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

Z-score evaluation and inferences for management of aortopathy patients

Echocardiographic Z-score models play a crucial role in defining cardiac pathology in paediatric patients. There are multiple models that practitioners utilize in the United States without guiding principles to standardize their use. Discrepant interpretations can occur depending on the model chosen, even if standardized Z-score cutoffs are applied. In this study, a survey was developed to assess pediatric cardiologists' use of Z-score systems when evaluating and treating patients with isolated bicuspid aortic valve. The majority of respondents reported using Z-score cutoffs to evaluate the degree of aortic root and ascending aorta dilation. For the aortic root, mild, moderate, and severe dilation averaged at 2.13 (SD = 0.32), 3.59 (SD = 0.49), and 5.11 (SD = 0.84), respectively. Similar cutoffs were reported for determining ascending aorta dilation. A large proportion of respondents primarily used the Boston system (36%, 18/50) or Boston and Pediatric Heart Network systems together (36%, 18/50). There were also differences in management decisions, such as implementing competitive sports restrictions, based on Z-scores and the 2015 Task Force 7 Bethesda exercise guidelines. These survey results demonstrate variability that exists among paediatric cardiologists in their use of Z-scores for describing aortic root and ascending aorta dilation in patients with isolated bicuspid aortic valve and suggests the need for implementation of national guidelines for Z-score usage.

Advances in Cardiovascular Multimodality Imaging in Patients with Marfan Syndrome

Marfan syndrome (MFS) is a genetic disorder affecting connective tissue, often leading to cardiovascular complications such as aortic aneurysms and mitral valve prolapse. Cardiovascular multimodality imaging plays a crucial role in the diagnosis, monitoring, and management of MFS patients. This review explores the advancements in echocardiography, cardiovascular magnetic resonance (CMR), cardiac computed tomography (CCT), and nuclear medicine techniques in MFS. Echocardiography remains the first-line tool, essential for assessing aortic root, mitral valve abnormalities, and cardiac function. CMR provides detailed anatomical and functional assessments without radiation exposure, making it ideal for long-term follow-up. CT offers high-resolution imaging of the aorta, crucial for surgical planning, despite its ionizing radiation. Emerging nuclear medicine techniques, though less common, show promise in evaluating myocardial involvement and inflammatory conditions. This review underscores the importance of a comprehensive imaging approach to improve outcomes and guide interventions in MFS patients. It also introduces novel aspects of multimodality approaches, emphasizing their impact on early detection and management of cardiovascular complications in MFS.

Management of aortic disease in children with FBN1-related Marfan syndrome

Marfan syndrome (MFS) is a hereditary connective tissue disorder with an estimated prevalence of 1:5000-1:10 000 individuals. It is a pleiotropic disease characterized by specific ocular, cardiovascular, and skeletal features. The most common cardiovascular complication is aortic root dilatation which untreated can lead to life-threatening aortic root dissection, mainly occurring in adult patients. Prompt diagnosis, appropriate follow-up, and timely treatment can prevent aortic events. Currently there are no specific recommendations for treatment of children with MFS, and management is greatly based on adult guidelines. Furthermore, due to the scarcity of studies including children, there is a lack of uniform treatment across different centres. This consensus document aims at bridging these gaps of knowledge. This work is a joint collaboration between the paediatric subgroup of the European Network of Vascular Diseases (VASCERN, Heritable Thoracic Aortic Disease Working Group) and the Association for European Paediatric and Congenital Cardiology (AEPC). A group of experts from 12 different centres and 8 different countries participated in this effort. This document reviews four main subjects, namely, (i) imaging of the aorta at diagnosis and follow-up, (ii) recommendations on medical treatment, (iii) recommendations on surgical treatment, and (iv) recommendations on sport participation.

Aortic Dilatation in Children and Young People With ADPKD

Introduction

Aortic root dilatation is a reported cardiovascular sequela seen in children and young people (CYP) with chronic kidney disease (CKD) but has yet to be described in those with autosomal dominant polycystic kidney disease (ADPKD).

Methods

Single center, cross-sectional study in a dedicated ADPKD clinic. Echocardiograms were evaluated for the presence of dilatation (defined by a z-score ≥2 [≥99th percentile] SDs from the mean) at 4 standardized locations, namely the aortic valve annulus, sinuses of Valsalva (SoV), sinotubular junction (STJ), and the ascending aorta. Measurements were compared with a control group to assess prevalence, severity, and determinants of aortic dilatation.

Results

Ninety-seven children, median age (interquartile range) of 9.3 (6.1, 13.6) years were compared with 19 controls without ADPKD or other CKD. The prevalence of dilatation ranged from 5.2% to 17% in ADPKD, depending on anatomical location with no aortic dilatation identified in the control group. In multivariable regression, aortic root dilatation was significantly associated with cyst burden at the aortic valve annulus and SoV (β = 0.42 and β = 0.39, both P < 0.001), with age at SoV (β = -0.26, P = 0.02), systolic blood pressure (SBP) z-score at SoV (β = -0.20, P = 0.04) and left ventricular mass index (LVMI) at SoV and STJ (β = 0.24, P = 0.02 and β = 0.25, P = 0.03, respectively) following adjustment for age, sex (male or female), body mass index (BMI) z-score, estimated glomerular filtration rate (eGFR), SBP z-score, and LVMI.

Conclusion

Our data suggests increased prevalence of aortic root and ascending aortic dilatation in CYP with ADPKD compared with controls. Further studies are needed to understand the pathogenesis and its contribution to the high cardiovascular morbidity in ADPKD.

Unique Features of Cardiovascular Involvement and Progression in Children with Marfan Syndrome Justify Dedicated Multidisciplinary Care

Marfan syndrome (MIM: # 154700; MFS) is an autosomal dominant disease representing the most common form of heritable connective tissue disorder. The condition presents variable multiorgan expression, typically involving a triad of cardiovascular, eye, and skeletal manifestations. Other multisystemic features are often underdiagnosed. Moreover, the disease is characterized by age related penetrance. Diagnosis and management of MFS in the adult population are well-described in literature. Few studies are focused on MFS in the pediatric population, making the clinical approach (cardiac and multiorgan) to these cases challenging both in terms of diagnosis and serial follow-up. In this review, we provide an overview of MFS manifestations in children, with extensive revision of major organ involvement (cardiovascular ocular and skeletal). We attempt to shed light on minor aspects of MFS that can have a significant progressive impact on the health of affected children. MFS is an example of a syndrome where an early personalized approach to address a dynamic, genetically determined condition can make a difference in outcome. Applying an early multidisciplinary clinical approach to MFS cases can prevent acute and chronic complications, offer tailored management, and improve the quality of life of patients.

Aortic Dilatation in Pediatric Patients with Bicuspid Aortic Valve: How the Choice of Nomograms May Change Prevalence

BACKGROUND

Aortic dilation (AoD) is commonly reported in patients with bicuspid aortic valve (BAV) and has been related to flow abnormalities and genetic predisposition. AoD-related complications are reported to be extremely rare in children. Conversely, an overestimate of AoD related to body size may lead to excess diagnoses and negatively impact quality of life and an active lifestyle. In the present study, we compared the diagnosis performance of the newly introduced Q-score (based on a machine-learning algorithm) versus the traditional Z-score in a large consecutive pediatric cohort with BAV.

MATERIALS AND METHODS

Prevalence and progression of AoD were evaluated in 281 pediatric patients ages > 5 and < 18 years at first observation, 249 of whom had isolated BAV and 32 had BAV associated with aortic coarctation (CoA-BAV). An additional group of 24 pediatric patients with isolated CoA was considered. Measurements were made at the level of the aortic annulus, Valsalva sinuses, sinotubular aorta, and proximal ascending aorta. Both Z-scores using traditional nomograms and the new Q-score were calculated at baseline and at followup (mean 4.5 years).

RESULTS

A dilation of the proximal ascending aorta was suggested by traditional nomograms (Z-score > 2) in 31.2% of patients with isolated BAV and 18.5% with CoA-BAV at baseline and in 40.7% and 33.3%, respectively, at followup. No significant dilation was found in patients with isolated CoA. Using the new Q-score calculator, ascending aorta dilation was detected in 15.4% of patients with BAV and 18.5% with CoA-BAV at baseline and in 15.8% and 3.7%, respectively, at followup. AoD was significantly related to the presence and degree of aortic stenosis (AS) but not to aortic regurgitation (AR). No AoD-related complications occurred during the followup.

CONCLUSIONS

Our data confirm the presence of ascending aorta dilation in a consistent subgroup of pediatric patients with isolated BAV, with progression during followup, while AoD was less common when CoA was associated with BAV. A positive correlation was found with the prevalence and degree of AS, but not with AR. Finally, the nomograms used may significantly influence the prevalence of AoD, especially in children, with a possible overestimation by traditional nomograms. This concept requires prospective validation in long-term followup.

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.

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.