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Thoracic aortic aneurysm is found in patients with ACTA2 pathogenic variants. ACTA2 missense variants are associated with impaired aortic smooth muscle cell (SMC) contraction. This study tested the hypothesis that the Acta2R149C/+ variant alters actin isoform expression and decreases integrin recruitment, thus, reducing aortic contractility. Stress relaxation measurements in thoracic aortic rings showed two functional regimes with a reduction of stress relaxation in the aorta from Acta2R149C/+ mice at low tension, but not at high tension values. Contractile responses to phenylephrine and potassium chloride were 50% lower in Acta2R149C/+ mice than in wild-type (WT) mice. Additionally, SMC were immunofluorescently labeled for specific proteins and imaged by confocal or total internal reflection fluorescence microscopy. The quantification of protein fluorescence of Acta2R149C/+ SMC showed a downregulation in smooth muscle α-actin (SMα-actin) and a compensatory upregulation of smooth muscle γ-actin (SMγ-actin) compared to WT cells. These results suggest that downregulation of SMα-actin leads to reduced SMC contractility, while upregulation of SMγ-actin may lead to increased SMC stiffness. Decreased α5β1 and α2β1 integrin recruitment at cell-matrix adhesions further reduce the ability of mutant cells to participate in cell-matrix crosstalk. Collectively, the results suggest that mutant Acta2R149C/+ aortic SMC have reduced contractility and interaction with the matrix, which are potential long-term contributing factors to thoracic aortic aneurysms.

Spontaneous coronary artery dissection (SCAD) is a potential precipitant of myocardial infarction and sudden death for which the etiology is poorly understood. Mendelian vascular and connective tissue disorders underlying thoracic aortic disease (TAD), have been reported in ~5% of individuals with SCAD. We therefore hypothesized that patients with TAD are at elevated risk for SCAD. We queried registries enrolling patients with TAD to define the incidence of SCAD. Of 7568 individuals enrolled, 11 (0.15%) were found to have SCAD. Of the sequenced cases (9/11), pathogenic variants were identified (N = 9), including COL3A1 (N = 3), FBN1 (N = 2), TGFBR2 (N = 2), TGFBR1 (N = 1), and PRKG1 (N = 1). Individuals with SCAD had an increased frequency of iliac artery dissection (25.0% vs. 5.1%, p = 0.047). The prevalence of SCAD among individuals with TAD is low. The identification of pathogenic variants in genes previously described in individuals with SCAD, particularly those underlying vascular Ehlers–Danlos, Marfan syndrome, and Loeys–Dietz syndrome, is consistent with prior reports from clinical SCAD series. Further research is needed to identify specific genetic influences on SCAD risk.

Thoracic aortic aneurysm and dissection are complex diagnoses that require management by multidisciplinary providers using a variety of medical therapies, surgical interventions, and lifestyle modifications. Pharmacological agents, such as β-blockers (atenolol) and angiotensin II type 1 receptor blockers (losartan), have been mainstay treatments for several years, and research from the past decade has continued to evaluate these and other medication classes to further improve patient morbidity and mortality. Combination β- and renin-aldosterone-angiotensin blockade, statins, metformin, antioxidants, and vitamins have been evaluated as therapeutics in both thoracic and abdominal aortic aneurysms, as well as the effects of various antibiotics (ie, fluoroquinolones and tetracyclines) and benefits of lifestyle modifications (eg, diet and exercise) and enhanced patient-centered care and treatment adherence. In addition, as our understanding of the genetic, biochemical, and pathophysiological mechanisms behind these diseases expands, so do potential targets for future therapeutic research (eg, interleukins, matrix metalloproteases, and mast cells). This review incorporates the major meta-analyses, systematic and generalized reviews, and clinical trials published from 2010 through 2021 that focus on these topics in thoracic aortic aneurysms (and abdominal aneurysms when thoracic literature is scarce). Several key ongoing clinical trials, case studies, and in vivo/in vitro studies are also mentioned. Furthermore, we discuss current gaps in the literature and the abundance of clinical evidence for some interventions in abdominal aneurysms with few thoracic correlates, thus indicating a need for investigation of these subjects in the latter.

Pregnancy-associated aortic dissection (AD) is a rare event, with an incidence of 0.0004% per pregnancy. The work of the Aortic Dissection Collaborative identified pregnancy-associated AD as a high-priority topic, despite its rarity. The Pregnancy Working Group, which included physicians and patient stakeholders, performed a systematic literature review of pregnancy-associated AD from 1960 to 2021 and identified 6,333 articles through PubMed, OVID MEDLINE, Cochrane, Embase, CINAHL and Web of Science. The inclusion criterion was AD in pregnant populations and exclusion criteria were case reports, conference abstracts, and languages other than English. Assessment of full-text articles for eligibility after removal of duplicates from all databases yielded 68 articles to be included in the final review. Topics included were timing of AD in pregnancy, type of AD, and management considerations of pregnancy-associated AD. The Pregnancy Working Group identified gaps in knowledge and future areas of research for pregnancy-associated AD, including clinical management, mental health outcomes post AD, reproductive and genetic counseling, and contraception after AD. Future collaborative projects could be a multicenter, international registry for all pregnancy-associated AD to refine the risk factors, best practice and management of AD in pregnancy. In addition, future mixed methodology studies may be useful to explore social, mental, and emotional factors related to pregnancy-associated AD and to determine support groups' effect on anxiety and depression related to these events in the pregnancy and postpartum period.

Telemedicine uses telephone-based or any form of digital communication for remote clinical services. It has been a field of interest for the last century, with broader implementation of telemedicine technologies during the last 25 years. The COVID-19 pandemic was an impetus for the adoption of these technologies globally across all health care services, including patient care, surgical practice, and workflow. As part of the patient engagement work in the Aortic Dissection Collaborative, this topic was identified as an important patient-centered research topic. Telemedicine has been adopted increasingly in vascular surgery; however, there is little evidence on appropriate use of these technologies pertaining to treating patients with aortic dissection or aortopathy in general. This landscape review summarizes the uses of telemedicine applications pre and post pandemic in medicine and vascular surgery, with a particular focus on uses in aortopathy. Using common resource databases, we identified articles related to the history of telemedicine, its current utilization, and application to vascular surgery and/or aortopathy. We briefly review the history of telemedicine and illustrate a range of applications in medicine before the pandemic, along with its rapid uptake globally during the COVID-19 pandemic. The enablers and barriers to using telemedicine are explored, although as a whole there is satisfaction with its integration among patients and providers. To address these, we offer recommendations to address future research as it pertains to telemedicine technologies in aortic dissection.

Although the topics of surgical techniques and medical therapies have been widely studied in aortic dissection (AD), studies examining the short- and long-term impact of this event on mental health are largely lacking. Many of the studies have used the 36-Item Short Form Survey at variable time points after the event. However, AD as medical trauma has a complex impact on a person's identity. Its implications for emotional, mental, social, existential, and self-concept could be explored more robustly. This topic was identified as a topic of interest by the AD Collaborative. The AD Collaborative Mental Health Working Group was formed and performed a landscape review to summarize current literature surrounding quality of life research in those who have experienced AD, identify gaps in knowledge, and to outline future research questions.

Aortic dissection confers high mortality and morbidity rates despite advances in treatment, impacts quality of life, and contributes immense burden to the healthcare system globally. Efforts to prevent aortic dissection through screening and management of modifiable risk factors and early detection of aneurysms should incorporate genomic information, as it is integral to stratifying risk. However, effective integration of genomic-guided risk assessment into clinical practice will require addressing implementation barriers that currently permeate our healthcare systems. The Aortic Dissection Collaborative was established to define aortic dissection research priorities through patient engagement. Using a collaborative patient-centered feedback model, our Genomic Medicine Working Group identified related research priorities that could be investigated by pragmatic interventional studies aimed at aortic dissection prevention, utilization of genomic information to improve patient outcomes, and access to genomic medicine services. Further research is also needed to identify the genomic, lifestyle, and environmental risk factors that contribute to aortic dissection so these data can be incorporated into future comparative effectiveness studies to prevent aortic dissection.

Understanding what matters most to patients can help guide research in a direction that is best situated to provide evidence that is responsive to their core concerns. This can better inform the treatment decision-making process for patients and their physicians. The Aortic Dissection (AD) Collaborative built a collaborative AD research infrastructure involving patients and other stakeholders to facilitate patient-centered outcomes research training, support, and networking among those affected by AD. Two surveys and semi-structured interviews were conducted between January and October 2020 to gather information from people with and at risk for AD and their family members to better understand their experiences and needs. Discussion of survey and interview results were then articulated as seven key topics for future research to meet the needs of the AD community. Working groups were assembled to address each of the key topics. The groups conducted landscape reviews that were focused on providing guidance for future research that directly addresses the needs identified by the AD community. Recommendations for future research generated by the working groups were compiled by the Aortic Dissection Collaborative. From these recommendations, the Aortic Dissection Collaborative advisors and stakeholders identified high-priority research questions. The research questions form the basis for a third survey, disseminated to the Virtual Research Network between November 2021 and February 2022. Final analysis of the survey will identify top ranked research questions and assess willingness to participate. These results will inform the development of future patient-centered outcomes research and comparative effectiveness research proposals.

Objective: Very few clinical predictors of descending thoracic aorta dissection have been determined. Although aneurysms can dissect in a size-dependent process, most descending dissections will occur without prior enlargement. We compared the proteomic profiles of normal, dissected, aneurysm, and both aneurysm and dissected descending thoracic aortas to identify novel biomarkers and further understand the molecular pathways that lead to tissue at risk of dissection. Methods: We performed proteomic profiling of descending thoracic aortas with four phenotypes: normal (n = 46), aneurysm (n = 22), dissected (n = 12), and combined aneurysm and dissection (n = 8). Pairwise differential protein expression analyses using a Bayesian approach were then performed to identify common proteins that were dysregulated between each diseased tissue type and control aorta and to uncover unique proteins between aneurysmal and dissected aortas. Network and Markov cluster algorithms of differentially expressed proteins were used to find enriched ontology processes. A convex analysis of mixtures was also performed to identify the molecular subtypes within the different tissue types. Results: The diseased aortas had 71 common differentially expressed proteins compared with the control, including higher amounts of the protein thrombospondin 1. We found 42 differentially expressed proteins between the aneurysm and dissected tissue, with an abundance of apolipoproteins in the former and higher quantities of extracellular matrix proteins in the latter. The convex analysis of mixtures showed enhancement of a molecular subtype enriched in contractile proteins within the control tissue compared with the diseased tissue, in addition to increased proportions of molecular subtypes enriched in inflammation and red blood cell expression in the aneurysmal compared with the dissected tissue. Conclusions: We found some overlapping differentially expressed proteins in aneurysmal and nonaneurysmal descending thoracic aortas at risk of dissection compared with normal aortas. However, we also found uniquely altered molecular pathways that might uncover mechanisms for dissection. Published version

Aim: The “2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease” provides recommendations to guide clinicians in the diagnosis, genetic evaluation and family screening, medical therapy, endovascular and surgical treatment, and long-term surveillance of patients with aortic disease across its multiple clinical presentation subsets (ie, asymptomatic, stable symptomatic, and acute aortic syndromes). Methods: A comprehensive literature search was conducted from January 2021 to April 2021, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, CINHL Complete, and other selected databases relevant to this guideline. Additional relevant studies, published through June 2022 during the guideline writing process, were also considered by the writing committee, where appropriate. Structure: Recommendations from previously published AHA/ACC guidelines on thoracic aortic disease, peripheral artery disease, and bicuspid aortic valve disease have been updated with new evidence to guide clinicians. In addition, new recommendations addressing comprehensive care for patients with aortic disease have been developed. There is added emphasis on the role of shared decision making, especially in the management of patients with aortic disease both before and during pregnancy. The is also an increased emphasis on the importance of institutional interventional volume and multidisciplinary aortic team expertise in the care of patients with aortic disease.

Thoracic aortic aneurysms (TAAs) that progress to acute thoracic aortic dissections (TADs) are life-threatening vascular events that have been associated with altered transforming growth factor (TGF) β signaling. In addition to TAA, multiple genetic vascular disorders, including hereditary hemorrhagic telangiectasia (HHT), involve altered TGFβ signaling and vascular malformations. Due to the importance of TGFβ, genomic variant databases have been curated for activin receptor-like kinase 1 (ALK1) and endoglin (ENG). This case report details seven variants in SMAD4 that are associated with either heritable or early-onset aortic dissections and compares them to pathogenic exon variants in gnomAD v2.1.1. The TAA and TAD variants were identified through whole exome sequencing of 346 families with unrelated heritable thoracic aortic disease (HTAD) and 355 individuals with early-onset (age ≤ 56 years old) thoracic aortic dissection (ESTAD). An allele frequency filter of less than 0.05% was applied in the Genome Aggregation Database (gnomAD exome v2.1.1) with a combined annotation-dependent depletion score (CADD) greater than 20. These seven variants also have a higher REVEL score (>0.2), indicating pathogenic potential. Further in vivo and in vitro analysis is needed to evaluate how these variants affect SMAD4 mRNA stability and protein activity in association with thoracic aortic disease.

Moyamoya disease (MMD) is characterized by narrowing of the distal internal carotid artery and the circle of Willis (CoW) and leads to recurring ischemic and hemorrhagic stroke. A retrospective review of data from 50 pediatric MMD patients revealed that, among the 24 who had a unilateral stroke and were surgically treated, 11 (45.8%) had a subsequent, contralateral stroke. There is no reliable way to predict these events. After a pilot study in Acta(−/−) mice that have features of MMD, we hypothesized that local hemodynamics are predictive of contralateral strokes and sought to develop a patient-specific analysis framework to noninvasively assess this stroke risk. A pediatric MMD patient with an occlusion in the right middle cerebral artery and a right-sided stroke, who was surgically treated and then had a contralateral stroke, was selected for analysis. By using an unsteady Navier-Stokes solver within an isogeometric analysis framework, blood flow was simulated in the CoW model reconstructed from the patient’s postoperative imaging data, and the results were compared with those from an age- and sex-matched control subject. A wall shear rate (WSR) > 60,000 s(−1) (about 12× higher than the coagulation threshold of 5000 s(−1) and 9× higher than control) was measured in the terminal left supraclinoid artery; its location coincided with that of the subsequent postsurgical left-sided stroke. A parametric study of disease progression revealed a strong correlation between the degree of vascular morphology altered by MMD and local hemodynamic environment. The results suggest that an occlusion in the CoW could lead to excessive contralateral WSRs, resulting in thromboembolic ischemic events, and that WSR could be a predictor of future stroke.

Pathogenic variant; Precision medicine; Thoracic aortic aneurysm Variante patógena; Medicina de precisión; Aneurisma de la aorta torácica Variant patògena; Medicina de precisió; Aneurisma de l'aorta toràcica Background Pathogenic variants in 11 genes predispose individuals to heritable thoracic aortic disease (HTAD), but limited data are available to stratify the risk for aortic events associated with these genes. Objectives This study sought to compare the risk of first aortic event, specifically thoracic aortic aneurysm surgery or an aortic dissection, among 7 HTAD genes and variant types within each gene. Methods A retrospective cohort of probands and relatives with rare variants in 7 genes for HTAD (n = 1,028) was assessed for the risk of first aortic events based on the gene altered, pathogenic variant type, sex, proband status, and location of recruitment. Results Significant differences in aortic event risk were identified among the smooth muscle contraction genes (ACTA2, MYLK, and PRKG1; P = 0.002) and among the genes for Loeys-Dietz syndrome, which encode proteins in the transforming growth factor (TGF)-β pathway (SMAD3, TGFB2, TGFBR1, and TGFBR2; P < 0.0001). Cumulative incidence of type A aortic dissection was higher than elective aneurysm surgery in patients with variants in ACTA2, MYLK, PRKG1, and SMAD3; in contrast, patients with TGFBR2 variants had lower cumulative incidence of type A aortic dissection than elective aneurysm surgery. Cumulative incidence of type B aortic dissection was higher for ACTA2, PRKG1, and TGFBR2 than other genes. After adjusting for proband status, sex, and recruitment location, specific variants in ACTA2 and TGFBR2 were associated with substantially higher risk of aortic event with childhood onset. Conclusions Gene- and variant-specific data on aortic events in individuals with HTAD support personalized aortic surveillance and clinical management. These studies were funded by the National Institutes of Health (NIH) (NIH R01HL109942 to Dr Milewicz DMM and K23HL127266 to Dr Morris), Genetic Aortic Disorders Association Canada, Temerty Family Foundation, and the John Ritter Foundation. Dr LeMaire serves as a consultant for Terumo Aortic and Cerus; and serves as a principal investigator for clinical studies sponsored by Terumo Aortic and CytoSorbents. Dr Morris is on the scientific advisory board for vascular Ehlers Danlos syndrome clinical trial for Aytu Biopharma. Dr Regalado is an employee and shareholder of Invitae. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Background: Vascular smooth muscle cells (SMCs) undergo complex phenotypic modulation with atherosclerotic plaque formation in hyperlipidemic mice, which is characterized by de-differentiation and heterogeneous increases in the expression of macrophage, fibroblast, osteogenic, and stem cell markers. An increase of cellular cholesterol in SMCs triggers similar phenotypic changes in vitro with exposure to free cholesterol due to cholesterol entering the endoplasmic reticulum, triggering endoplasmic reticulum stress and activating Perk (protein kinase RNA-like endoplasmic reticulum kinase) signaling. Methods: We generated an SMC-specific Perk knockout mouse model, induced hyperlipidemia in the mice by AAV- PCSK9 DY injection, and subjected them to a high-fat diet. We then assessed atherosclerotic plaque formation and performed single-cell transcriptomic studies using aortic tissue from these mice. Results: SMC-specific deletion of Perk reduces atherosclerotic plaque formation in male hyperlipidemic mice by 80%. Single-cell transcriptomic data identify 2 clusters of modulated SMCs in hyperlipidemic mice, one of which is absent when Perk is deleted in SMCs. The 2 modulated SMC clusters have significant overlap of transcriptional changes, but the Perk-dependent cluster uniquely shows a global decrease in the number of transcripts. SMC-specific Perk deletion also prevents migration of both contractile and modulated SMCs from the medial layer of the aorta. Conclusions: Our results indicate that hypercholesterolemia drives both Perk-dependent and Perk-independent SMC modulation and that deficiency of Perk significantly blocks atherosclerotic plaque formation.

The objective of this study was to compare midterm outcomes of aortic valve-replacing root replacement (AVR) and aortic valve-sparing root replacement (AVS) operations in patients with Marfan syndrome.Patients who met strict Ghent diagnostic criteria for Marfan syndrome and who underwent either AVR or AVS between March 1, 2005 and December 31, 2010 were enrolled in a 3-year follow-up prospective, multicenter, international registry study; the study was subsequently amended to include 20-year follow-up. Enrollees were followed clinically and echocardiographically.Of the 316 patients enrolled, 77 underwent AVR and 239 underwent AVS; 214 gave reconsent for 20-year follow-up. The median clinical follow-up time for surviving patients was 64 months (interquartile range, 42-66 months). Survival rates for the AVR and AVS groups were similar at 88.2% ± 4.4% and 95.0% ± 1.5%, respectively (P = .1). Propensity score-adjusted competing risk modeling showed associations between AVS and higher cumulative incidences of major adverse valve-related events, valve-related morbidity, combined structural valve deterioration and nonstructural valve dysfunction, and aortic regurgitation ≥2+ (all P .01). No differences were found for reintervention (P = .7), bleeding (P = .2), embolism (P = .3), or valve-related mortality (P = .8).Five years postoperatively, major adverse valve-related events and valve-related morbidity were more frequent after AVS than after AVR procedures, primarily because of more frequent aortic valve dysfunction. No between-group differences were found in rates of survival, valve-related mortality, reintervention on the aortic valve, or bleeding. We plan to follow this homogenous cohort for 20 years after aortic root replacement.

Purpose: Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening disease with often unrecognized inherited forms. We sought to identify novel pathogenic variants associated with autosomal dominant inheritance of TAAD. Methods: We analyzed exome sequencing data from 35 French TAAD families and performed next-generation sequencing capture panel of genes in 1114 unrelated TAAD patients. Functional effects of pathogenic variants identified were validated in cell, tissue, and mouse models. Results: We identified five functional variants in THSD4 of which two heterozygous variants lead to a premature termination codon. THSD4 encodes ADAMTSL6 (member of the ADAMTS/L superfamily), a microfibril-associated protein that promotes fibrillin-1 matrix assembly. The THSD4 variants studied lead to haploinsufficiency or impaired assembly of fibrillin-1 microfibrils. Thsd4+/− mice showed progressive dilation of the thoracic aorta. Histologic examination of aortic samples from a patient carrying a THSD4 variant and from Thsd4+/− mice, revealed typical medial degeneration and diffuse disruption of extracellular matrix. Conclusion: These findings highlight the role of ADAMTSL6 in aortic physiology and TAAD pathogenesis. They will improve TAAD management and help develop new targeted therapies.

Supplemental Digital Content is available in the text., Objective: Vascular smooth muscle cells (SMCs) dedifferentiate and initiate expression of macrophage markers with cholesterol exposure. This phenotypic switching is dependent on the transcription factor Klf4 (Krüppel-like factor 4). We investigated the molecular pathway by which cholesterol induces SMC phenotypic switching. Approach and Results: With exposure to free cholesterol, SMCs decrease expression of contractile markers, activate Klf4, and upregulate a subset of macrophage and fibroblast markers characteristic of modulated SMCs that appear with atherosclerotic plaque formation. These phenotypic changes are associated with activation of all 3 pathways of the endoplasmic reticulum unfolded protein response (UPR), Perk (protein kinase RNA-like endoplasmic reticulum kinase), Ire (inositol-requiring enzyme) 1α, and Atf (activating transcription factor) 6. Blocking the movement of cholesterol from the plasma membrane to the endoplasmic reticulum prevents free cholesterol–induced UPR, Klf4 activation, and upregulation of the majority of macrophage and fibroblast markers. Cholesterol-induced phenotypic switching is also prevented by global UPR inhibition or specific inhibition of Perk signaling. Exposure to chemical UPR inducers, tunicamycin and thapsigargin, is sufficient to induce these same phenotypic transitions. Finally, analysis of published single-cell RNA sequencing data during atherosclerotic plaque formation in hyperlipidemic mice provides preliminary in vivo evidence of a role of UPR activation in modulated SMCs. Conclusions: Our data demonstrate that UPR is necessary and sufficient to drive phenotypic switching of SMCs to cells that resemble modulated SMCs found in atherosclerotic plaques. Preventing a UPR in hyperlipidemic mice diminishes atherosclerotic burden, and our data suggest that preventing SMC transition to dedifferentiated cells expressing macrophage and fibroblast markers contributes to this decreased plaque burden.

Missense pathogenic variants in ACTA2, encoding α-smooth muscle actin (SMA), predispose to thoracic aortic aneurysms. A subset of these ACTA2 pathogenic variants also predispose to childhood onset cerebrovascular disease characterized by occlusion of the distal internal carotid arteries and small vessel disease. In our studies to identify how specific ACTA2 pathogenic variants predispose to cerebrovascular disease, we confirmed that SMA is localized to the nucleus in wildtype (WT) smooth muscle cells (SMCs), is enriched in the nucleus over β-actin with differentiation of SMCs, associates with the INO80 chromatin remodeling complex, and selectively binds to the promoters of SMC contractile genes. Pluripotent stem cell-derived SMCs from patients with ACTA2 -associated cerebrovascular disease ( ACTA2 R179C) as well as SMCs explanted from a knockin mouse model ( Acta2 SMC-R179C/+ ) confirm that R179 variants disrupt SMA nuclear localization. Both mouse and human cells harboring the R179C pathogenic variant proliferate and migrate more than WT SMCs, are less differentiated than WT SMCs, and have increased expression of pluripotency-associated genes. Although the variant is heterozygous, these cells show a dominant negative impact on nuclear SMA function through dramatically reduced levels of SMA in the nucleus, in the INO80 chromatin remodeling complex, and on the promoters of SMC-specific genes. Finally, single cell RNA sequencing analysis of aortic tissue from an ACTA2 R179H patient confirms dedifferentiation of SMCs as a key phenotype associated with this mutation. Taken together, we have identified a novel role for α-SMA in driving differentiation of SMCs, and our data supports that defects in this nuclear role drive cellular phenotypes consistent with the cerebrovascular disease seen in patients with ACTA2 R179 pathogenic variants.