synthetic markers.

Conclusion

Our study revealed that circ_TGFBR2 regulated VSMCs phenotype switch and suppressed the progression of AD.

Integration of multiple imaging platforms to uncover cardiovascular defects in adult zebrafish

Aims

Mammalian models have been instrumental in investigating adult heart function and human disease. However, electrophysiological differences with human hearts and high costs motivate the need for non-mammalian models. The zebrafish is a well-established genetic model to study cardiovascular development and function; however, analysis of cardiovascular phenotypes in adult specimens is particularly challenging as they are opaque.

Methods and results

Here, we optimized and combined multiple imaging techniques including echocardiography, magnetic resonance imaging, and micro-computed tomography to identify and analyse cardiovascular phenotypes in adult zebrafish. Using alk5a/tgfbr1a mutants as a case study, we observed morphological and functional cardiovascular defects that were undetected with conventional approaches. Correlation analysis of multiple parameters revealed an association between haemodynamic defects and structural alterations of the heart, as observed clinically.

Conclusion

We report a new, comprehensive, and sensitive platform to identify otherwise indiscernible cardiovascular phenotypes in adult zebrafish.

Ethnic differences in incidence and outcomes of acute aortic syndromes in the Midland region of New Zealand

BACKGROUND

Disparities in cardiovascular disease according to socioeconomic factors and ethnicity are a global issue. The indigenous Māori population of New Zealand is not exempt. The aims of the present study were to assess whether ethnic disparities exist in the presentation and outcomes of acute aortic syndrome (AAS), including aortic dissection, intramural hematoma, and penetrating aortic ulcer, in New Zealand.

METHODS

A retrospective observational cohort study of consecutive AAS patients presenting to a tertiary referral center covering the Midland region of New Zealand (population, 816,900; 23.3% Māori) during a 10-year period was completed (2010-2020). Data were assessed by ethnicity (Māori vs non-Māori) and Stanford classification of AAS. The incidence of disease, 30-day mortality, and long-term all-cause and aortic-related mortality were recorded and assessed using logistic regression and Cox proportional hazards models.

RESULTS

A total of 250 patients had presented with AAS (Māori, 92 [36.8%]; type A, 144 [57.6%]). The age-standardized rates of AAS were higher in Māori than in non-Māori patients (6.9/100,000 person-years vs 2.0/100,000 person-years; risk ratio, 3.56; 95% confidence interval, 1.50-8.53; P = .002). Māori patients had presented at a younger age for both type A (age, 54.4 ± 12 years vs 66.0 ± 13.2 years; P < .001) and type B (age, 61.3 ± 10.2 years vs 68.8 ± 13.7 years; P = .005) AAS. Mortality at 30 days was higher for those with type A than for those with type B AAS (33.3% vs 13.2%; P < .001) but did not differ by ethnicity in our cohort. On multivariate analysis, no differences were found in 30-day or long-term survival when stratified by ethnicity.

CONCLUSIONS

The results from the present study have demonstrated that ethnic disparities in AAS exist in New Zealand, with Māori presenting at a younger age and with a greater incidence compared with other ethnicities. Whether this disparity is related to socioeconomic factors, access to preventive care, or other factors remains to be elucidated. Despite these differences in disease presentation, the survival outcomes when stratified by ethnicity were comparable in the present cohort.

Outflow Through Aortic Side Branches Drives False Lumen Patency in Type B Aortic Dissection

Objective: Thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD) aims to induce false lumen (FL) thrombosis by sealing intimal tears between the true (TL) and the FL, and blocking the inflow into the FL. Incomplete thrombosis of the FL is correlated with poor clinical outcome. We hypothesize that the number of major and minor branches arising from the FL affects FL patency and may negatively influence TEVAR induced FL thrombosis.

Methods: Computed tomography (CT)-scans from 89 patients diagnosed with TBAD [best medical treatment (BMT) n = 52, TEVAR n = 37] from two high-volume vascular surgery centers were analyzed retrospectively. Analysis included evaluation of the FL patency status, the number, location and size of intimal tears, and the presence of minor and major side branches originating from the FL. Multiple regression analysis was conducted to evaluate obtained parameters as predictors for FL thrombosis status.

Results: In univariate analysis, the strongest correlation for FL patency was found for the number of major (R = 0.79) and minor (R = 0.86) side branches originating from the FL. When applying a multiple linear regression model, the number of major (normalized beta 0.37; P < 0.001) and minor (normalized beta 0.41; P < 0.01) side branches arising from the FL were valid predictors for the axial length of the patent and non-patent FL, and additionally determined the length of the patent FL at 12-month follow-up in patients that underwent TEVAR.

Conclusions: Our data suggest that the number of minor side branches that originate from the FL in TBAD is an important determinant of FL patency, to a greater degree than previously assumed.

The Aortic Pathologies: How Far We Understand It and Its Implications on Thoracic Aortic Surgery

Thoracic aortic diseases contribute to a major part of cardiac surgeries. The severity of pathologies varies significantly from emergency and life-threatening to conservatively managed conditions. Life-threatening conditions include type A aortic dissection and rupture. Aortic aneurysm is an example of a conservatively managed condition. Pathologies that affect the arterial wall can have a profound impact on the presentation of such cases. Several risk factors have been identified that increase the risk of emergency presentations such as connective tissue disease, hypertension, and vasculitis. The understanding of aortic pathologies is essential to improve management and clinical outcomes.

S100A1 as a potential biomarker for the diagnosis of patients with acute aortic dissection

Objective

Acute aortic dissection (AAD) is a common life-threatening cardiovascular disease. This retrospective study was conducted to analyze the plasma concentration of S100A1 and its diagnostic value for AAD through receiver operating characteristic (ROC) curve and logistic regression analyses.

Methods

Seventy-eight patients with AAD and 77 healthy controls were included, and the relevant clinical data for each group were collected. According to the Stanford classification, the AAD patients were divided into types A and B. The plasma levels of S100A1, D-dimer, hypersensitive C-reactive protein, and cardiac troponin T were detected by enzyme-linked immunosorbent assays.

Results

The S100A1 concentrations in the healthy control, Stanford A, and Stanford B groups were 0.7 ± 0.6, 4.9 ± 2.6, and 3.5 ± 2.2 ng/mL, respectively. The concentration of S100A1 was increased in patients with AAD complicated with aortic regurgitation, pericardial effusion, or in-hospital death. ROC curve analysis showed that the area under the curve was 0.89. Logistic regression analysis revealed that the S100A1 level was an important risk factor for the development of AAD.

Conclusion

Plasma S100A1 is significantly elevated in patients with AAD, and its concentration has potential clinical value for diagnosing AAD.

Aortic dissection during pregnancy and postpartum

BACKGROUND

Patients with aortic dissection during pregnancy and postpartum period exhibit a high mortality. At present, a complete overview of aortic dissection during pregnancy and postpartum period is lacking. ​Methods: This systematic review included 80 reports published from 2000 to 2020, comprising a total study population of 103 patients with aortic dissection. ​Results: We found that Stanford Type A aortic dissection was more common in prepartum cases, especially in the third trimester, while postpartum cases of aortic dissection were more common in Stanford Type B. The most common risk factor was connective tissue disease, with no other known risk factors. The mode of delivery had no significant effect on the type of postpartum aortic dissection. Reduced maternal and fetal mortality was observed when patients with Stanford Type A aortic dissection occurring after 28 gestational weeks underwent cesarean section followed by aortic replacement. Patients with Stanford Type B aortic dissection were treated mainly with medication and/or endovascular repair. ​Conclusion: Contemporary management of patients during pregnancy and within 12 weeks postpartum requires multidisciplinary cooperation and includes serial, noninvasive imaging, biomarker testing, and genetic risk profiling for aortopathy. Early diagnosis and accurate treatment are essential to reduce maternal and fetal mortality.

Computed Tomography Angiography Assessment of Acute Aortic Syndromes: Classification, Differentiating Imaging Features, and Imaging Interpretation Pitfalls

An acute aortic syndrome (AAS) is an important life-threatening condition that requires early detection and management. Acute intramural hematoma (IMH), aortic dissection (AD) and penetrating atherosclerotic ulcer (PAU) are included in AAS. ADs can be classified using the well-known Stanford or DeBakey classification systems. However, these classification systems omit description of arch dissections, anatomic variants, and morphologic features that impact outcome. The Society for Vascular Surgery and Society of Thoracic Surgeons (SVS-STS) have recently introduced a classification system that classifies ADs according to the location of the entry tear (primary intimomedial tear, PIT) and the proximal and distal extent of involvement, but does not include description of all morphologic features that may have diagnostic and prognostic significance. This review describes these classification systems for ADs and other AAS entities as well as their limitations. Typical computed tomography angiography (CTA) imaging appearance and differentiating features of ADs, limited intimal tears (LITs), IMHs, intramural blood pools (IBPs), ulcer-like projections (ULPs), and PAUs will be discussed. Furthermore, this review highlights common imaging interpretation pitfalls, what should be included in a comprehensive CTA report, and provides a brief overview of current management options.

Identification of Molecular Regulatory Features and Markers for Acute Type A Aortic Dissection

BACKGROUND

Acute type A aortic dissection (ATAAD) is one of the most lethal cardiovascular diseases, and its molecular mechanism remains unclear.

METHODS

Differentially expressed genes (DEGs) between ATAAD and control were detected by limma R package in GSE52093, GSE153434, GSE98770, and GSE84827, respectively. The coexpression network of DEGs was identified by the WGCNA package. Enrichment analysis was performed for module genes that were positively correlated with ATAAD using clusterProfiler R package. In addition, differentially methylated markers between aortic dissection and control were identified by ChAMP package. After comparing with ATAAD-related genes, a protein-protein interaction (PPI) network was established based on the STRING database. The genes with the highest connectivity were identified as hub genes. Finally, differential immune cell infiltration between ATAAD and control was identified by ssGSEA.

RESULTS

From GSE52093 and GSE153434, 268 module genes were obtained with consistent direction of differential expression and high correlation with ATAAD. They were significantly enriched in T cell activation, HIF-1 signaling pathway, and cell cycle. In addition, 2060 differentially methylated markers were obtained from GSE84827. Among them, 77 methylation markers were ATAAD-related DEGs. Using the PPI network, we identified MYC, ITGA2, RND3, BCL2, and PHLPP2 as hub genes. Finally, we identified significantly differentially infiltrated immune cells in ATAAD.

CONCLUSION

The hub genes we identified may be regulated by methylation and participate in the development of ATAAD through immune inflammation and oxidative stress response. The findings may provide new insights into the molecular mechanisms and therapeutic targets for ATAAD.

Anxa1 in smooth muscle cells protects against acute aortic dissection

AIMS

Acute aortic dissection (AAD) is a life-threatening disease with high morbidity and mortality. Previous studies have showed that vascular smooth muscle cell (VSMC) phenotype switching modulates vascular function and AAD progression. However, whether an endogenous signaling system that protects AAD progression exists, remains unknown. Our aim is to investigate the role of Anxa1 in VSMC phenotype switching and the pathogenesis of AAD.

METHODS AND RESULTS

We first assessed Anxa1 expression levels by immunohistochemical staining in control aorta and AAD tissue from mice. A strong increase of Anxa1 expression was seen in the mouse AAD tissues. In line with these findings, micro-CT scan results indicated that Anxa1 plays a role in the development of AAD in our murine model, with systemic deficiency of Anxa1 markedly progressing AAD. Conversely, administration of Anxa1 mimetic peptide, Ac2-26, rescued the AAD phenotype in Anxa1-/- mice. Transcriptomic studies revealed a novel role for Anxa1 in VSMC phenotype switching, with Anxa1 deficiency triggering the synthetic phenotype of VSMCs via down-regulation of the JunB/MYL9 pathway. The resultant VSMC synthetic phenotype rendered elevated inflammation and enhanced matrix metalloproteinases (MMPs) production, leading to augmented elastin degradation. VSMC-restricted deficiency of Anxa1 in mice phenocopied VSMC phenotype switching and the consequent exacerbation of AAD. Finally, our studies in human AAD aortic specimens recapitulated key findings in murine AAD, specifically that the decrease of Anxa1 is associated with VSMC phenotype switch, heightened inflammation, and enhanced MMP production in human aortas.

CONCLUSIONS

Our findings demonstrated that Anxa1 is a novel endogenous defender that prevents acute aortic dissection by inhibiting vascular smooth muscle cell phenotype switching, suggesting that Anxa1 signaling may be a potential target for AAD pharmacological therapy.

TRANSLATIONAL PERSPECTIVE

Our studies herein may lead to a paradigm shift for pharmacologic therapy towards acute aortic dissection. Through careful examination of the pathological changes that occur during AAD onset in experimental animal models, we demonstrated that VSMC phenotype switching plays a critical role in the development of AAD. Inhibition of VSMC phenotype switching and its attendant impacts on aortic function may be a viable approach for future treatment. Toward that end, our studies highlighted the protective benefit of Anxa1 and its mimetic peptide Ac2-26 in AAD through prevention of the switching of VSMC to a synthetic phenotype.

Early outcomes associated with use of the Zenith TX2 Dissection Endovascular Graft for the treatment of Stanford type B aortic dissection

OBJECTIVE

To evaluate short term outcomes related to the use of the Zenith TX2 Dissection Endovascular Graft (ZDEG) and the Zenith Dissection Bare stent (ZDES) for the treatment of Stanford type B aortic dissections.

METHODS

This retrospective multicenter case cohort study collated data from 10 European institutions for patients with both complicated and uncomplicated type B aortic dissection treated with ZDEG and ZDES between 2011 and 2018. The primary end point was mortality at 30 and 90 days. Secondary end points included complications related to TEVAR, such as, type Ia endoleak, stroke, paraparesis, paraplegia, and retrograde type A dissection (RTAD). Statistical analysis was carried out using the t test, or one-way analysis of variance and the χ² or Fisher exact tests.

RESULTS

We treated 120 patients (87 male; mean age, 62.7 ± 12.2years) either in the acute 76 (63.3%), subacute 16 (13.3%), or chronic 28 (23.3%) phase. Seven patients (5.8%) died within 30 days after the index procedure and two (1.7%) between 30 and 90 days. There was one instance of postoperative RTAD in a patient treated for rupture. Stroke and paraplegia occurred in three (2.5%) and five (4.2%), patients, respectively. Eight patients (6.7%) had a type Ia endoleak in the perioperative period. There were no instances of paraplegia, no permanent dialysis, and no requirement for adjunctive superior mesenteric or celiac artery stenting in the 33 patients (27.5%) who were treated by concurrent placement of ZDES distal to the ZDEG. The length and distal oversizing of ZDEG components used was less in this group.

CONCLUSIONS

The present series demonstrates a low (<1%) RTAD rate and favorable morbidity and mortality. The lower rate of paraplegia, dialysis, and visceral artery stenting in the cohort that had adjunctive use of ZDES is compelling and merits further assessment.

Development of a test method to investigate mode II fracture and dissection of arteries

The current study presents the development and implementation of a bespoke experimental technique to generate and characterise mode II crack initiation and propagation in arterial tissue. The current study begins with a demonstration that lap-shear testing of arterial tissue results in mixed mode fracture, rather than mode II. We perform a detailed computational design of a bespoke experimental method (which we refer to as a shear fracture ring test (SFRT)) to robustly and repeatably generate mode II crack initiation and propagation in arteries. This method is based on generating a localised region of high shear adjacent to a cylindrical loading bar. Placement of a radial notch in this region of high shear stress is predicted to result in a kinking of the crack during a mode II initiation and propagation of the crack over a long distance in the circumferential (c)-direction along the circumferential-axial (c-a) plane. Fabrication and experimental implementation of the SFRT on excised ovine aorta specimens confirms that the bespoke test method results in pure mode II initiation and propagation. We demonstrate that the mode II fracture strength along the c-a plane is eight times higher than the corresponding mode I strength determined from a standard peel test. We also calibrate the mode II fracture energy based on our measurement of crack propagation rates. The mechanisms of fracture uncovered in the current study, along with our quantification of mode II fracture properties have significant implications for current understanding of the biomechanical conditions underlying aortic dissection.

Diagnostic value of monocyte to high-density lipoprotein ratio in acute aortic dissection in a Chinese han population

Background: Recently, considerable evidence pointed out monocyte to high-density lipoprotein ratio (MHR) is highly related to inflammatory related diseases. We aim to explore the level of MHR in acute aortic dissection (AAD) patients and determine whether MHR can be a novel diagnostic marker of AAD. Research design and methods: A total of 228 subjects including 128 AAD patients and 110 healthy control were enrolled. MHR levels and other serum samples were obtained at admission. Results: The baseline MHR levels were significantly higher in patients with AAD (p < 0.0001). A cutoff value of MHR >0.37 was associated with a sensitivity of 86.70% and a specificity of 93.60% for AAD. MHR levels were positively correlated with the time from symptom onset (R² = 0.0318, p = 0.0003). Additionally, the area under the curve (AUC) was increased to 0.979 in patients whose time from onset of symptoms >24 h, with a sensitivity of 98.04% and a specificity of 93.64%. Multivariate logistic regression demonstrated that MHR levels, history of hypertension, and coronary artery disease (CHD) emerged as independent predictors of AAD. Expert Opinion: MHR has a high diagnostic value in AAD patients, especially in those whose time from onset of symptoms >24 h.

Clevidipine as a therapeutic and cost-effective alternative to sodium nitroprusside in patients with acute aortic syndromes

Background:

Sodium nitroprusside is the preferred agent for the treatment of high blood pressure during acute aortic syndrome if blood pressure remains elevated after heart rate control with beta-blockers. The increasing cost of sodium nitroprusside in the USA led us to assess the efficacy and safety of intravenous clevidipine, a calcium channel blocker with quick onset of action, short half-life and significantly lower costs than sodium nitroprusside, in patients presenting with acute aortic syndrome.

Methods:

We performed a retrospective chart review of consecutive patients admitted to the Cleveland Clinic Cardiac Intensive Care Unit from 2013–2016 with a diagnosis of acute aortic syndrome. Patients who received intravenous sodium nitroprusside were compared with those receiving intravenous clevidipine. The primary outcome was a significant difference in blood pressure at one, three and six hours. Secondary outcomes included time to achieving blood pressure target and in hospital mortality with rates of hypotension and bradycardia as safety endpoints.

Results:

A total of 85 patients with suspected acute aortic pathology received clevidipine and 50 received sodium nitroprusside. Clinical and demographic characteristics were similar in both groups, except for a higher incidence of abdominal aortic aneurysm in the clevidipine group and for a trend towards higher use of labetalol in the clevidipine group. There were no significant differences in blood pressure or heart rate at one, three and six hours after starting either infusion. The rates of hypotension, bradycardia and in-hospital mortality did not differ. Time to achieve blood pressure control were also similar between groups.

Conclusion:

Intravenous clevidipine appears to be a safe and effective alternative to sodium nitroprusside for the management of high blood pressure during acute aortic dissection. In the USA, clevidipine could represent a cost effective therapy providing similar outcomes than sodium nitroprusside.

Acute aortic dissection during pregnancy: Trials and tribulations

BACKGROUND

Type A acute aortic dissection (TAAD) during pregnancy is a life-threatening event for both the mother and the unborn baby. Pregnancy has been recognized as an independent risk factor for TAAD, postulated to be due to physiological changes that cause hyperdynamic circulation. This review seeks to outline the current controversies around this unique group.

METHODS

A comprehensive literature search was carried out across large databases to assimilate relevant papers regarding acute aortic dissection in pregnant women.

RESULTS

The presentation can be atypical in many cases and further concern from clinicians of fetal radiation exposure can result in missed or delayed diagnoses. Investigation via the quickest form of imaging, whether computed tomography, magnetic resonance imaging, or transesophageal echocardiography, should be carried out promptly due to the high risk of mortality. Surgical management of TAAD in pregnancy revolves primarily around the decision to deliver the fetus concomitantly or to perform the aortic repair with the fetus in utero.

CONCLUSIONS

Management of this group includes rapid and dynamic assessment without delay. From conception to postpartum, there are multiple stages in which to manage these women. Challenges in carrying out management in the form of operative techniques and cardiopulmonary bypass place the fetus at risk and must be approached with caution, particularly as there is little evidence-base for many of these decisions. Further research into reducing maternal and fetal mortality is necessary.

Perioperative risk factors predict one-year mortality in patients with acute type-A aortic dissection

Objective

The goal of this study was to analyze perioperative risk factors to predict one- year mortality after operation for acute type A aortic dissection (AAD).

Methods

A total of 121 consecutive patients undergoing Stanford type A AAD surgery in Beijing Anzhen Hospital were enrolled. Preoperative clinical and laboratory data from patients were collected.

Results

Multivariable Cox regression analysis showed that significant factors associated with increased one-year mortality were elder age (year) (hazard ratio (HR) 1.0985; 95% confidence interval (CI) 1.0334–1.1677), intraoperative blood transfusion ≥2000 mL (HR 8.8081; 95% CI 2.3319–33.2709), a higher level of serum creatinine (μmol/L) at postoperative one day (HR 1.0122; 95% CI 1.0035–1.0190) and oxygenation index (OI) < 200 (mmHg) at the end of surgery (HR 5.7575; 95% CI 1.1695–28.3458).

Conclusion

In this study, perioperative risk factors to predict one-year prognosis are age, intraoperative blood transfusion ≥2000 mL, postoperative OI < 200 mmHg and level of postoperative serum creatinine. The results aid in the comprehension of surgical outcomes and assist in the optimization of treatment strategies for those with perioperative risk factors to decrease one-year mortality.

Location of Reentry Tears Affects False Lumen Thrombosis in Aortic Dissection Following TEVAR

Purpose: To report a study that assesses the influence of the distance between the distal end of a thoracic stent-graft and the first reentry tear (SG-FRT) on the progression of false lumen (FL) thrombosis in patients who underwent thoracic endovascular aortic repair (TEVAR). Materials and Methods: Three patient-specific geometrical models were reconstructed from postoperative computed tomography scans. Two additional models were created by artificially changing the SG-FRT distance in patients 1 and 2. In all 5 models, computational fluid dynamics simulations coupled with thrombus formation modeling were performed at physiological flow conditions. Predicted FL thrombosis was compared to follow-up scans. Results: There was reduced false lumen flow and low time-averaged wall shear stress (TAWSS) in patients with large SG-FRT distances. Predicted thrombus formation and growth were consistent with follow-up scans for all patients. Reducing the SG-FRT distance by 30 mm in patient 1 increased the flow and time-averaged wall shear stress in the upper abdominal FL, reducing the thrombus volume by 9.6%. Increasing the SG-FRT distance in patient 2 resulted in faster thoracic thrombosis and increased total thrombus volume. Conclusion: The location of reentry tears can influence the progression of FL thrombosis following TEVAR. The more distal the reentry tear in the aorta the more likely it is that FL thrombosis will occur. Hence, the distal landing zone of the stent-graft should be chosen carefully to ensure a sufficient SG-FRT distance.

Accuracy of aortic dissection detection risk score alone or with D-dimer: A systematic review and meta-analysis

BACKGROUND

To evaluate the diagnostic accuracy and clinical utility of the acute aortic dissection detection risk score (ADD-RS) alone or with D-dimer as a screening test to exclude acute aortic syndrome.

METHODS

We conducted a systematic review and meta-analysis of studies examining the diagnostic accuracy of ADD-RS. We searched MEDLINE, Embase and Cochrane Controlled Register of Trials up to 12 December 2018.

RESULTS

We identified nine studies involving 26,598 patients for ADD-RS alone and 3421 patients with D-dimer. Overall, the methodological quality based on the Quality Assessment of Diagnostic Accuracy Studies 2 was moderate to high. Bivariate meta-analyses showed that the pooled sensitivities were 0.94 (95% confidence interval (CI) 0.90, 0.96) at the threshold of ADD-RS ≥1, 0.46 (95% CI, 0.34, 0.59) at ADD-RS ≥2, 1.00 (95% CI 0.99, 1.00) at ADD-RS ≥1 with D-dimer and 0.99 (95% CI 0.97, 1.00) at ADD-RS ≥2 with D-dimer. For the low prevalence population, failure rate and efficiency were 0.8% and 38.3% at ADD-RS ≥1, 0.03% and 14.5% at ADD-RS ≥1 with D-dimer, and 0.1% and 33.6% at ADD-RS ≥2 with D-dimer, respectively. For the high prevalence population, failure rate and efficiency were 3.8% and 33.3% at ADD-RS ≥1, 0.2% and 12.3% at ADD-RS ≥1 with D-dimer and 0.6% and 28.4% at ADD-RS ≥2 with D-dimer, respectively.

CONCLUSIONS

ADD-RS alone or with D-dimer was a useful screening test with high sensitivity to exclude acute aortic syndrome. However, the optimal threshold of ADD-RS alone or with D-dimer may depend on the clinical setting.

Decreased Abdominal Aortic Aneurysm Size Following EVAR in Patients With CT Evidence of Subclinical Thoracic Aortic Dissection

BACKGROUND

Aneurysm sac regression following endovascular repair (EVAR) of an abdominal aortic aneurysm (AAA) is an established indicator of surgical success. However, even with a completely excluded aneurysm, the degree of aortic sac regression may vary. This study evaluates the relationship between aneurysm sac regression after EVAR and the presence of morphological features in the thoracic aorta that can be associated with a subclinical aortic dissection, termed dissection morphology in this study.

METHODS

Patients who underwent EVAR to repair an infrarenal aortic aneurysm at Mount Sinai Hospital between 1996 and 2017 with a postoperative CT scan and a 3-year follow-up scan available for analysis were included in the study. Patients with a type I or type III endoleak were not included. The thoracic aorta was evaluated for dissection morphology on CT scan, which included the presence of aortic dissection, penetrating aortic ulcers, and intramural hematomas. AAA sac regression after EVAR was compared between patients with dissection morphology (n = 157) and patients without those characteristics (n = 141). An independent investigator performed the CT analysis and was blinded to the degree of sac regression.

RESULTS

Demographics and comorbid clinical conditions were compared between patients with and without dissection morphology. There were no significant differences in age, gender, smoking habits, or cardiovascular conditions. The median AAA diameter after EVAR, over the course of the study, in patients with dissection morphology decreased by 11.30 mm (-17.20, -3.60) compared to a median change of 0.30 mm (-8.60, 8.60) in patients without dissection morphology features (p < 0.001). Patients with dissection morphology also had fewer type II endoleaks in postoperative follow-up scans (22.9% vs. 53.9%, p < 0.001). Additionally, patients with dissection morphology had longer EVAR operative times (192.00 min [167.25, 230.00] vs.174.00 min [150.00, 215.00], p = 0.004). AAA-related mortality after 3 years was not significantly different between the 2 groups (p = 1.0).

CONCLUSIONS

The presence of imaging features consistent with dissection morphology in the thoracic aorta correlated with greater AAA sac regression and fewer type II endoleaks after EVAR. Assessing these imaging features in patients undergoing EVAR may be useful in understanding aneurysm behavior in terms of aneurysm growth, risk of rupture, and outcomes following endovascular surgery. Identifying differential rates of aneurysm sac regression may have implications regarding the role of subclinical dissections in the etiology of AAA development.

Timely identification of atypical acute aortic dissection in the emergency department:a study from a tertiary hospital

Background/aim

Acute aortic dissection (AAD) is a rare but fatal disease if left untreated. Symptoms are often similar to common conditions; therefore, the diagnostic strategy is important. We aimed to identify the atypical symptoms in a timely manner without putting patients at greater risk for undetected AAD.

Materials and methods

We conducted a retrospective observational study of 59 AAD patients with both atypical and typical symptoms from January 2012 to December 2016. Patients with atypical symptoms continuing more than 30 min underwent a D-dimer test and computed tomography (CT) or computed tomographic angiography (CTA).

Results

Of the 59 AAD patients, 22 were atypical. In the atypical group, the median delay time in our hospital was 3.1 h; average delay time after July 2015 was shorter than average delay time before June 2015 (16.59 ± 24.70 vs. 1.90 ± 0.57 h, P = 0.076).

Conclusions

For patients in the emergency department who are suspected of having AAD, incorporating atypical symptoms with high levels of D-dimer into a triage strategy could improve the efficiency of clinical decision making. Furthermore, essential education directed towards the recognition of the atypical symptoms of AAD for front-line physicians may aid in a timely diagnosis, as compared with the usual assessments in the emergency department.

Integration of Gene Expression Profile Data to Verify Hub Genes of Patients with Stanford A Aortic Dissection

Thoracic aortic dissection (TAD) is a catastrophic disease worldwide, but the pathogenic genes and pathways are largely unclear. This study aims at integrating two gene expression profile datasets and verifying hub genes and pathways involved in TAD as well as exploring potential molecular mechanisms. We will combine our mRNAs expression profile (6 TAD tissues versus 6 non-TAD tissues) and GSE52093 downloaded from the Gene Expression Omnibus (GEO) database. The two mRNAs expression profiles contained 13 TAD aortic tissues and 11 non-TAD tissues. The two expression profile datasets were integrated and we found out coexpression of differentially expressed genes (DEGs) using bioinformatics methods. The gene ontology and pathway enrichment of DEGs were performed by DAVID and Kyoto Encyclopedia of Genes and Genomes online analyses, respectively. The protein-protein interaction networks of the DEGs were constructed according to the data from the STRING database. Cytohubber calculating result shows the top 10 hub genes with CDC20, AURKA, RFC4, MCM4, TYMS, MCM2, DLGAP5, FANCI, BIRC5, and POLE2. Module analysis revealed that TAD was associated with significant pathways including cell cycle, vascular smooth muscle contraction, and adrenergic signaling in cardiomyocytes. The qRT-PCR result showed that the expression levels of all the hub genes were significantly increased in OA samples (p < 0.05), and these candidate genes could be used as potential diagnostic biomarkers and therapeutic targets of TAD.

Intermediate fenestrations reduce flow reversal in a silicone model of Stanford Type B aortic dissection

Pulsatile, three-dimensional hemodynamic forces influence thrombosis, and may dictate progression of aortic dissection. Intimal flap fenestration and blood pressure are clinically relevant variables in this pathology, yet their effects on dissection hemodynamics are poorly understood. The goal of this study was to characterize these effects on flow in dissection models to better guide interventions to prevent aneurysm formation and false lumen flow. Silicone models of aortic dissection with mobile intimal flap were fabricated based on patient images and installed in a flow loop with pulsatile flow. Flow fields were acquired via 4-dimensional flow MRI, allowing for quantification and visualization of relevant fluid mechanics. Pulsatile vortices and jet-like structures were observed at fenestrations immediately past the proximal entry tear. False lumen flow reversal was significantly reduced with the addition of fenestrations, from 19.2 ± 3.3% in two-tear dissections to 4.67 ± 1.5% and 4.87 ± 1.7% with each subsequent fenestration. In contrast, increasing pressure did not cause appreciable differences in flow rates, flow reversal, and vortex formation. Increasing the number of intermediate tears decreased flow reversal as compared to two-tear dissection, which may prevent false lumen thrombosis, promoting persistent false lumen flow. Vortices were noted to result from transluminal fluid motion at distal tear sites, which may lead to degeneration of the opposing wall. Increasing pressure did not affect measured flow patterns, but may contribute to stress concentrations in the aortic wall. The functional and anatomic assessment of disease with 4D MRI may aid in stratifying patient risk in this population.

Current state-of-play in spontaneous coronary artery dissection

For over 80 years, spontaneous coronary artery dissection (SCAD) has been recognised as a cause of myocardial infarction. SCAD is described as a non-iatrogenic, non-atherosclerotic coronary artery dissection, resulting in formation of a false lumen or intramural haematoma in the coronary artery wall that compresses the true lumen, often compromising myocardial blood flow. In early literature, the incidence of SCAD in acute coronary syndrome (ACS) was underestimated. Recent advances in awareness and widespread early angiographic investigation in ACS has led to important shifts in our understanding of the prevalence, predisposing causes, natural history, aetiology, clinical and angiographic features, management, and prognosis of SCAD. It is now well understood that SCAD predominantly affects women and is responsible for around 20% of ACS presentations in females below the age of 60. Despite this, SCAD is still often overlooked and misdiagnosed as atherosclerotic disease. Misdiagnosis is multifactorial; with contributing factors including a low clinical index of suspicion, particularly in young females, a lack of clinician familiarity with angiographic variants, and limitations of angiography. Although increasing evidence suggests that optimal management is distinct from atherosclerotic coronary artery disease, many questions remain unanswered regarding the pathogenesis and optimal treatment of SCAD, heralding prospective research to answer these questions. This review aims to give a current clinical perspective on SCAD and highlight the importance of familiarity and vigilance with this condition when diagnosing and treating ACS.

Thoracic Aortic Dissection Associated with Marijuana Use

BACKGROUND

Acute aortic dissection (AD) is a life-threatening condition most frequently seen in men with an average age >60 years. Risk factors include family history, hypertension and cigarette smoking. AD has been associated with methamephatamine and cocaine use but has not previously been associated with the use of marijuana.

CASE REPORT

We report a case of an aortic dissection in a 56-year-old male that occurred while smoking marijuana. The patient had a family history significant for both aortic aneurysm and dissection. He developed crushing chest pain, shortness of breath, and diaphoresis shortly after smoking marijuana from a glass pipe called a "bubbler". His ECG was unremarkable as was his chest x-ray and initial labs. CT scan revealed an Aortic dissection from the aortic root to the internal iliac artery. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The role of cannabis in cardiovascular disorders is complex and not completely understood. Acute chest pain associated with marijuana use typically raises concern for pneumothorax or pneumomediastinum. Marijuana has also been associated with hypertension and arrhythmias and has also been associated with an increased risk of myocardial infarction. However a link between marijuana and acute aortic dissection has not been previously reported. As more states legalize medical and recreational marijuana use this is a timely and important consideration for Emergency physicians evaluating chest pain. Our goal is to document the temporal relationship of cannabis use and acute aortic dissection in a recent ED patient.

Role of Macrophage Socs3 in the Pathogenesis of Aortic Dissection

BACKGROUND

Aortic dissection (AD) is a life-threatening medical emergency caused by the abrupt destruction of the intimomedial layer of the aortic walls. Given that previous studies have reported the involvement of proinflammatory cytokine interleukin-6 in AD pathogenesis, we investigated the role of signal transduction and activator of transcription 3 signaling, a downstream pathway of interleukin-6 in macrophages in pathogenesis of AD.

METHODS AND RESULTS

We characterized the pathological and molecular events triggered by aortic stress, which can lead to AD. Aortic stress on the suprarenal aorta because of infrarenal aorta stiffening and angiotensin II infusion for 1 week caused focal medial rupture at the branching point of the celiac trunk and superior mesenteric artery. This focal medial rupture healed in 6 weeks in wild-type (WT) mice, but progressed to AD in mice with macrophage-specific deletion of Socs3 gene (mSocs3-KO). mSocs3-KO mice showed premature activation of cell proliferation, an inflammatory response, and skewed differentiation of macrophages toward the tissue-destructive phenotype. Concomitantly, they showed aberrant phenotypic modulation of smooth muscle cells and transforming growth factor beta signaling, which are likely to participate in tissue repair. Human AD samples revealed signal transduction and activator of transcription 3 activation in adventitial macrophages adjacent to the site of tissue destruction.

CONCLUSIONS

These findings suggest that AD development is preceded by focal medial rupture, in which macrophage Socs3 maintains proper inflammatory response and differentiation of SMCs, thus promoting fibrotic healing to prevent tissue destruction and AD development. Understanding the sequence of the pathological and molecular events preceding AD development will help predict and prevent AD development and progression.

Characterization of serum miRNAs as molecular biomarkers for acute Stanford type A aortic dissection diagnosis

Early and convenient diagnosis is urgently needed for acute Stanford type A aortic dissection (AAAD) patients due to its high mortality within the first 48 hours. Circulating microRNAs (miRNAs) are promising biomarkers of cardiovascular diseases, however, little is known about circulating miRNAs involved in AAAD. Here, the blood serum was sampled from 104 AAAD+ patients and 103 age-matched donors. Initial screening was conducted using the TaqMan Low Density Array followed by RT-qPCR confirmation. According to the two-phase selection and validation process, we found that miR-25, miR-29a and miR-155 were significantly elevated, while miR-26b was markedly decreased in AAAD+ serum samples compared with AAAD- individuals. Most importantly, for individuals with hypertension, which is a major contributor to AAAD, the 4-miRNA panel also showed high accuracy in predicting those who are more likely to develop AAAD. In the blind trial set, the panel correctly classified 93.33% AAAD+ patients and 86.67% controls from the hypertension cohort. Finally, the serum miRNA-based biomarker for early AAAD detection was supported by a retrospective analysis. Taken together, we identify a distinct profile of 4-miRNA that can serve as a noninvasive biomarker for AAAD diagnosis, especially for those with hypertension.