Prognostic significance of the pattern of aortic root dilation in the Marfan syndrome

Estimation of z-scores of cardiac structures in healthy children in Southeast Nigeria

BACKGROUND

The z-scoring system shows the mean deviation of cardiac dimensions from age-specific population. The use of the European-based z-score studies has resulted in misdiagnosis and late treatment of Nigerian children with heart diseases leading to increased mortality and morbidity.

OBJECTIVES

This study aimed to determine the z‑scores for various cardiac structures and functions among healthy children in Southeast Nigeria.

MATERIALS AND METHODS

This is a cross-sectional observational study where z-scores of the cardiac structure and function of three hundred healthy children were estimated using echocardiography and compared with the standard Detroit values.

RESULT

There was a significant positive correlation between age and cardiac valve diameter. The aortic valve strongly correlated positively with age with the Pearson correlation coefficient (ρ) of 0.8 and probability value (P-value) of 0.00. None of the ventricular function variables deviated beyond the +2 or -2 z-score. There was a positive correlation between the z-scores of ventricular function parameters and participants' age, although the strength of the correlation varied. Comparing these values with that of Detroit values, there was a significant difference in the deviation of the mean of the mitral valve and left pulmonary artery diameters from the Detroit values between the males and the females. While the mean z-score mitral valve was 0.8 in males, it was 0.6 in females (P = 0.02).

CONCLUSION

Z-scores of cardiac structures and function are derived from children in this locale. These values were similar to that of Detroit values except for the mitral valve and left pulmonary artery.

Echogenomics: Echocardiography in Heritable Aortopathies

PURPOSE OF REVIEW

The aim of this article is to review the current echocardiographic considerations in the diagnosis and monitoring of patients with inherited aortopathies.

RECENT FINDINGS

Aortic dilation is a key feature in heritable aortopathies, and dissection is a leading cause of morbidity and mortality. New genetic and histopathologic findings are helpful in better understanding these conditions. Non-invasive imaging modalities, including echocardiogram, computerized tomography, and magnetic resonance imaging, are essential in monitoring these patients, as well as providing new prognostic factors of arterial stiffness that may help with risk stratification in the future. Diagnosis of heritable aortopathies should be considered with identification of aortic root dilation, particularly in children and young adults, or when there is a family history of aortic disease. Recent adult consensus guidelines highlight the importance of underlying genotype and phenotypic features when considering prophylactic surgical intervention. There are currently no consensus pediatric guidelines.

Growth of the Neo-Aortic Root and Prognosis of Transposition of the Great Arteries

BACKGROUND

Neo-aortic root dilatation can lead to significant late morbidity after the arterial switch operation (ASO) for dextro-transposition of the great arteries (d-TGA).

OBJECTIVES

We sought to examine the growth of the neo-aortic root in d-TGA.

METHODS

A single-center, retrospective cohort study of patients who underwent the ASO between July 1, 1981 and September 30, 2022 was performed. Morphology was categorized as dextro-transposition of the great arteries with intact ventricular septum (d-TGA-IVS), dextro-transposition of the great arteries with ventricular septal defect (d-TGA-VSD), and double-outlet right ventricle-transposition of the great arteries type (DORV-TGA). Echocardiographically determined diameters and derived z scores were measured at the annulus, sinus of Valsalva, and sinotubular junction immediately before the ASO and throughout follow-up. Trends in root dimensions over time were assessed using linear mixed-effects models. The association between intrinsic morphology and the composite of moderate-severe aortic regurgitation (AR) and neo-aortic valve or root intervention was evaluated with univariable and multivariable Cox proportional hazards models.

RESULTS

Of 1,359 patients who underwent the ASO, 593 (44%), 666 (49%), and 100 (7%) patients had d-TGA-IVS, d-TGA-VSD, and DORV-TGA, respectively. Each patient underwent a median of 5 echocardiograms (Q1-Q3: 3-10 echocardiograms) over a median follow-up of 8.6 years (range: 0.1-39.3 years). At 30 years, patients with DORV-TGA demonstrated greater annular (P < 0.001), sinus of Valsalva (P = 0.039), and sinotubular junction (P = 0.041) dilatation relative to patients with d-TGA-IVS. On multivariable analysis, intrinsic anatomy, older age at ASO, at least mild AR at baseline, and high-risk root dilatation were associated with moderate-severe AR and neo-aortic valve or root intervention at late follow-up (all P < 0.05).

CONCLUSIONS

Longitudinal surveillance of the neo-aortic root is warranted long after the ASO.

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.

Longitudinal follow-up by MR angiography reveals progressive dilatation of the distal aorta after aortic root replacement in Marfan syndrome

OBJECTIVES

To define and compare growth rates of the distal aorta in Marfan patients with and without aortic root replacement using serial MR angiography (MRA).

METHODS

We retrospectively included 136 Marfan patients with a total of 645 MRAs who underwent a median of five MRAs (range: 2-13) at 1.5 T and 3 T in annual intervals. Of these, 41 patients (34.8 ± 12 years) had undergone aortic root replacement. The remaining 95 patients (29.0 ± 17 years) still had a native aorta and served as the control group. Thoracic aortic diameters were independently measured at eleven predefined levels. Estimated growth rates were calculated using a mixed effects model adjusted for sex, age, BMI, and medication.

RESULTS

Marfan patients with aortic root replacement revealed the highest mean estimated growth rate in the proximal descending aorta (0.77 mm/year, CI: 0.31-1.21). Mean growth rates at all levels of the distal thoracic aorta were significantly higher in patients with aortic root replacement (0.28-0.77 mm/year) when compared to patients without aortic root replacement (0.03-0.07 mm/year) (all p < 0.001). Antihypertensive medication, gender, and BMI had no significant impact on the distal aortic growth rates.

CONCLUSION

Distal thoracic aortic diameters increase at a significantly higher rate in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. Further studies are warranted to investigate if the increased growth rate of the distal thoracic aorta after aortic root replacement is caused by altered hemodynamics due to the rigid aortic root graft or due to the general genetic disposition of post-operative Marfan patients.

CLINICAL RELEVANCE STATEMENT

High growth rates of the distal aorta after aortic root replacement underline the need for careful life-long aortic imaging of Marfan patients after aortic root replacement.

KEY POINTS

• Aortic growth rates in Marfan patients with aortic root replacement are highest in the mid-aortic arch, the proximal- and mid-descending aorta. • Growth rates of the distal thoracic aorta are significantly higher in Marfan patients with aortic root replacement compared to Marfan patients without aortic root replacement. • Antihypertensive medication, gender, and BMI have no significant impact on distal aortic growth rates in Marfan patients.

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.

Growth of the aortic root in children and young adults with Marfan syndrome

OBJECTIVES

The primary aim was to gain insight into the growth of the aortic root in children and young adults with Marfan syndrome (MFS). Furthermore, we aimed to identify a clinical profile of patients with MFS who require an aortic root replacement at a young age with specific interest in age, sex, height and fibrillin-1 (FBN1) genotype.

METHODS

Aortic root dimensions of 97 patients with MFS between 0 year and 20 years and 30 controls were serially assessed with echocardiography. Trends were analysed using a linear mixed-effect model. Additionally, including only patients with MFS, we allowed trends to differ by sex, aortic root replacement and type of FBN1 mutation.

RESULTS

Average aortic root dilatation in patients with MFS became more pronounced after the age of 8 years. In the MFS cohort, male patients had a significantly greater aortic root diameter than female patients, which was in close relationship with patient height. There was no difference in aortic root growth between children with dominant negative (DN) or haploinsufficient FBN1 mutations. However, DN-FBN1 variants resulting in loss of cysteine content were associated with a more severe phenotype. Eleven children needed an aortic root replacement. Compared with patients with MFS without aortic root surgery, these children had a significantly larger aortic root diameter from an early age.

CONCLUSIONS

This study provides clinically useful longitudinal growth charts on aortic root growth in children and young adults with MFS. Children requiring prophylactic aortic root replacement during childhood can be identified at a young age. Our growth charts can help clinicians in decision making with regard to follow-up and prophylactic therapy. Loss of cysteine content in the FBN1 protein was associated with larger aortic root dimensions.

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.

Expanding the genetic and phenotypic spectrum of ACTA2-related vasculopathies in a Dutch cohort

PURPOSE

Heterozygous pathogenic/likely pathogenic (P/LP) variants in the ACTA2 gene confer a high risk for thoracic aortic aneurysms and aortic dissections. This retrospective multicenter study elucidates the clinical outcome of ACTA2-related vasculopathies.

METHODS

Index patients and relatives with a P/LP variant in ACTA2 were included. Data were collected through retrospective review of medical records using a standardized questionnaire.

RESULTS

A total of 49 individuals from 28 families participated in our study. In total, 20 different ACTA2 variants were detected. Aortic events occurred in 65% of the cases (78.6% index patients and 47.6% relatives). Male sex and hypertension emerged as significantly associated with aortic events. Of 20 individuals, 5 had an aortic diameter of <45 mm (1.77 inches) at the time of the type A dissection. Mean age at first aortic event was 49.0 ± 12.4 years. Severe surgical complications for type A and type B dissection occurred in 25% and 16.7% of the cases and in-hospital mortality rates were 9.5% and 0%, respectively.

CONCLUSION

P/LP ACTA2 variants are associated with an increased risk for an aortic event and age-related penetrance, which emphasizes the importance of early recognition of the disease. Caregivers should be aware of the risk for aortic dissections, even in individuals with aortic diameters within the normal range.

Marfan syndrome and adolescent idiopathic scoliosis patients have similar 90-day postoperative outcomes and 5-year reoperation rates after spinal deformity surgery

PURPOSE

Outcomes after spinal deformity surgery in patients with Marfan syndrome (MFS) are poorly characterized given the rarity of the condition. Updated analyses from nationally representative samples, and comparison to outcomes after more commonly performed procedures for conditions such as adolescent idiopathic scoliosis (AIS) could help define the relative risks.

METHODS

Using the 2010-2020 PearlDiver administrative databases, patients who underwent posterior spinal fusion for > 7 segments were extracted. MFS patients were matched 1:4 to AIS patients based on age, sex, and Elixhauer comorbidity index (ECI). Ninety-day outcomes and 5-year reoperation rates were compared. Significance was set at p < 0.05.

RESULTS

In total, 206 MFS patients were matched to 825 AIS patients. After adjusting for age, sex, and ECI, multivariate odds ratios (OR) for 90-day any, serious, and minor adverse events, as well as readmissions, were not significantly different for those with MFS compared to those with AIS (p > 0.05 for each). Five-year reoperation rates were also not significantly different (13.1% for the MFS cohort and 13.0% for the AIS cohort (no difference by log-rank, p = 0.9).

CONCLUSION

While deformity surgery is much less commonly performed for MFS than AIS, it is not uncommonly considered for patients with this condition. Despite some known technical challenges for MFS deformity surgery, the current study leveraged a large, national database to find that 90-day adverse events and 5-year reoperations were not different for matched MFS and AIS patients undergoing deformity surgery. For select patients, these findings should be useful for surgical planning and patient counseling.

Comparability of different Z-score equations for aortic root dimensions in children with Marfan syndrome

BACKGROUND

Aortic root dilation is a major complication of Marfan syndrome and is one of the most important criteria in establishing the diagnosis. Currently, different echocardiographic nomograms are used to calculate aortic root Z-scores. The aim of the present study was to assess the potential differences in aortic root measurements when aortic root Z-scores were obtained in a cohort of paediatric Marfan patients using several published nomograms.

METHODS

In a cohort of 100 children with Marfan syndrome, Z-scores for aortic root dimensions were calculated according to the nomograms of Pettersen et al, Gautier et al, Colan et al, and Lopez et al. Bland-Altman plots were used to estimate mean differences in Z-scores and to establish limits of agreement.

RESULTS

The mean Z-score of the sinus of Valsalva for Lopez et al was significantly higher compared to Gautier et al (p < 0.01) and Pettersen et al (p = 0.03). The nomogram of Lopez et al resulted in substantially higher Z-scores in patients with a large sinus of Valsalva diameter. Thirty-five percentage of the studied patients would have a Z-score ≥ 2 using Lopez et al compared to 20% for Pettersen et al, 21% for Gautier et al, and 33% for Colan et al.

CONCLUSION

The currently available nomograms for calculating Z-scores of aortic dilation in children with Marfan syndrome lead to clinically relevant differences in Z-scores, especially in children with a relative large aortic root diameter. This could have impact on both the diagnosis and treatment of patients with Marfan syndrome.

Left ventricular function and cardiac valvar annular dimensions among children with sickle cell anemia compared to those with hemoglobin AA type in Enugu, Nigeria

Background

Enumerating the relationship between cardiac structures, function and chamber sizes in children with sickle cell anemia would help in delineating some cardiovascular abnormalities which will aid the Pediatric cardiologist and the cardiac surgeons in a number of decision-making situations.

Objectives

The objectives of this study are to assess the dimension of cardiac structures and left ventricular function in children with sickle cell anemia in steady state and controls using echocardiography.

Methods

A cross-sectional prospective study that assessed cardiac structures and left ventricular function among fifty-one children with sickle cell anemia (HBSS) and compared with fifty children with HB AA type serving as controls.

Results

A significant high proportion of children with sickle cell anemia had abnormal Valvar dimension and left ventricular function above two standard deviations (2-SD) from the mean of the standard population compared to the control group, showing a statistically significant difference (χ2 = 10.42, p= 0.001).

All the mean annular valves diameter, left ventricular internal dimension in systole and diastole, inter-sinus distance diameter and sinu-tubular junction diameter are higher in children with sickle cell anemia than controls and this is statistically significant. (p<0.005).

Conclusion

This result shows that children with sickle cell anemia have increased valvar size diameter compared with those with normal hemoglobin type. A significantly higher proportion of respondents in type SS group had abnormal left ventricular systolic and diastolic dysfunction when compared with those in type AA group.

Marfan syndrome

Marfan syndrome (MFS) is an autosomal dominant, age-related but highly penetrant condition with substantial intrafamilial and interfamilial variability. MFS is caused by pathogenetic variants in FBN1, which encodes fibrillin-1, a major structural component of the extracellular matrix that provides support to connective tissues, particularly in arteries, the pericondrium and structures in the eye. Up to 25% of individuals with MFS have de novo variants. The most prominent manifestations of MFS are asymptomatic aortic root aneurysms, aortic dissections, dislocation of the ocular lens (ectopia lentis) and skeletal abnormalities that are characterized by overgrowth of the long bones. MFS is diagnosed based on the Ghent II nosology; genetic testing confirming the presence of a FBN1 pathogenetic variant is not always required for diagnosis but can help distinguish MFS from other heritable thoracic aortic disease syndromes that can present with skeletal features similar to those in MFS. Untreated aortic root aneurysms can progress to life-threatening acute aortic dissections. Management of MFS requires medical therapy to slow the rate of growth of aneurysms and decrease the risk of dissection. Routine surveillance with imaging techniques such as transthoracic echocardiography, CT or MRI is necessary to monitor aneurysm growth and determine when to perform prophylactic repair surgery to prevent an acute aortic dissection.

Risk reduction and pharmacological strategies to prevent progression of aortic aneurysms

INTRODUCTION

While size thresholds exist to determine when aortic aneurysms warrant surgical intervention, there is no consensus on how best to treat this disease before aneurysms reach the threshold for intervention. Since a landmark study in 1994 first suggested ß-blockers may be useful in preventing aortic aneurysm growth, there has been a surge in research investigating different pharmacologic therapies for aortic aneurysms - with very mixed results.

AREAS COVERED

We have reviewed the existing literature on medical therapies used for thoracic and abdominal aortic aneurysms in humans. These include ß-blockers, angiotensin II receptor blockers, and angiotensin-converting enzyme inhibitors as well as miscellaneous drugs such as tetracyclines, macrolides, statins, and anti-platelet medications.

EXPERT OPINION

While multiple classes of drugs have been explored for risk reduction in aneurysm disease, with few exceptions results have been disappointing with an abundance of contradictory findings. The vast majority of studies have been done in patients with abdominal aortic aneurysms or thoracic aortic aneurysm patients with Marfan Syndrome. There exists a striking gap in the literature when it comes to pharmacologic management of non-Marfan Syndrome patients with thoracic aortic aneurysms. Given the differences in pathogenesis, this is an important future direction for aortic aneurysm research.

Personalised external aortic root support (PEARS) to stabilise an aortic root aneurysm

Patients with congenitally determined aortic root aneurysms are at risk of aortic valve regurgitation, aortic dissection, rupture and death. Personalised external aortic root support (PEARS) may provide an alternative to aortic root replacement. This was a multi-centre, prospective cohort of all consecutive patients who received ExoVasc mesh implants for a dilated aortic root between 2004 and 2017. Baseline and peri-operative characteristics, as well as early postoperative outcomes are described, and time-related survival and re-operation free survival are estimated using the Kaplan-Meier method. From 2004 through 2017, 117 consecutive patients have received ExoVasc mesh implants for aortic root aneurysm. The inclusion criteria were an aortic root/sinus of Valsalva and ascending aorta with asymptomatic dilatation of between 40 and 50 mm in diameter in patients aged 16 years or more. Patients with more than mild aortic regurgitation were excluded. There was one early death. The length of stay was within seven days in 75% of patients. In conclusion, the operation achieves the objectives of valve-sparing root replacement. PEARS may be seen as a low-risk conservative operation, which can be applied earlier on in the disease process, and which is complementary to more invasive procedures, such as valve-sparing root replacement or total root replacement.

Marfan syndrome revisited: From genetics to the clinic

Marfan syndrome is an autosomal dominant connective tissue disease with an estimated incidence of 1 in 5000 individuals. In 90% of cases it is caused by mutations in the gene for fibrillin-1, the main constituent of extracellular microfibrils. Studies on animal models of Marfan syndrome have revealed that fibrillin-1 mutations interfere with local TGF-β signaling, in addition to impairing tissue integrity. The cardinal features involve the cardiovascular, ocular and skeletal systems. The diagnosis of Marfan syndrome is made according to the revised Ghent nosology. Early identification and appropriate management are critical for patients with Marfan syndrome, who are prone to the life-threatening cardiovascular complications of aortic aneurysms and aortic dissection. The standard treatment includes prophylactic beta-blockers in order to slow down dilation of the ascending aorta, and prophylactic aortic surgery. The success of current medical and surgical treatment of aortic disease in Marfan syndrome has substantially improved mean life expectancy, extending it above 72 years. This review aims to provide an overview of this hereditary disorder.

Rupture of a Type B Aortic Dissection in a Postpartum Patient with Marfan Syndrome

Background  Pregnant women with Marfan syndrome (MFS) are known to be at increased risk of aortic dissection; however, cases of aortic rupture are extremely rare. There is lack of consensus on the exact site and size of aortic diameter measurement that increases this risk, and whether this applies to both Type A and Type B dissections. Case  A 23-year-old G2P1001 with known Marfan syndrome who underwent an uncomplicated antepartum and intrapartum course. She experienced persistent backache 10 days postpartum that led to the diagnosis of Stanford Type B dissection. The patient was hospitalized for close observation. Dissection progressed to aortic rupture within 24 hours that required emergent thoracic endovascular aortic repair. She had an uncomplicated postoperative course. Conclusion  Our report demonstrates rupture of a known aortic dissection within a very short time in the postpartum period. The case highlights the importance of patient education and close surveillance especially in the postpartum period. It also brings home the value of imaging of the whole aorta rather than focusing on the ascending alone. Multidisciplinary care and timely diagnosis and intervention likely led to the favorable outcome in our case.

Size and dissection: what is the relation?

Thoracic aortic aneurysm is a complex disease. The consequences of such silent and indolent disease include acute aortic syndrome if not recognized early and treated appropriately. Aortic aneurysm size was a reliable clinical marker to aid clinical intervention; however, aneurysm growth is variable and is influenced by many factors such as age, presence of connective tissue disorders, genetic disorders, hypertension, inflammatory conditions of the aorta, autoimmune diseases, smoking, and history of previous cardiac surgery. Therefore, aortic size became a non-specific disease surrogate and prediction tool on outcome and intervention. In this review article, we examined the current literature for evidence about aneurysm size and its relation to type A aortic dissection.

In vivo characterization of doxycycline-mediated protection of aortic function and structure in a mouse model of Marfan syndrome-associated aortic aneurysm

Aortic aneurysm is the most life-threatening complication in Marfan syndrome (MFS) patients. Doxycycline, a nonselective matrix metalloproteinases inhibitor, was reported to improve the contractile function and elastic fiber structure and organization in a Marfan mouse aorta using ex vivo small chamber myography. In this study, we assessed the hypothesis that a long-term treatment with doxycycline would reduce aortic root growth, improve aortic wall elasticity as measured by pulse wave velocity, and improve the ultrastructure of elastic fiber in the mouse model of MFS. In our study, longitudinal measurements of aortic root diameters using high-resolution ultrasound imaging display significantly decreased aortic root diameters and lower pulse wave velocity in doxycycline-treated Marfan mice starting at 6 months as compared to their non-treated MFS counterparts. In addition, at the ultrastructural level, our data show that long-term doxycycline treatment corrects the irregularities of elastic fibers within the aortic wall of Marfan mice to the levels similar to those observed in control subjects. Our findings underscore the key role of matrix metalloproteinases during the progression of aortic aneurysm, and provide new insights into the potential therapeutic value of doxycycline in blocking MFS-associated aortic aneurysm.

The transition of pediatric Marfan patients to adult care: a challenge and its risks

Background

Care for patients with Marfan syndrome (MFS) has improved substantially in recent decades. Increasing clinical knowledge and genetic analysis allow early diagnosis of the disease in childhood. Because of the earlier initiation to preventive and medical treatment, patients' life expectancy has risen. To ensure optimal care, pediatric patients require a safe follow-up regime, multidisciplinary care, and a safe transition to adult care.

Methods

We collected a sample of 149 pediatric Marfan patients, of whom 34 patients had already been transferred to adult care or who were currently transitioning. First, we evaluated clinical aspects of patients that manifest in childhood and are present in the transition process. Second, we analyzed the transition process itself.

Results

We found age-dependent manifestation of organ pathologies. Dilatation of the sinus of Valsalva showed a particularly high prevalence during the transition process and 62% of patients required medical treatment. Mean onset of aortic root dilatation was 9.9±5.8 years. Concerning systemic manifestation in MFS skin striae, wrist and thumb sign, and reduced elbow extension occurred significantly more often in patients who were transitioning than in younger children with MFS. All other clinical Marfan features showed an increased prevalence in patients who were transitioning compared with younger patients. In our cohort, transition was successful in 20 patients (58.9%), 12 patients (35.3%) are still in the transition process and 2 patients (5.9%) were lost to follow up.

Conclusions

Marfan patients in the transition process are already under a chronic disease condition with a high onset of especially cardiovascular pathologies. Although early medical treatment in childhood is effective, the pathologies of the connective tissue require lifelong attention and influence life in many ways. The big challenge during transition is the double change of responsibility from the parents and pediatric doctor to the patient and adult doctor. Consequently, patients in transition process require special attention and close contact with the doctor and the family. A reevaluation by the supervising pediatric Marfan specialist of the successful transition to adult care is indispensable before the pediatric care of Marfan patients is completed.

Differences in Cardiovascular Manifestation of Marfan Syndrome Between Children and Adults

Marfan syndrome (MFS) is a connective tissue disorder characterized by a broad range of clinical manifestations. Cardiovascular involvement is the most life-threatening aspect of the syndrome. Although abnormalities within the cardiovascular system in adults are well documented, there is still a paucity of data regarding manifestation of MFS in childhood. The aim of the study was to compare cardiovascular manifestation of MFS between children and adults. The study population consisted of 236 patients (144 children and 92 adults), who were referred to our department with suspicion of MFS. All patients underwent complete clinical evaluation in order to confirm the diagnosis of MFS according to the modified Ghent criteria. MFS was diagnosed in 101 (44 children and 57 adults) out of the 236 patients. The other patients were diagnosed with Ehlers-Danlos syndrome, Loeys-Dietz syndrome, MASS phenotype, ectopia lentis syndrome, marfanoid habitus and other rare syndromes. The most common cardiovascular abnormality was aortic root dilatation (81.19% of patients). It was found that both adults and children had similar high rates of aortic root dilatation. Similarly, there was no significant difference with regard to the prevalence of aortic valve regurgitation and mitral valve prolapse among children and adults. These findings equivocally indicate that the aforementioned abnormalities develop in early childhood, therefore, they may be used in the early identification of patients with MFS. Other assessed abnormalities, which included mitral valve regurgitation, pulmonary artery dilation, aneurysms of aortic arch, descending thoracic aorta and abdominal aorta were found mostly in adults, and thus, are of less use in the early detection of MFS.

Predictors of Rapid Aortic Root Dilation and Referral for Aortic Surgery in Marfan Syndrome

Few data exist regarding predictors of rapid aortic root dilation and referral for aortic surgery in Marfan syndrome (MFS). To identify independent predictors of the rate of aortic root (AoR) dilation and referral for aortic surgery, we investigated the data from the Pediatric Heart Network randomized trial of atenolol versus losartan in young patients with MFS. Data were analyzed from the echocardiograms at 0, 12, 24, and 36 months read in the core laboratory of 608 trial subjects, aged 6 months to 25 years, who met original Ghent criteria and had an AoR z-score (AoRz) > 3. Repeated measures linear and logistic regressions were used to determine multivariable predictors of AoR dilation. Receiver operator characteristic curves were used to determine cut-points in AoR dilation predicting referral for aortic surgery. Multivariable analysis showed rapid AoR dilation as defined by change in AoRz/year > 90th percentile was associated with older age, higher sinotubular junction z-score, and atenolol use (R2 = 0.01) or by change in AoR diameter (AoRd)/year > 90th percentile with higher sinotubular junction z-score and non-white race (R2 = 0.02). Referral for aortic root surgery was associated with higher AoRd, higher ascending aorta z-score, and higher sinotubular junction diameter:ascending aorta diameter ratio (R2 = 0.17). Change in AoRz of 0.72 SD units/year had 42% sensitivity and 92% specificity and change in AoRd of 0.34 cm/year had 38% sensitivity and 95% specificity for predicting referral for aortic surgery. In this cohort of young patients with MFS, no new robust predictors of rapid AoR dilation or referral for aortic root surgery were identified. Further investigation may determine whether generalized proximal aortic dilation and effacement of the sinotubular junction will allow for better risk stratification. Rate of AoR dilation cut-points had high specificity, but low sensitivity for predicting referral for aortic surgery, limiting their clinical use. Clinical Trial Number ClinicalTrials.gov number, NCT00429364.

Consideration of Sex Differences in Design and Reporting of Experimental Arterial Pathology Studies-Statement From ATVB Council

There are many differences in arterial diseases between men and women, including prevalence, clinical manifestations, treatments, and prognosis. The new policy of the National Institutes of Health, which requires the inclusion of sex as a biological variable for preclinical studies, aims to foster new mechanistic insights and to enhance our understanding of sex differences in human diseases. The purpose of this statement is to suggest guidelines for designing and reporting sex as a biological variable in animal models of atherosclerosis, thoracic and abdominal aortic aneurysms, and peripheral arterial disease. We briefly review sex differences of these human diseases and their animal models, followed by suggestions on experimental design and reporting of animal studies for these vascular pathologies.

Vascular Smooth Muscle Cells and Arterial Stiffening: Relevance in Development, Aging, and Disease

The cushioning function of large arteries encompasses distension during systole and recoil during diastole which transforms pulsatile flow into a steady flow in the microcirculation. Arterial stiffness, the inverse of distensibility, has been implicated in various etiologies of chronic common and monogenic cardiovascular diseases and is a major cause of morbidity and mortality globally. The first components that contribute to arterial stiffening are extracellular matrix (ECM) proteins that support the mechanical load, while the second important components are vascular smooth muscle cells (VSMCs), which not only regulate actomyosin interactions for contraction but mediate also mechanotransduction in cell-ECM homeostasis. Eventually, VSMC plasticity and signaling in both conductance and resistance arteries are highly relevant to the physiology of normal and early vascular aging. This review summarizes current concepts of central pressure and tensile pulsatile circumferential stress as key mechanical determinants of arterial wall remodeling, cell-ECM interactions depending mainly on the architecture of cytoskeletal proteins and focal adhesion, the large/small arteries cross-talk that gives rise to target organ damage, and inflammatory pathways leading to calcification or atherosclerosis. We further speculate on the contribution of cellular stiffness along the arterial tree to vascular wall stiffness. In addition, this review provides the latest advances in the identification of gene variants affecting arterial stiffening. Now that important hemodynamic and molecular mechanisms of arterial stiffness have been elucidated, and the complex interplay between ECM, cells, and sensors identified, further research should study their potential to halt or to reverse the development of arterial stiffness.

Associations of Age and Sex With Marfan Phenotype: The National Heart, Lung, and Blood Institute GenTAC (Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) Registry

BACKGROUND

The associations of age and sex with phenotypic features of Marfan syndrome have not been systematically examined in a large cohort of both children and adults.

METHODS AND RESULTS

We evaluated 789 Marfan patients enrolled in the National Heart, Lung, and Blood Institute GenTAC (Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions) Registry (53% male; mean age 31 [range: 1-86 years]). Females aged ≥15 and males aged ≥16 years were considered adults based on average age of skeletal maturity. Adults (n=606) were more likely than children (n=183) likely to have spontaneous pneumothorax, scoliosis, and striae but were comparable in revised Ghent systemic score, ectopia lentis, and most phenotypic features, including prevalence of aortic root dilatation. Prophylactic aortic root replacement and mitral valve surgery were rare during childhood versus adulthood (2% versus 35% and 1% versus 9%, respectively, both P<0.0001). Adult males were more likely than females to have aortic root dilatation (92% versus 84%), aortic regurgitation (55% versus 36%), and to have undergone prophylactic aortic root replacement (47% versus 24%), all P<0.001. Prevalence of previous aortic dissection tended to be higher in males than females (25% versus 18%, P=0.06); 44% of dissections were type B. Type B dissection was strongly associated with previous prophylactic aortic root replacement.

CONCLUSIONS

Pulmonary, skeletal, and aortic complications, but not other phenotypic features, are more prevalent in adults than children in Marfan syndrome. Aortic aneurysms and prophylactic aortic surgery are more common in men. Aortic dissection, commonly type B, occurs in an appreciable proportion of Marfan patients, especially in men and after previous prophylactic aortic root replacement.

Florida Sleeve Procedure Is Durable and Improves Aortic Valve Function in Marfan Syndrome Patients

BACKGROUND

The Florida sleeve (FS) procedure was developed as a simplified approach for repair of functional type I aortic insufficiency secondary to aortic root aneurysm. We evaluated postoperative aortic valve function, long-term survival, and freedom from reoperation in Marfan syndrome patients who underwent the FS procedure at our center.

METHODS

All Marfan syndrome patients undergoing FS procedure from May 2002 to December 2014 were included. Echocardiography assessment included left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), ejection fraction, and degree of aortic insufficiency (none = 0, minimal = 1, mild = 2, moderate = 3, severe = 4). Social Security Death Index and primary care physicians' report were used for long-term follow-up.

RESULTS

Thirty-seven Marfan syndrome patients, 21 (56.8%) men and 16 (43%) women with mean age of 35.08 ± 13.45 years underwent FL repair at our center. There was no in-hospital or 30-day death or stroke. Two patients required reoperation due to bleeding. Patients' survival rate was 94% at 1 to 8 years. Freedom from reoperation was 100% at 8 years. Twenty-five patients had postoperative follow-up echocardiography at 1 week. Aortic insufficiency grade significantly decreased after the procedure (preoperative mean ± SD: 1.76 ± 1.2 versus 1-week postoperative mean ± SD: 0.48 ± 0.71, p < 0.001), and mean LVEDD decreased from 52.23 ± 5.29 mm to 47.53 ± 8.89 mm (p = 0.086). Changes in LVESD (35.33 ± 9.97 mm to 36.58 ± 9.82 mm, p = 0.58) and ejection fraction (57.65% ± 6.22% to 55% ± 10.83%, p = 0.31) were not significant.

CONCLUSIONS

The FS procedure can be performed safely in Marfan syndrome patients with immediate improvement in aortic valve function. Long-term survival and freedom from reoperation rates are encouraging.

Indications for Aortic Arch Intervention

Surgery of the aortic arch is arguably one of the most complex areas of cardiac surgery. Despite that, studies and guidelines have not sufficiently addressed the aortic arch specifically. In general, indications for aortic arch intervention parallel those of the ascending aorta. Herein we review indications for aortic arch intervention in various aortic pathologies based on the scant evidence available combined with surgical expertise and expert opinion.

Surgical Treatment of Siblings with Marfan Syndrome

Rupture of an ascending aortic aneurysm is the most common cause of death in patients with Marfan syndrome, while type-A aortic dissection is the second most common fatal lesion. The aortic root dimension and the rate at which it increases are the best indications for surgical treatment. We regard aortic enlargement to 5.5 cm as the upper limit of safety and we are inclined to advocate surgery at an earlier stage in high-risk families. We report our results of the surgical management of aortic aneurysm in the two siblings; a third sibling is currently being followed medically.

CT and MR imaging of the thoracic aorta

At present time, both CT and MRI are valuable techniques in the study of the thoracic aorta. Nowadays, CT represents the most widely employed technique for the study of the thoracic aorta. The new generation CTs show sensitivities up to 100% and specificities of 98-99%. Sixteen and wider row detectors provide isotropic pixels, mandatory for the ineludible longitudinal reconstruction. The main limits are related to the X-ray dose expoure and the use of iodinated contrast media. MRI has great potential in the study of the thoracic aorta. Nevertheless, if compared to CT, acquisition times remain longer and movement artifact susceptibility higher. The main MRI disadvantages are claustrophobia, presence of ferromagnetic implants, pacemakers, longer acquisition times with respect to CT, inability to use contrast media in cases of renal insufficiency, lower spatial resolution and less availability than CT. CT is preferred in the acute aortic disease. Nevertheless, since it requires iodinated contrast media and X-ray exposure, it may be adequately replaced by MRI in the follow up of aortic diseases. The main limitation of MRI, however, is related to the scarce visibility of stents and calcifications.

Aortic Dissection in Patients With Genetically Mediated Aneurysms: Incidence and Predictors in the GenTAC Registry

BACKGROUND

Aortic dissection (AoD) is a serious complication of thoracic aortic aneurysm (TAA). Relative risk for AoD in relation to TAA etiology, incidence, and pattern after prophylactic TAA surgery are poorly understood.

OBJECTIVES

This study sought to determine the incidence, pattern, and relative risk for AoD among patients with genetically associated TAA.

METHODS

The population included adult GenTAC participants without AoD at baseline. Standardized core laboratory tests classified TAA etiology and measured aortic size. Follow-up was performed for AoD.

RESULTS

Bicuspid aortic valve (BAV) (39%) and Marfan syndrome (MFS) (22%) were the leading diagnoses in the studied GenTAC participants (n = 1,991). AoD occurred in 1.6% over 3.6 ± 2.0 years; 61% of AoD occurred in patients with MFS. Cumulative AoD incidence was 6-fold higher among patients with MFS (4.5%) versus others (0.7%; p < 0.001). MFS event rates were similarly elevated versus those in patients with BAV (0.3%; p < 0.001). AoD originated in the distal arch or descending aorta in 71%; 52% of affected patients, including 68% with MFS, had previously undergone aortic grafting. In patients with proximal aortic surgery, distal aortic size (descending thoracic, abdominal aorta) was larger among patients with AoD versus those without AoD (both p < 0.05), whereas the ascending aorta size was similar. Conversely, in patients without previous surgery, aortic root size was greater in patients with subsequent AoD (p < 0.05), whereas distal aortic segments were of similar size. MFS (odds ratio: 7.42; 95% confidence interval: 3.43 to 16.82; p < 0.001) and maximal aortic size (1.86 per cm; 95% confidence interval: 1.26 to 2.67; p = 0.001) were independently associated with AoD. Only 4 of 31 (13%) patients with AoD had pre-dissection images that fulfilled size criteria for prophylactic TAA surgery at a subsequent AoD site.

CONCLUSIONS

Among patients with genetically associated TAA, MFS augments risk for AoD even after TAA grafting. Although increased aortic size is a risk factor for subsequent AoD, events typically occur below established thresholds for prophylactic TAA repair.

A Decade of Discovery in the Genetic Understanding of Thoracic Aortic Disease

Aortic aneurysms are responsible for a significant number of all deaths in Western countries. In this review we provide a perspective on the important progress made over the past decade in the understanding of the genetics of this condition, with an emphasis on the more frequent forms of vascular smooth muscle and transforming growth factor β (TGF-β) signalling alterations. For several nonsyndromic and syndromic forms of thoracic aortic disease, a genetic basis has now been identified, with 3 main pathomechanisms that have emerged: perturbation of the TGF-β signalling pathway, disruption of the vascular smooth muscle cell (VSMC) contractile apparatus, and impairment of extracellular matrix synthesis. Because smooth muscle cells and proteins of the extracellular matrix directly regulate TGF-β signalling, this latter pathway emerges as a key component of thoracic aortic disease initiation and progression. These discoveries have revolutionized our understanding of thoracic aortic disease and provided inroads toward gene-specific stratification of treatment. Last, we outline how these genetic findings are translated into novel pharmaceutical approaches for thoracic aortic disease.

Normal Values and Differences in Ascending Aortic Diameter in a Healthy Population of Adults as Measured by the Pediatric versus Adult American Society of Echocardiography Guidelines

BACKGROUND

There is a lack of uniformity across echocardiographic society guidelines as to how the diameter of the ascending aorta is to be measured. The aims of this study were to compare measurements done using the diastolic leading edge-to-leading edge and systolic inner edge-to-inner edge (SIE) techniques in a large cohort of healthy adult individuals and to report the normal values for adults using the SIE technique.

METHODS

Aortic diameters obtained according to the two guideline recommendations at the aortic annuls, sinuses of Valsalva, sinotubular junction, and ascending aorta in 1,148 healthy adult volunteers were compared. Bland-Altman analysis, paired t tests, and intraclass correlation coefficients were evaluated at each segment. SIE values are reported as normative data, according to age, gender, and body surface area.

RESULTS

The diastolic leading edge-to-leading edge convention yielded smaller diameters (compared with SIE) at the aortic annulus and ascending aorta and larger diameters at the sinus of Valsalva and sinotubular junction (P < .001 for all). There was excellent correlation between these techniques, with intraclass correlation coefficients of 0.88 to 0.96. Interobserver variability was minimal and similar for both techniques. Using the SIE technique, diameters were larger for men and increased with age and larger body surface area.

CONCLUSIONS

Although there was a statistically significant difference in aortic diameter measures between the two conventions used, this difference was very small and correlations were excellent, suggesting that the difference has no clinical significance. The authors recommend that a standard convention be adopted within the American Society of Echocardiography and across all professional cardiovascular imaging societies for consistency and improved communication.

Unruptured Sinus of Valsalva Aneurysm with Right Ventricular Outflow Tract Obstruction and Supracristal Ventricular Septal Defect: A Rare Case

Unruptured right sinus of Valsalva aneurysm that causes severe obstruction of the right ventricular outflow tract is extremely rare. We describe the case of a 47-year-old woman who presented with exertional dyspnea. Upon investigation, we discovered an unruptured right sinus of Valsalva aneurysm with associated right ventricular outflow tract obstruction and a supracristal ventricular septal defect. To our knowledge, only 2 such cases have previously been reported in the medical literature. Although treatment of unruptured sinus of Valsalva aneurysm remains debatable, surgery should be considered for extremely large aneurysms or for progressive enlargement of the aneurysm on serial evaluation. Surgery was undertaken in our patient because there was clear evidence of right ventricular outflow tract obstruction, right-sided heart dilation, and associated exertional dyspnea.