Diagnostic approach and management of genetic aortopathies

Marfan and Loeys-Dietz aortic phenotype: A potential tool for diagnosis and management

Objective

In heritable aortic diseases, different vascular involvement may occur with potential variable implications in aortic dilation/dissection risk. This study aimed to analyze the aortic anatomy of individuals with Marfan syndrome and Loeys-Dietz syndrome to identify possible morphological differences.

Methods

Computed tomography and magnetic resonance imaging of the thoracoabdominal aorta from the proximal supra-aortic vessels to the femoral bifurcation level of 114 patients with Marfan and Loeys-Dietz syndromes and 20 matched control subjects were examined. Aortic diameters, areas, length, and tortuosity were measured in different aortic segments using specific vessel analysis software.

Results

Patients with Marfan syndrome showed a higher prevalence of ascending aorta and aortic root dilation (P = .011), larger and longer aortic roots (P = .013) with pear-shaped phenotype, larger isthmus/descending aorta diameter ratio (P = .015), and larger suprarenal aorta and iliac arteries. Patients with Loeys-Dietz syndrome showed longer indexed segments and a significantly longer arch (P = .006) with type 2/3 arch prevalence (P = .097). Measurement ratios analysis provided cut-off values (aortic root to ascending aorta length/aortic root diameter, aortic root/sinotubular junction, aortic root/ascending aorta diameter) differentiating patients with Marfan syndrome from patients with Loeys-Dietz syndrome, even in the early stage of the disease.

Conclusions

Both syndromes show peculiar anatomic patterns at different aortic levels irrespective of aortic dilation and disease severity. These features may represent the expression of different genetic mutations on aortic development, with a potential impact on prognosis and possibly contributing to better management of the diseases. The systematic adoption of whole body imaging with magnetic resonance or computed tomography should always be considered, because they allow a complete vascular assessment with practical indicators of differential diagnosis.

Heritable thoracic aortic disease: a literature review on genetic aortopathies and current surgical management

Heritable thoracic aortic disease puts patients at risk for aortic aneurysms, rupture, and dissections. The diagnosis and management of this heterogenous patient population continues to evolve. Last year, the American Heart Association/American College of Cardiology Joint Committee published diagnosis and management guidelines for aortic disease, which included those with genetic aortopathies. Additionally, evolving research studying the implications of underlying genetic aberrations with new genetic testing continues to become available. In this review, we evaluate the current literature surrounding the diagnosis and management of heritable thoracic aortic disease, as well as novel therapeutic approaches and future directions of research.

Hereditary Thoracic Aortic Diseases

Advances in both imaging techniques and genetics have led to the recognition of a wide variety of aortic anomalies that can be grouped under the term 'hereditary thoracic aortic diseases'. The present review aims to summarize this very heterogeneous population's clinical, genetic, and imaging characteristics and to discuss the implications of the diagnosis for clinical counselling (on sports activity or pregnancy), medical therapies and surgical management.

Thoracic Aortic Aneurysmal Disease: Comprehensive Recommendations for the Primary Care Physician

Thoracic aortic aneurysm (TAA) is a commonly encountered disease that is defined as aortic dilation with an increase in diameter of at least 50% greater than the expected age- and sex-adjusted size. Thoracic aortic aneurysms are described by their size, location, morphology, and cause. Primary care clinicians and other noncardiologists are often the first point of contact for patients with TAA. This review is intended to provide them with basic information on the differential diagnosis, diagnostic evaluation, and medical and surgical management of TAAs. Management decisions depend on having as precise a diagnosis as possible. Fortunately, this can often be achieved with a stepwise diagnostic approach that incorporates imaging and targeted genetic testing. Our review includes recommendations. In this review, we discuss these issues at a basic level and include recommendations for patients considering pregnancy.

Genetic Basis, New Diagnostic Approaches, and Updated Therapeutic Strategies of the Syndromic Aortic Diseases: Marfan, Loeys-Dietz, and Vascular Ehlers-Danlos Syndrome

Syndromic aortic diseases (SADs) encompass various pathological manifestations affecting the aorta caused by known genetic factors, such as aneurysms, dissections, and ruptures. However, the genetic mutation underlying aortic pathology also gives rise to clinical manifestations affecting other vessels and systems. As a consequence, the main syndromes currently identified as Marfan, Loeys-Dietz, and vascular Ehlers-Danlos are characterized by a complex clinical picture. In this contribution, we provide an overview of the genetic mutations currently identified in order to have a better understanding of the pathogenic mechanisms. Moreover, an update is presented on the basis of the most recent diagnostic criteria, which enable an early diagnosis. Finally, therapeutic strategies are proposed with the goal of improving the rates of patient survival and the quality of life of those affected by these SADs.

Aortopathies: From Etiology to the Role of Arterial Stiffness

The aorta and aortic wall have a complex biological system of structural, biochemical, biomolecular, and hemodynamic elements. Arterial stiffness could be considered a manifestation of wall structural and functional variations, and it has been revealed to have a strong connection with aortopathies and be a predictor of cardiovascular risk, especially in patients affected by hypertension, diabetes mellitus, and nephropathy. Stiffness affects the function of different organs, especially the brain, kidneys, and heart, promoting remodeling of small arteries and endothelial dysfunction. This parameter could be easily evaluated using different methods, but pulse-wave velocity (PWV), the speed of transmission of arterial pressure waves, is considered the gold standard for a good and precise assessment. An increased PWV value indicates an elevated level of aortic stiffness because of the decline in elastin synthesis and activation of proteolysis and the increase in fibrosis that contributes to parietal rigidity. Higher values of PWV could also be found in some genetic diseases, such as Marfan syndrome (MFS) or Loeys-Dietz syndrome (LDS). Aortic stiffness has emerged as a major new cardiovascular disease (CVD) risk factor, and its evaluation using PWV could be very useful to identify patients with a high cardiovascular risk, giving some important prognostic information but also being used to value the benefits of therapeutic strategies.

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

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

Computed tomography for aortic assessment in children

Because the aorta is the major vessel of the body, basic knowledge of aortic pathology is essential to the pediatric imager. This review divides aortic pathology into anatomical (e.g., congenital abnormalities) and acquired (e.g., vasculitis, trauma) entities, providing a brief description of pathology, technical considerations in CT acquisition and processing, and some pearls and pitfalls of interpretation. The objective of this paper is to familiarize general pediatric imagers with imaging features of common as well as high-impact aortic pathology on CT and prepare them for acquisition and reporting.

Differential Diagnosis of Multiple Systemic Aneurysms

Atherosclerosis and systemic hypertension are the most common pathogeneses of solitary acquired arterial aneurysms. The rare occurrence of multiple synchronous or metachronous arterial aneurysms requires considering alternative underlying causes. We present the unusual case of a male patient who sequentially developed multiple co-existing arterial aneurysms between the ages of 51 and 59. The sites of involvement included high-pressure systemic arteries and low-pressure pulmonary arteries. We discuss the broad differential diagnosis that includes heritable and non-inheritable etiologies. A keen clinical awareness of this broader array of arterial aneurysms is essential for accurate early diagnosis and proper management.

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

Objectives

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

Methods

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

Results

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

Conclusions

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

The Relevance of Skin Biopsies in General Internal Medicine: Facts and Myths

INTRODUCTION

Non-dermatology medical specialties may refer patients for skin biopsies, searching for a particular diagnosis. However, the diagnostic impact of the skin biopsy is not clearly established. This article aims to assess the indications for, and evaluate the clinical relevance of, skin biopsies in non-dermatology medical specialties.

METHODS

A questionnaire was sent to 23 non-dermatology specialty departments in a university medical center, requesting a list of indications for skin biopsies, as well as to 10 staff dermatologists to collect the indications of skin biopsies requested by non-dermatology specialties. Once the indications were collected, a literature search was performed to evaluate their clinical value and relevance.

RESULTS

Eleven non-dermatology specialties provided a list of skin biopsy indications, to which staff dermatologists added seven more indications. A literature search revealed evidence-based medicine data for six diseases, that is, amyloidosis, peripheral autonomic neuropathy, Sneddon's syndrome, intravascular lymphoma, sarcoidosis, and chronic graft-versus-host disease. Results were questionable concerning infectious endocarditis, acute graft-versus-host-disease, and the lupus band test. Skin biopsy were not evidenced as useful for the diagnosis of calciphylaxis, systemic scleroderma, Behçet's disease, or hypermobile Ehlers-Danlos syndrome. For the diagnosis of Alport's syndrome, pseudoxanthoma elasticum, and vascular Ehlers-Danlos syndrome, skin biopsy is currently outperformed by genetic analyses. For diagnoses such as Henoch-Schönlein purpura and Sjögren's syndrome, skin biopsy represents an additional item among other diagnostic criteria.

CONCLUSION

The usefulness of skin biopsy as requested by non-dermatology specialties is only evidenced for amyloidosis, peripheral autonomic neuropathy, Sneddon's syndrome, intravascular lymphoma, sarcoidosis, chronic graft-versus-host-disease, Henoch-Schönlein purpura, and Sjögren's syndrome.

Complex and Successful Management of a Symptomatic Isolated Abdominal Aortic Aneurysm in a Pregnant Woman with Marfan Syndrome

Aortopathies associated to Marfan syndrome (MFS) are important causes of maternal death during pregnancy. We present a 27-year-old and 24-week pregnant MFS woman who arrived to the emergency department with increasing abdominal pain; an obstetric ultrasound showed an Abdominal Aortic Aneurysm (AAA), a multislice computed tomography angiography (CTA) confirmed and demonstrated a 7.3 centimeter (cm) infrarenal AAA without evidence of dissection. A multidisciplinary committee determined that an open repair would lead to a significantly high maternal-fetal morbidity and mortality. Although endovascular repair (EVAR) in MFS patients remains controversial, an urgent bridge therapy was considered to be the best option. She was transferred to the angiography suite for EVAR to prevent AAA rupture and ensure a satisfactory pregnancy. The patient and fetus presented no complications during the procedure and were discharged 3 days later. She continued her pregnancy without eventualities and an elective C-section was performed on week 36. A CTA imaging at 12 months revealed type 1A and 3 endoleaks, we decided to perform endograft explant and a definitive open repair, there were no complications during the procedure, the patient is currently asymptomatic. Our case illustrates a complex decision and management that successfully avoid morbidity and mortality of a MFS mother and her product; additionally, this experience reinforces the need for lifelong and close surveillance in these patients.

Rare Causes of Arterial Hypertension and Thoracic Aortic Aneurysms-A Case-Based Review

Thoracic aortic aneurysms may result in dissection with fatal consequences if undetected. A young male patient with no relevant familial history, after having been investigated for hypertension, was diagnosed with an ascending aortic aneurysm involving the aortic root and the proximal tubular segment, associated with a septal atrial defect. The patient underwent a Bentall surgery protocol without complications. Clinical examination revealed dorso-lumbar scoliosis and no other signs of underlying connective tissue disease. Microscopic examination revealed strikingly severe medial degeneration of the aorta, with areas of deep disorganization of the medial musculo-elastic structural units and mucoid material deposition. Genetic testing found a variant of unknown significance the PRKG1 gene encoding the protein kinase cGMP-dependent 1, which is important in blood pressure regulation. There may be genetic links between high blood pressure and thoracic aortic aneurysm determinants. Hypertension was found in FBN1 gene mutations encoding fibrillin and in PRKG1 mutations. Possible mechanisms involving the renin-angiotensin system, the role of oxidative stress, osteopontin, epigenetic modifications and other genes are reviewed. Close follow-up and strict hypertension control are required to reduce the risk of dissection. Hypertension, scoliosis and other extra-aortic signs suggesting a connective tissue disease are possible clues for diagnosis.

Thoracic and abdominal aortic aneurysms: exploring their contrast and genetic associations

Until recently thoracic aortic aneurysm (TAA) and abdominal aortic aneurysm (AAA) were correlated with atherosclerosis but following a range of cohort studies, a linkage proved unlikely. Instead, data from the Genome wide association study detected two common significantly correlated lncRNA loci: miRNA and the antisense non-coding RNA in the INK4 locus (ANRIL). lncRNAs are sometimes utilized by the body as transcription regulators and signaling molecules. This is crucial in cell transformation and embryology, including that of the mammalian heart. ANRIL, a 19 exon RNA sequence found in the chromosome 9p21 region, will be one of the main focuses of this paper. TAA and AAA have many differences due to their vessel walls but similarities in their gross anatomic structure prove a genetic correlated disease likely. ANRIL has a convincing potential to be used as an additive therapeutic tool in TAA and AAA. This is because Chr9p21 is independent of typical risk factors. However, it remains that further research and clinical studies are required before clinical translation. It is best to consider TAA and AAA separately as the underlying pathophysiology has some distinct differences. They are both commonly diagnosed late, and the hope is that genetic mutations (ANRIL) can act as a biomarker for a faster diagnosis, management and possible treatment alternative.

Cardiogenetics: genetic testing in the diagnosis and management of patients with aortic disease

Thoracic aortic aneurysm and aortic dissection have a potent genetic underpinning with 20% of individuals having an affected relative. Heritable thoracic aortic diseases (HTAD) may be classified as syndromic (including Marfan syndrome, Loeys-Dietz syndrome, vascular Ehlers-Danlos syndrome and others) or non-syndromic (without recognisable phenotypes) and relate to pathogenic variants in multiple genes affecting extracellular matrix proteins, transforming growth factor-beta (TGF-β) signalling and smooth muscle contractile function. Clinical and imaging characteristics may heighten likelihood of an underlying HTAD. HTAD should be investigated in individuals with thoracic aortic aneurysm or aortic dissection, especially when occurring in younger individuals, in those with phenotypic features and in those with a family history of aneurysm disease. Screening family members for aneurysm disease is important. Consultation with a medical geneticist and genetic testing of individuals at increased risk for HTAD is recommended. Medical management and prophylactic aortic surgical thresholds are informed by an accurate clinical and molecular diagnosis.

Efficient detection of differentially methylated regions in the genome of patients with thoracic aortic dissection and association with MMP2 hypermethylation

DNA methylation is known to regulate the expression of numerous genes but its role in the pathogenesis of thoracic aortic dissection (TAD) has remained largely elusive. In the present study, the DNA methylome of patients with TAD was analyzed using a methylation microarray and bisulfite pyrosequencing was used to determine whether the hypermethylation of matrix metalloproteinase 2 (MMP2) specifically is associated with TAD. Chip-based whole-DNA methylome analysis was performed on 4 male patients with TAD and 4 male healthy controls using an Illumina HumanMethylation EPIC 850K BeadChip. The resulting data were analyzed by clustering and principal component analysis, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed on the differentially methylated genes to interrogate their biological functions. Compared to the healthy controls, 3,362 loci were differentially methylated in the patients with TAD with a statistical significance of P<0.05, while 1,223 loci had a significance of P<0.01. Among these loci, 2,019 were hypermethylated and 1,343 were hypomethylated. From GO analysis within the biological process category, the MMP2, MMP14 and WNT2B genes were identified. enrichment was observed for loci involved in cellular component organization, enzyme-linked receptor protein signaling pathways (potentially having a key role in the development of cardiopulmonary function disorders) and vascular reconstruction. Bisulfite pyrosequencing of plasma samples indicated significantly increased methylation (P<0.01) of the CpG site at position 2 in the promoter of MMP2 in the TAD group relative to the healthy controls, and the mean methylation level of four CpG sites on the MMP2 gene in the TAD group was slightly higher than that in the control group, but not significantly. Hypermethylation of the MMP2 promoter may be a promising novel diagnostic and prognostic biomarker for TAD. Future studies on the epigenetics of biomarkers linked to vascular reconstruction and immune function may provide further insight into the pathogenesis and progression of TAD.