Long-Term Risk Factors for Dilatation of the Proximal Aorta in a Large Cohort of Children With Bicuspid Aortic Valve

Bicuspid Aortic Valve in Children and Young Adults for Cardiologists and Cardiac Surgeons: State-of-the-Art of Literature Review

Bicuspid aortic valve disease is the most prevalent congenital heart disease, affecting up to 2% of the general population. The presentation of symptoms may vary based on the patient's anatomy of fusion, with transthoracic echocardiography being the primary diagnostic tool. Bicuspid aortic valves may also appear with concomitant aortopathy, featuring fundamental structural changes which can lead to valve dysfunction and/or aortic dilatation over time. This article seeks to give a comprehensive overview of the presentation, treatment possibilities and long-term effects of this condition. The databases MEDLINE, Embase, and the Cochrane Library were searched using the terms "endocarditis" or "bicuspid aortic valve" in combination with "epidemiology", "pathogenesis", "manifestations", "imaging", "treatment", or "surgery" to retrieve relevant articles. We have identified two types of bicuspid aortic valve disease: aortic stenosis and aortic regurgitation. Valve replacement or repair is often necessary. Patients need to be informed about the benefits and drawbacks of different valve substitutes, particularly with regard to life-long anticoagulation and female patients of childbearing age. Depending on the expertise of the surgeon and institution, the Ross procedure may be a viable alternative. Management of these patients should take into account the likelihood of somatic growth, risk of re-intervention, and anticoagulation risks that are specific to the patient, alongside the expertise of the surgeon or centre. Further research is required on the secondary prevention of patients with bicuspid aortic valve (BAV), such as lifestyle advice and antibiotics to prevent infections, as the guidelines are unclear and lack strong evidence.

Assessment of abnormal transvalvular flow and wall shear stress direction for pediatric/young adults with bicuspid aortic valve: a cross-sectional 4D flow study

BACKGROUND

Aortic dilation is seen in pediatric/young adult patients with bicuspid aortic valve (BAV), and hemodynamic markers to predict aortic dilation are necessary for monitoring. Although promising hemodynamic metrics, such as abnormal wall shear stress (WSS) magnitude, have been proposed for adult BAV patients using 4D flow cardiovascular magnetic resonance, those for pediatric BAV patients have less frequently been reported, partly due to scarcity of data to define normal WSS range. To circumvent this challenge, this study aims to investigate if a recently proposed 4D flow-based hemodynamic measurement, abnormal flow directionality, is associated with aortic dilation in pediatric/young adult BAV patients.

METHODS

4D flow scans for BAV patients (<20 years old) and age-matched controls were retrospectively enrolled. Static segmentation for the aorta and pulmonary arteries was obtained to quantify peak systolic hemodynamics and diameters in the proximal aorta. In addition to peak velocity, wall shear stress (WSS), vorticity, helicity, and viscous energy loss, direction of aortic velocity and WSS in BAV patients was compared with that of control atlas using registration technique; angle differences of >60deg and >120deg were defined as moderately and severely abnormal, respectively. Association between the obtained metrics and normalized diameters (Z-scores) were evaluated at the sinotubular junction, mid ascending aorta, and distal ascending aorta.

RESULTS

Fifty-three BAV patients, including eighteen with history of repaired aortic coarctation, and seventeen controls were enrolled. Correlation between moderately abnormal velocity/WSS direction and aortic Z-scores was moderate to strong at the sinotubular junction and mid ascending aorta (R=0.62-0.81; p<0.001) while conventional measurements exhibited weaker correlation (|R|=0.003-0.47, p=0.009-0.99) in all subdomains. Multivariable regression analysis found moderately abnormal velocity direction and existence of aortic regurgitation (only for isolated BAV group) were independently associated with mid ascending aortic Z-scores.

CONCLUSION

Abnormal velocity and WSS directionality in the proximal aorta was strongly associated with aortic Z-scores in pediatric/young adult BAV patients.

Application of Computed Tomography Angiography in Preoperative Diagnosis of Coarctation of Aorta and Evaluation of Aortic Dilatation in Infants

OBJECTIVE

To evaluate the occurrence of aortic dilatation and its associated predictors with coarctation of the aorta (CoA) in infants using multi-slice computed tomography (MSCT).

METHODS

The clinical data of 47 infantile patients with CoA diagnosed by MSCT and 28 infantile patients with simple ventricular septal defect were analyzed retrospectively. Aortic diameters were measured at six different levels, and aortic sizes were compared by z score. The coarctation site-diaphragm ratio was used to describe the degree of narrowing. Relevant clinical data were collated and analyzed.

RESULTS

The dilation rate and z score of the ascending aorta in the severe CoA group were significantly higher than those in the mild CoA group (11 [52.38%] vs. 21 [80.77%], P=0.038 and 2.00 ± 0.48 vs. 2.36 ± 0.43, P=0.010). Pearson's correlation analysis found that the z score of the ascending aorta was negatively correlated with the coarctation site-diaphragm ratio value (r=-0.410, P=0.004). A logistic retrospective analysis found that an increased degree of coarctation was an independent predictor of aortic dilatation (adjusted odds ratio 0.002; 95% confidence interval 0.00-0.819; P=0.043). The z score of the ascending aorta in the severe CoA group was significantly higher than that in the ventricular septal defect group (P<0.05).

CONCLUSION

Most infants with CoA can also have significant dilatation of the ascending aorta, and the degree of this dilatation is related to the degree of coarctation. Assessment of aortic diameter and related malformations by MSCT can predict the risk of aortic dilatation in infants with CoA.

The Quebec Congenital Heart Disease Registry: A Model of Prospective Databank to Facilitate Research in Congenital Cardiology

Background

A national registry of congenital heart disease (CHD) would facilitate project initiation, decrease costs, increase statistical power, and avoid duplication. Establishing such registries poses numerous challenges, but the current Canadian research ecosystem in CHD is well positioned to meet them. We assessed the feasibility of building a province-wide CHD registry by automatically identifying people with CHD and extracting their native cardiac anatomy from multiple clinical data sources, without the need for manual data entry.

Methods

We designed a CHD registry of all fetuses and children with at least 1 echocardiographic report confirming CHD since 2000. We interfaced the registry with several clinical and echocardiography data sources from all paediatric cardiology programmes in Québec.

Results

We extracted 885,287 echocardiogram reports and 70,121 clinical records. We identified CHD in 43,452 children and 4682 fetuses. There were 1128 (2.3%) cases with files in multiple institutions, and patients with more complex CHD were 3 times more likely to be seen in more than 1 institution. So far, the registry has been used to build and link CHD cohorts for 7 distinct projects.

Conclusions

We demonstrated the feasibility of a baseline CHD registry in Québec without the need for manual data entry, in which other CHD research projects could be nested. This could serve as a blueprint to expand the registry and to develop an integrated approach where data gathered in caring for patients with CHD serve as data layers that incrementally contribute to a national cohort, for which data remain easily accessible and usable.

Aortic regurgitation provokes phenotypic modulation of smooth muscle cells in the normal ascending aorta

BACKGROUND

Aortic complications are more likely to occur in patients with ascending aortic aneurysms and concomitant aortic regurgitation (AR). AR may have a negative influence on the aortic wall structure even in patients with tricuspid aortic valves and absence of aortic dilatation. It is unknown whether smooth muscle cell (SMC) changes are a feature of AR-associated aortic remodeling.

METHODS

Nondilated aortic samples were harvested intraoperatively from individuals with normal aortic valves (n = 10) or those with either predominant aortic stenosis (AS) (n = 20) or AR (n = 35). Tissue from each patient was processed for immunohistochemistry or used for the extraction of medial SMCs. Tissue and cells were stained for markers of SMC contraction (alpha-smooth muscle actin), synthesis (vimentin) and senescence (p16INK4A and p21Cip1 [p16/p21]). Replicative capacity was analyzed in cultured SMCs from AS- and AR-associated aortas. A subanalysis compared SMCs from individuals with either tricuspid aortic valves or bicuspid aortic valves to evaluate the effect of aortic valve morphology.

RESULTS

In aortic tissue samples, AR was associated with decreased alpha-smooth muscle actin and increased vimentin, p16 and p21 compared with normal aortic valves and AS. In cell culture, SMCs from AR-aortas had decreased alpha-smooth muscle actin and increased vimentin compared with SMCs from AS-aortas. AR-associated SMCs had increased p16 and p21 expression, and they reached senescence earlier than SMCs from AS-aortas. In AR, SMC changes were more pronounced with the presence of a bicuspid aortic valve.

CONCLUSIONS

AR itself negatively influences SMC phenotype in the ascending aortic wall. This AR-specific effect is independent of aortic diameter and aortic valve morphology, although it is more pronounced with bicuspid aortic valves. These findings provide insight into the mechanisms of AR-related aortic remodeling, and they provide a model for studying SMC-specific therapies in culture.

Bicuspid aortic valve and its ascending aortopathy

PURPOSE OF REVIEW

To synthesize and critically assess recent clinical and research advancements in pediatric bicuspid aortic valve (BAV) and its associated aortopathy.

RECENT FINDINGS

In pediatric patients with BAV, progressive aortic dilation (i.e. bicuspid aortopathy) is commonly present and associated with increased risk for aortic aneurysm, dissection, and surgery in adulthood. Ongoing research explores the cause, incidence, and progression of bicuspid aortopathy to promote earlier diagnosis and improve preventive management. Recent findings include: high familial incidence and need for improved familial screening; safety of recreational physical activity in most affected children; potential for medical management to slow aortic growth; feasibility of pediatric registries to evaluate longitudinal outcomes; and potential genetic and hemodynamic biomarkers for disease risk stratification.

SUMMARY

Pediatric bicuspid aortopathy is an important area for investigation and preventive management to improve long-term cardiovascular outcomes. Recent literature promotes familial screening, recreational exercise, medical prophylaxis, registry-based longitudinal evaluation, and continued scientific inquiry.

The Importance of Aortic Valve Bicuspid Phenotype in Valvular Evolution in Pediatric Patients: A Case Report and Literature Mini-Review

Bicuspid aortic valve (BAV) is the most commonly encountered congenital malformation in the pediatric population, associated with aortic leaflet degeneration and aortopathy. However, studies on BAV and its complications in children are limited. We present the case of a 16-year-old with type 1B BAV with a raphe with fusion between the right and non-coronary cusps who exhibited severe aortic stenosis, regurgitation, and progressive dilatation of the ascending aorta. Surgical intervention, including aortic valve and aortic root replacement, was performed due to the patient's deteriorating condition. Histopathological examination revealed degenerative changes and calcifications in the aortic valve and mucoid fibrosis in the ascending aorta. The results are consistent with BAV patients being predisposed to aortic stenosis and regurgitation due to increased mechanical stress and hemodynamic abnormalities. Although more common in adults and a rare complication in pediatric patients, calcification was previously observed concurrently with rapid valve degeneration in our daily practice. Further studies are needed to improve our understanding of the mechanisms underlying BAV-related complications and refine treatment strategies for pediatric patients.

Mechanisms of Aortic Dilation in Patients With Bicuspid Aortic Valve: JACC State-of-the-Art Review

Bicuspid aortic valve is the most common congenital heart disease and exposes patients to an increased risk of aortic dilation and dissection. Aortic dilation is a slow, silent process, leading to a greater risk of aortic dissection. The prevention of adverse events together with optimization of the frequency of the required lifelong imaging surveillance are important for both clinicians and patients and motivated extensive research to shed light on the physiopathologic processes involved in bicuspid aortic valve aortopathy. Two main research hypotheses have been consolidated in the last decade: one supports a genetic basis for the increased prevalence of dilation, in particular for the aortic root, and the second supports the damaging impact on the aortic wall of altered flow dynamics associated with these structurally abnormal valves, particularly significant in the ascending aorta. Current opinion tends to rule out mutually excluding causative mechanisms, recognizing both as important and potentially clinically relevant.

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.

Valvular Heart Disease: New Concepts in Pathophysiology and Therapeutic Approaches

This review discusses recent advancements in the field of valvular heart disease. Topics covered include recognition of the impact of atrial fibrillation on development and assessment of valvular disease, strategies for global prevention of rheumatic heart disease, understanding and management of secondary mitral regurgitation, the updated classification of bicuspid aortic valve disease, recognition of heightened cardiovascular risk associated with moderate aortic stenosis, and a growing armamentarium of transcatheter therapies.

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.

Bicuspid Aortic Valve in Children and Adolescents: A Comprehensive Review

Bicuspid aortic valve (BAV) is the most common congenital heart defect. Prevalence of isolated BAV in the general pediatric population is about 0.8%, but it has been reported to be as high as 85% in patients with aortic coarctation. A genetic basis has been recognized, with great heterogeneity. Standard BAV terminology, recently proposed on the basis of morpho-functional assessment by transthoracic echocardiography, may be applied also to the pediatric population. Apart from neonatal stenotic BAV, progression of valve dysfunction and/or of the associated aortic dilation seems to be slow during pediatric age and complications are reported to be much rarer in comparison with adults. When required, because of severe BAV dysfunction, surgery is most often the therapeutic choice; however, the ideal initial approach to treat severe aortic stenosis in children or adolescents is not completely defined yet, and a percutaneous approach may be considered in selected cases as a palliative option in order to postpone surgery. A comprehensive and tailored evaluation is needed to define the right intervals for cardiologic evaluation, indications for sport activity and the right timing for intervention.

Outcome and Impact of Associated Left-Sided Cardiac Lesions in Coarctation of the Aorta Diagnosed During Fetal Life

Significant effort has been put into the optimization of the antenatal diagnosis of coarctation of the aorta (CoA). However, although left-sided cardiac lesions are known to cluster, the necessity to intervene postnatally for other left-sided cardiac lesions has not been reported in a cohort of fetuses with suspected CoA. We report a study of all 89 fetuses with antenatally suspected and postnatally confirmed diagnosis of CoA who underwent CoA repair as the primary procedure at a single tertiary congenital heart disease center over 10 years (January 1, 2010, to December 31, 2019). Almost 1 in 5 patients (18%) had to undergo surgery and/or transcatheter intervention on additional left-sided cardiac lesions (14%) and/or reintervention on the aortic arch (12%) during follow-up to median age of 2.85 years. Freedom from intervention at 5 years was 78% (95% confidence interval [CI] 67 to 88%) if reintervention on CoA was excluded, and 72% (95% CI 60 to 82%) if this was included. Five-year survival was 95% (95% CI 90 to 100%). Furthermore, 20% of affected infants had genetic (10%) and/or extracardiac (16%) abnormalities. Our study highlights the need for comprehensive antenatal counseling, including the prognosis of primary repair of CoA and the potential development of additional left-sided cardiac lesions, which may be difficult to diagnose prenatally even in expert hands or impossible to diagnose because of the physiology of the fetal circulation.

Hybrid Transcarotid Exclusion of Postoperative Ascending Aortic Dissection in an Infant

Aortic dissection is very rare in pediatric patients, and associated risk factors include congenital heart disease, previous cardiac surgery, and vasculopathies. Acute postoperative aortic dissection in pediatric patients can be life-threatening. We performed a novel hybrid transcarotid covered stent exclusion of a postoperative ascending aortic dissection in an infant. (Level of Difficulty: Advanced.)

Arterial Hypertension in Aortic Valve Stenosis: A Critical Update

Aortic stenosis (AS) is a very common valve disease and is associated with high mortality once it becomes symptomatic. Arterial hypertension (HT) has a high prevalence among patients with AS leading to worse left ventricle remodeling and faster degeneration of the valve. HT also interferes with the assessment of the severity of AS, leading to an underestimation of the real degree of stenosis. Treatment of HT in AS has not historically been pursued due to the fear of excess reduction in afterload without a possibility of increasing stroke volume due to the fixed aortic valve, but most recent evidence shows that several drugs are safe and effective in reducing BP in patients with HT and AS. RAAS inhibitors and beta-blockers provide benefit in selected populations based on their profile of pharmacokinetics and pharmacodynamics. Different drugs, on the other hand, have proved to be unsafe, such as calcium channel blockers, or simply not easy enough to handle to be recommended in clinical practice, such as PDE5i, MRA or sodium nitroprusside. The present review highlights all available studies on HT and AS to guide antihypertensive treatment.

Dilated ascending aorta in the fetus

INTRODUCTION

Prenatal recognition of dilated aortic root is extremely rare and there are significant challenges in counselling these patients. The primary aim of this case series is to describe the prevalence, associations and outcome of dilated ascending aorta diagnosed during fetal life.

METHODS

This is a retrospective cohort study from two tertiary fetal cardiology centres. Dilated ascending aorta was defined as gestation-specific standard deviation > 1.96 at some point during gestation.

RESULTS

Sixteen infants were live born and underwent postnatal echocardiography. Prenatally suspected bicuspid aortic valve (BAV) (n = 6) was confirmed in 5 cases (83%) postnatally. Thirteen children have been followed up for a period of minimum one year. No connective tissue disease was found.

CONCLUSIONS

Prenatal dilated ascending aorta is a rare finding (0.06%). It is associated with BAV in 37% of cases and extracardiac abnormalities in 15.7%. Nuchal translucency measurement was >3.5 in 13% of cases. Connective tissue disease was not diagnosed postnatally. This is the largest prenatal cohort with dilated ascending aorta and postnatal outcomes to date. We showed a postnatal persistence of ascending aortic dilatation in 43% of babies. In the absence of extra-cardiac abnormalities, medium term outcome appears good but postnatal surveillance of aortic dilation is required.

Surgical management of the aorta in BAV patients

Patients with a bicuspid aortic valve (BAV) frequently develop aneurysms of the aortic root and tubular ascending aorta. Aneurysms of the aortic arch, in the absence of concomitant aortopathies, are much less common. According to the 2018 American Association of Thoracic Surgery consensus guidelines on BAV-related aortopathy, prophylactic surgical aortic repair / replacement is recommended starting at a maximum aortic diameter of 50 mm in patients with risk factors. Concomitant aortic surgery is also recommended at an aortic diameter of 45 mm in those patients with other indications for cardiac surgery (most commonly aortic valve procedures). The ultimate goal of prophylactic aortic surgery is the prevention of aortic catastrophes, e.g. aortic rupture or acute aortic dissection, which are associated with high morbidity and mortality. The surgical technique used - in elective and emergency cases - depends on the involvement and nature of the aortic valve disease, as well as the extent of aortic aneurysm formation. The current review focusses on the surgical management of the aortic root, tubular ascending aorta, and proximal aortic arch in BAV patients. Despite the abovementioned recommendations, many BAV patients develop acute aortic syndromes below the recommended aortic diameter thresholds. Further research is therefore required in order to identify high-risk BAV subgroups that would benefit from earlier surgical repair.

Clinical history and management of bicuspid aortic valve in children and adolescents

Bicuspid aortic valve (BAV) is one of the most common congenital heart defects in children, adolescents and adults. BAV can occur as an isolated lesion or in association with other congenital heart defects, such as coarctation of the aorta or genetic syndromes like Turner syndrome. Although the majority of long term complications associated with BAV manifest later in life, children and adolescents may present with early onset valvular dysfunction or dilation of the aorta. BAV is a heterogeneous disease with a wide array of presentations at various ages, depending on the degree of aortic valve dysfunction, aortic dilation and presence of associated lesions. Aortic valve stenosis and/or regurgitation are the primary indications for intervention in children and adolescents with BAV. Although a majority of young patients with BAV also have some aortic dilation, interventions on the aorta are very rare during this time frame. Children and adolescents with BAV benefit from comprehensive assessment of their risk profile to determine follow-up surveillance intervals, sports recommendations, and timing of surgical intervention. The morphologic phenotype of BAV is important to identify, as it may predict future complications and prognosis.

Management of patients with combined arterial hypertension and aortic valve stenosis: a consensus document from the Council on Hypertension and Council on Valvular Heart Disease of the European Society of Cardiology, the European Association of Cardiovascular Imaging (EACVI), and the European Association of Percutaneous Cardiovascular Interventions (EAPCI)

Aortic valve stenosis (AS) is the third most common cardiovascular disease. The prevalence of both AS and arterial hypertension increases with age, and the conditions therefore often co-exist. Co-existence of AS and arterial hypertension is associated with higher global left ventricular (LV) pressure overload, more abnormal LV geometry and function, and more adverse cardiovascular outcome. Arterial hypertension may also influence grading of AS, leading to underestimation of the true AS severity. Current guidelines suggest re-assessing patients once arterial hypertension is controlled. Management of arterial hypertension in AS has historically been associated with prudence and concerns, mainly related to potential adverse consequences of drug-induced peripheral vasodilatation combined with reduced stroke volume due to the fixed LV outflow obstruction. Current evidence suggests that patients should be treated with antihypertensive drugs blocking the renin-angiotensin-aldosterone system, adding further drug classes when required, to achieve similar target blood pressure (BP) values as in hypertensive patients without AS. The introduction of transcatheter aortic valve implantation has revolutionized the management of patients with AS, but requires proper BP management during and following valve replacement. The purpose of this document is to review the recent evidence and provide practical expert advice on management of hypertension in patients with AS.