Clinical significance of the bicuspid aortic valve

Culture-Negative Endocarditis in an Immunocompromised Patient: A Case of Suspected Bartonella and Coxiella Co-Infection

We present the case of a 23-year-old man with a previous deceased-donor renal transplant maintained on tacrolimus and prednisone who developed culture-negative endocarditis (CNE) of the mitral and aortic valves. He was suspected of being co-infected with Bartonella henselae and Coxiella burnetii, confirmed with serology testing. He was successfully managed with appropriate antibiotics and dual valve replacement.

Computed Tomographic Evaluation of Congenital Left Ventricular Outflow Obstruction

Congenital left ventricular outflow obstruction represents a multilevel obstruction with several morphological forms. It can involve the subvalvular, valvar, or supravalvular portion of the aortic valve complex, and may coexist. Computed tomography (CT) plays an important supplementary role in the evaluation of patients with congenital LVOT obstruction. Unlike transthoracic echocardiography and cardiovascular magnetic resonance (CMR) imaging, it is not bounded by a small acoustic window, needs for anaesthesia or sedation, and metallic devices. Current generations of CT scanners with excellent spatial and temporal resolution, high pitch scanning, wide detector system, dose reduction algorithms, and advanced 3-dimensional postprocessing techniques provide a high-quality alternative to CMR or diagnostic cardiac catheterization. Radiologists performing CT in young children should be familiar with the advantages and disadvantages of CT and with the typical morphological imaging features of congenital left ventricular outflow obstruction.

The Hammock Sign in Computed Tomography as a Detection Aid for Bicuspid Aortic Valves

Introduction

Bicuspid aortic valve is difficult to detect on standard transverse images.

Purpose

We aimed to investigate the usefulness of the hammock sign for detection of bicuspid aortic valve.

Methods

We retrospectively investigated the usefulness of a newly proposed 'hammock sign' in a population of 45 contrast enhanced computer tomographic studies to discern tricuspid (22) from anatomical bicuspid aortic (23) valves. The gold standard of aortic morphology was the definite diagnosis in the patient's medical file, established by computed tomography, magnetic resonance, or surgery.

Results

Computer tomographic (CT) studies of each aortic morphology were randomly evaluated for the presence of the hammock sign on coronal and sagittal images, by two readers blinded to the diagnosis. Sensitivity for detecting an anatomic bicuspid valve was 86%, and specificity was 100%.

Conclusion

The hammock sign allows for a quick and easy diagnosis of an anatomical bicuspid aortic valve, merely by scrolling through the standard coronal reconstructions of any type of contrast-enhanced thoracic CT study, and regardless of any other findings associated with bicuspid aortic valve. Functional bicuspid aortic valves were not the scope of this study.

Are Thoracic Aortic Aneurysm Patients at Increased Risk for Cardiovascular Diseases?

Objectives: Abdominal aortic aneurysms are associated with a sharply increased cardiovascular risk. Cardiovascular risk management is therefore recommended in prevailing guidelines for abdominal aneurysm patients. It has been hypothesized that associated risk relates to loss of aortic compliance. If this hypothesis is correct, observations for abdominal aneurysms would also apply to thoracic aortic aneurysms. The objective of this study is to test whether thoracic aneurysms are also associated with an increased cardiovascular risk burden. Methods: Patients who underwent aortic valve or root surgery were included in the study (n = 239). Cardiovascular risk factors were studied and atherosclerosis was scored based on the preoperative coronary angiographies. Multivariate analyses were performed, controlling for cardiovascular risk factors and aortic valve morphology. Comparisons were made with the age- and gender-matched general population and non-aneurysm patients as control groups. A thoracic aortic aneurysm was defined as an aortic aneurysm of ≥45 mm. Results: Thoracic aortic aneurysm was not associated with an increased coronary atherosclerotic burden (p = 0.548). Comparison with the general population revealed a significantly higher prevalence of hypertension (61.4% vs. 32.2%, p < 0.001) and a lower prevalence of diabetes (1.4% vs. 13.1%, p = 0.001) in the thoracic aneurysm group. Conclusions: The extreme cardiovascular risk associated with abdominal aortic aneurysms is location-specific and not explained by loss of aortic compliance. Thoracic aortic aneurysm, in contrast to abdominal, is not part of the atherosclerotic disease spectrum and, therefore, cardiovascular risk management does not need to be implemented in treatment guidelines of isolated thoracic aneurysms. Hypertension should be treated.

Variability in surveillance practice for patients with diagnosis of bicuspid aortic valve syndrome

In patients with bicuspid aortic valves, guidelines call for regular follow-up to monitor disease progression and guide intervention. We aimed to evaluate how closely these recommendations are followed at a tertiary care center. Among 48,504 patients who received echocardiograms (2013-2018) at a tertiary care center, 245 patients were identified to have bicuspid aortic valve. Bivariate analyses compared characteristics between patients who did and did not receive follow-up by a cardiovascular specialist. During a median follow-up of 3.5 ± 2.2 years (mean age 55.2 ± 15.6 years, 30.2% female), 72.7% of patients had at least one visit with a cardiovascular specialist after diagnosis of bicuspid aortic valve. These patients had a higher proportion of surveillance by echocardiogram (78.7% vs. 34.3%, p < .0001), CT or MRI (41.0% vs. 3.0%, p < .0001), and were more likely to undergo surgery. Patients with moderate-severe valvular or aortic pathology were not more likely to be followed by a specialist or receive follow-up echocardiograms. Follow-up care for patients with bicuspid aortic valve was highly variable, and surveillance imaging was sparse despite guidelines. There is an urgent need for mechanisms to monitor this population with increased risk of progressive valvulopathy and aortopathy.

Cardiac Mesenchymal Stem Cell-like Cells Derived from a Young Patient with Bicuspid Aortic Valve Disease Have a Prematurely Aged Phenotype

There is significant interest in the role of stem cells in cardiac regeneration, and yet little is known about how cardiac disease progression affects native cardiac stem cells in the human heart. In this brief report, cardiac mesenchymal stem cell-like cells (CMSCLC) from the right atria of a 21-year-old female patient with a bicuspid aortic valve and aortic stenosis (referred to as biscuspid aortic valve disease BAVD-CMSCLC), were compared with those of a 78-year-old female patient undergoing coronary artery bypass surgery (referred to as coronary artery disease CAD-CMSCLC). Cells were analyzed for expression of MSC markers, ability to form CFU-Fs, metabolic activity, cell cycle kinetics, expression of NANOG and p16, and telomere length. The cardiac-derived cells expressed MSC markers and were able to form CFU-Fs, with higher rate of formation in CAD-CMSCLCs. BAVD-CMSCLCs did not display normal MSC morphology, had a much lower cell doubling rate, and were less metabolically active than CAD-CMSCLCs. Cell cycle analysis revealed a population of BAVD-CMSCLC in G2/M phase, whereas the bulk of CAD-CMSCLC were in the G0/G1 phase. BAVD-CMSCLC had lower expression of NANOG and shorter telomere lengths, but higher expression of p16 compared with the CAD-CMSCLC. In conclusion, BAVD-CMSCLC have a prematurely aged phenotype compared with CAD-CMSCLC, despite originating from a younger patient.

Surgical outcomes among children with bicuspid aortic valve: 17 years of experience in a single center. First report in Mexico

PURPOSE

To evaluate the clinical and surgical outcomes among children with bicuspid aortic valve who underwent cardiac surgery.

METHODS

This observational and retrospective study included patients with a diagnosis of bicuspid aortic valve who underwent cardiac surgery between January 1, 2003, and March 31, 2020. Demographic characteristics and perioperative conditions were described.

RESULTS

One hundred and sixteen patients were included, with a mean age of 12.4 ± 4.2 years; 63.2% were male. The most frequent diagnosis was congenital aortic stenosis (23.5%), followed by connective tissue disorders (16%). Mechanical aortic prostheses were used in 87.7% of cases, with a mean size of 21 ± 2.6 mm. The main factors associated with mortality were valve prosthesis dysfunction (odds ratio [OR]: 12.44; 95% confidence interval [CI]: 1.05-147.48; p = .04) and reoperation (OR: 24.29; 95% CI: 1.03-570.08; p = .04). The overall survival was 87.9%, with better outcomes among those who did not undergo reoperation (Log Rank, p = .01).

CONCLUSIONS

Outcomes after aortic valve replacement in children with bicuspid aortic valve are excellent in the short and long term, regardless of using mechanical or biological prostheses.

Validating In Silico and In Vitro Patient-Specific Structural and Flow Models with Transcatheter Bicuspid Aortic Valve Replacement Procedure

INTRODUCTION

Bicuspid aortic valve (BAV) is the most common congenital cardiac malformation, which had been treated off-label by transcatheter aortic valve replacement (TAVR) procedure for several years, until its recent approval by the Food and Drug Administration (FDA) and Conformité Européenne (CE) to treat BAVs. Post-TAVR complications tend to get exacerbated in BAV patients due to their inherent aortic root pathologies. Globally, due to the paucity of randomized clinical trials, clinicians still favor surgical AVR as the primary treatment option for BAV patients. While this warrants longer term studies of TAVR outcomes in BAV patient cohorts, in vitro experiments and in silico computational modeling can be used to guide the surgical community in assessing the feasibility of TAVR in BAV patients. Our goal is to combine these techniques in order to create a modeling framework for optimizing pre-procedural planning and minimize post-procedural complications.

MATERIALS AND METHODS

Patient-specific in silico models and 3D printed replicas of 3 BAV patients with different degrees of post-TAVR paravalvular leakage (PVL) were created. Patient-specific TAVR device deployment was modeled in silico and in vitro-following the clinical procedures performed in these patients. Computational fluid dynamics simulations and in vitro flow studies were performed in order to obtain the degrees of PVL in these models.

RESULTS

PVL degree and locations were consistent with the clinical data. Cross-validation comparing the stent deformation and the flow parameters between the in silico and the in vitro models demonstrated good agreement.

CONCLUSION

The current framework illustrates the potential of using simulations and 3D printed models for pre-TAVR planning and assessing post-TAVR complications in BAV patients.

The role of 4-dimensional flow in the assessment of bicuspid aortic valve and its valvulo-aortopathies

Bicuspid aortic valve is the most common congenital cardiac malformation and the leading cause of aortopathy and aortic stenosis in younger patients. Aortic wall remodelling secondary to altered haemodynamic flow patterns, changes in peak velocity, and wall shear stress may be implicated in the development of aortopathy in the presence of bicuspid aortic valve and dysfunction. Assessment of these parameters as potential predictors of disease severity and progression is thus desirable. The anatomic and functional information acquired from 4D flow MRI can allow simultaneous visualisation and quantification of the pathological geometric and haemodynamic changes of the aorta. We review the current clinical utility of haemodynamic quantities including velocity, wall sheer stress and energy losses, as well as visual descriptors such as vorticity and helicity, and flow direction in assessing the aortic valve and associated aortopathies.

Lifetime Management of Aortic Stenosis: Transcatheter Versus Surgical Treatment for Young and Low-Risk Patients

Transcatheter aortic valve replacement is now indicated across all risk categories of patients with symptomatic severe aortic stenosis and has been proposed as first line option for the majority of patients >74 years old. However, median age of patients enrolled in the transcatheter aortic valve replacement low-risk trials is 74 years and transcatheter aortic valve replacement has never been systematically investigated in young low risk patients. Although the long-term data in surgical aortic valve replacement in young patients (age <75) are well known, such data remain lacking in transcatheter aortic valve replacement. In the absence of clear guideline recommendations in patients with challenging anatomies (eg, hostile calcium, bicuspid), it is important to know the potential advantages and disadvantages of each treatment and to consider how they might integrate with each other in the lifetime management of such patients. In this review, we discuss current outstanding issues on the management of severe aortic stenosis from a lifetime management perspective, particularly in terms of initial intervention and future reinterventions.

Patients with Bicuspid Aortopathy and Aortic Dilatation

(1) Background: Bicuspid aortic valve (BAV) is the most frequent congenital cardiac disease. Alteration of ascending aorta diameter is a consequence of shear stress alterations due to haemodynamic abnormalities developed from inadequate valve cusp coaptation. (2) Objective: This narrative review aims to discuss anatomical, pathophysiological, genetical, ultrasound, and radiological aspects of BAV disease, focusing on BAV classification related to imaging patterns and flux models involved in the onset and developing vessel dilatation. (3) Methods: A comprehensive search strategy was implemented in PubMed from January to May 2022. English language articles were selected independently by two authors and screened according to the following criteria. (4) Key Contents and Findings: Ultrasound scan is the primary step in the diagnostic flowchart identifying structural and doppler patterns of the valve. Computed tomography determines aortic vessel dimensions according to the anatomo-pathology of the valve. Magnetic resonance identifies hemodynamic alterations. New classifications and surgical indications derive from these diagnostic features. Currently, indications correlate morphological results, dissection risk factors, and genetic alterations. Surgical options vary from aortic valve and aortic vessel substitution to aortic valve repair according to the morphology of the valve. In selected patients, transcatheter aortic valve replacement has an even more impact on the treatment choice. (5) Conclusions: Different imaging approaches are an essential part of BAV diagnosis. Morphological classifications influence the surgical outcome.

The Medical versus Zoological Concept of Outflow Tract Valves of the Vertebrate Heart

The anatomical elements that in humans prevent blood backflow from the aorta and pulmonary artery to the left and right ventriclesare the aortic and pulmonary valves, respectively. Each valve regularly consists of three leaflets (cusps), each supported by its valvular sinus. From the medical viewpoint, each set of three leaflets and sinuses is regarded as a morpho-functional unit. This notion also applies to birds and non-human mammals. However, the structures that prevent the return of blood to the heart in other vertebrates are notably different. This has led to discrepancies between physicians and zoologists in defining what a cardiac outflow tract valve is. The aim here is to compare the gross anatomy of the outflow tract valvular system among several groups of vertebrates in order to understand the conceptual and nomenclature controversies in the field.

Biofabrication of Sodium Alginate Hydrogel Scaffolds for Heart Valve Tissue Engineering

Every year, thousands of aortic valve replacements must take place due to valve diseases. Tissue-engineered heart valves represent promising valve substitutes with remodeling, regeneration, and growth capabilities. However, the accurate reproduction of the complex three-dimensional (3D) anatomy of the aortic valve remains a challenge for current biofabrication methods. We present a novel technique for rapid fabrication of native-like tricuspid aortic valve scaffolds made of an alginate-based hydrogel. Using this technique, a sodium alginate hydrogel formulation is injected into a mold produced using a custom-made sugar glass 3D printer. The mold is then dissolved using a custom-made dissolving module, revealing the aortic valve scaffold. To assess the reproducibility of the technique, three scaffolds were thoroughly compared. CT (computed tomography) scans showed that the scaffolds respect the complex native geometry with minimal variations. The scaffolds were then tested in a cardiac bioreactor specially designed to reproduce physiological flow and pressure (aortic and ventricular) conditions. The flow and pressure profiles were similar to the physiological ones for the three valve scaffolds, with small variabilities. These early results establish the functional repeatability of this new biofabrication method and suggest its application for rapid fabrication of ready-to-use cell-seeded sodium alginate scaffolds for heart valve tissue engineering.

The association between cardiac magnetic resonance-derived aortic stiffness parameters and aortic dilation in young adults with bicuspid aortic valve: With and without coarctation of aorta

Background

Bicuspid aortic valve (BAV) is associated with progressive aortic dilation. Studies in aortopathies have shown a correlation between increased aortic stiffness and aortic dilation. We aimed to evaluate aortic stiffness measures as predictors of progressive aortic dilation by cardiac magnetic resonance (CMR) in BAV patients.

Methods

This is a retrospective study of 49 patients with BAV (median age 21.1 years at first CMR visit) with ≥2 CMR at the Wisconsin Adult Congenital Heart Disease Program (WAtCH). Circumferential aortic strain, distensibility, and β-stiffness index were obtained from CMR-derived aortic root cine imaging, and aortic dimensions were measured at aortic root and ascending aorta. A linear mixed-model and logistic regression were used to identify important predictors of progressive aortic dilation.

Results

Over a median of 3.8 years follow-up, the annual growth rates of aortic root and ascending aorta dimensions were 0.25 and 0.16 mm/year, respectively. Aortic strain and distensibility decreased while β-stiffness index increased with age. Aortic root strain and distensibility were associated with progressive dilation of the ascending aorta. Baseline aortic root diameter was an independent predictor of >1 mm/year growth rate of the aortic root (adjusted OR 1.34, 95 % CI 1.03-1.74, p = 0.028). Most patients (61 %) had coexisting coarctation of aorta. Despite the higher prevalence of hypertension in patients with aortic coarctation, hypertension or coarctation had no effect on baseline aorta dimensions, stiffness, or progressive aortic dilation.

Conclusion

Some CMR-derived aortic stiffness parameters correlated with progressive aortic dilation in BAV and should be further investigated in larger and older BAV cohorts.

Bicuspid Aortic Valves: an Up-to-Date Review on Genetics, Natural History, and Management

PURPOSE OF REVIEW

Bicuspid aortic valve (BAV) is the most common congenital cardiac abnormality. It has a wide spectrum of clinical manifestations including aortic regurgitation (AR), aortic stenosis, and an associated aortopathy with a small but increased risk of aortic dissection. This review describes current knowledge of BAV, from anatomy and genetics to a discussion of multifaceted strategies utilized in the management of this unique patient population. This review will also highlight critical knowledge gaps in areas of basic and clinical research to enhance further understanding of this clinical entity.

RECENT FINDINGS

The current knowledge regarding pathophysiologic mechanisms, screening, and surveillance guidelines for BAV and the associated aortopathy is discussed. We also discuss current management techniques for aortic valve repair versus replacement, indications for aortic surgery (root or ascending aorta), and the emergence of the Ross procedure as a viable management option not only in children, but also in adolescents and adults. The varied clinical phenotype of the BAV, resulting in its specific complex hemodynamic interactions, renders it an entity which is separate and distinct from the tricuspid aortic valve pathologies. While various aortic histopathologic and protein alterations in BAV patients have been described, it remains unclear if these changes are causal or the result of hemodynamic alterations imposed by sheer stress on the intrinsically dysfunctional BAV. Medical management for patients with BAV with AS, AI, or dilated aortic roots/ascending aortas remains challenging and needs further investigation. More than 50% of patients with BAV will undergo AVR during their lifetime, and more than 25% of patients with BAV undergo aortic surgery performed for dilation of the aortic root or ascending aorta, often concurrently with AVR. The search for the ultimate genetic or epigenetic cause of the different bicuspid phenotypes will ultimately be facilitated by the next-generation sequencing tools that allow for study of large populations at low cost. Improvements in diagnostic and stratification criteria to accurately risk assess BAV patients are critical to this process.

Comparison of In-Hospital Outcomes and Readmission Rates of Transcatheter Aortic Valve Implantation in Mixed Aortic Valve Disease Versus Pure Aortic Stenosis

Recently, transcatheter aortic valve implantation (TAVI) has been performed in patients with combined aortic stenosis (AS) and aortic regurgitation. We sought to evaluate in-hospital outcomes and readmission rates after TAVI in patients with mixed aortic valve disease (MAVD). A total of 100,573 TAVI procedures were identified between 2011 and 2017 using International Classification of Diseases, Ninth Revision and International Classification of Diseases, Tenth Revision procedure codes the from Nationwide Readmissions Database. We separated patients into 2 cohorts, those with MAVD and those with pure AS. The primary outcome was all-cause inpatient mortality after TAVI, and secondary outcomes included rates of 30- and 90-day readmissions and postprocedural complications. A total of 3,260 patients had MAVD (median age 83 years, 43.5% women). In-hospital mortality (2.5% vs 2.6%, p = 0.531) and rates of paravalvular leak (1.0% vs 1.3%, p = 0.056) were similar between the MAVD and pure AS groups. Major bleeding (7.4% vs 9.6%, p <0.001), 30-day readmission (0.5% vs 8.8%, p <0.001) and 90-day readmission rates (0.8% vs 16.0%, p <0.001), acute kidney injury (12.9% vs 15.1%, p <0.001), postoperative ischemic stroke (2.0% vs 5.7%, p <0.001), and mechanic circulatory support use (1.9% vs 4.5%, p <0.001) were less prevalent in the MAVD cohort. Using a multivariate logistic regression model to adjust for confounding factors, MAVD was not predictive of mortality in patients who underwent TAVI (adjusted odds ratio [adjOR] 1.25, 95% confidence interval [CI] 0.99 to 1.57, p = 0.056); however, MAVD was associated with: decreased odds of 30-day readmission (adjOR 0.05, 95% CI 0.03 to 0.08, p <0.001), 90-day readmission rates (adjOR 0.04, 95% CI 0.03 to 0.06, p <0.001), and higher odds of pacemaker implantation (adjOR 1.46, 95% CI 1.29 to 1.65, p <0.001). In conclusion, despite differences in the aortic valve and left ventricular anatomy (pressure vs volume-related adaptive changes) in patients with MAVD and pure AS, TAVI appears safe and feasible. However, patients with MAVD were more likely to have permanent pacemakers implanted. The results of our study warrant further randomized controlled studies to confirm these findings.

Update on supra-annular sizing of transcatheter aortic valve prostheses in raphe-type bicuspid aortic valve disease according to the LIRA method

Recent evidence has shown that transcatheter heart valve (THV) anchoring in bicuspid aortic valve (BAV) patients occurs at the level of the raphe, known as the LIRA (Level of Implantation at the RAphe) plane. Our previous work in a cohort of 20 patients has shown that the delineation of the perimeter and device sizing at this level is associated with optimal procedural outcome. The goals of this study were to confirm the feasibility of this method, evaluate 30-day outcomes of LIRA sizing in a larger cohort of patients, assess interobserver variation and reproducibility of this sizing methodology, and analyse the interaction of LIRA-sized prostheses with the surrounding anatomy. The LIRA sizing method was applied to consecutive patients presenting to our centre with raphe-type BAV disease between November 2018 and October 2021. Supra-annular self-expanding THVs were sized based on baseline CT scan perimeters at the LIRA plane and the virtual basal ring. In cases where there was discrepancy between the two measurements, the plane with the smallest perimeter was considered the reference for prosthesis sizing. Post-procedural device success, defined according to Valve Academic Research Consortium-2 (VARC-2) criteria, was evaluated in the overall cohort. A total of 50 patients (mean age 80 ± 6 years, 70% male) with raphe-type BAV disease underwent transcatheter aortic valve replacement (TAVR) using different THV prostheses. The LIRA plane method appeared to be highly successful (100% VARC-2 device success) with no procedural mortality, no valve migration, no moderate-severe paravalvular leak, and low transprosthetic gradients (residual mean gradient 8.2 ± 3.4 mmHg). There were no strokes, no in-hospital or 30-day mortality, and an incidence of in-hospital pacemaker implantation of 10%. Furthermore, measurement of the LIRA plane perimeter was highly reproducible between observers (r = 0.980; P < 0.001) and predictive of the post-procedural prosthetic valve perimeter on CT scanning (r = 0.981; P < 0.001). We confirm the feasibility of supra-annular sizing using the LIRA method in a large cohort of patients with high procedural success and good clinical outcomes at 30 days. Application of the LIRA method optimizes THV prosthesis sizing in patients with raphe-type BAV disease.

Outcomes following use of pediatric and young adult donor hearts with bicuspid aortic valves: A single-center case series

BACKGROUND

Valvular disease in pediatric and young adult donor hearts may be a relative contraindication to graft use. Outcomes following the use of donor hearts with bicuspid aortic valve (BAV) have not been previously reported in children. We describe 4 cases of pediatric heart transplantation (HTx) utilizing a donor heart with a BAV.

CASE SERIES

Of the 469 HTx included in this study, 4 utilized a donor heart with a BAV. All recipients were female; median age was 11 years (range 0.3 to 19 years). In all cases, the BAV was not discovered until after HTx. All donors were less than 30 years old. The patients were followed for a median of 6 years (range 2 to 9 years) with all patients alive at last follow-up. Two patients have transitioned to adult care, and 2 patients continue to follow in our clinic. In follow-up, no patient has required an aortic valve intervention or had infective endocarditis. At last review, no patient had greater than mild aortic insufficiency or more than mild aortic stenosis. Three patients developed mild-to-moderate left ventricular hypertrophy in the first year post-transplant that improved over time. One patient experienced a peri-operative embolic stroke at time of transplant unrelated to the BAV.

CONCLUSION

On short- and intermediate-term follow-up, pediatric and young adult donor hearts with BAV demonstrated acceptable graft longevity and valvular function. A functionally normal BAV in a pediatric heart transplant donor should not be a contraindication to organ acceptance.

Patients With Bicuspid Aortic Stenosis Undergoing Transcatheter Aortic Valve Replacement: A Systematic Review and Meta-Analysis

Objective

We sought to conduct a systematic review and meta-analysis of clinical adverse events in patients undergoing transcatheter aortic valve replacement (TAVR) with bicuspid aortic valve (BAV) vs. tricuspid aortic valve (TAV) anatomy and the efficacy of balloon-expandable (BE) vs. self-expanding (SE) valves in the BAV population. Comparisons aforementioned will be made stratified into early- and new-generation devices. Differences of prosthetic geometry on CT between patients with BAV and TAV were presented. In addition, BAV morphological presentations in included studies were summarized.

Method

Observational studies and a randomized controlled trial of patients with BAV undergoing TAVR were included according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.

Results

A total of 43 studies were included in the final analysis. In patients undergoing TAVR, type 1 BAV was the most common phenotype and type 2 BAV accounted for the least. Significant higher risks of conversion to surgical aortic valve replacement (SAVR), the need of a second valve, a moderate or severe paravalvular leakage (PVL), device failure, acute kidney injury (AKI), and stroke were observed in patients with BAV than in patients with TAV during hospitalization. BAV had a higher risk of new permanent pacemaker implantation (PPI) both at hospitalization and a 30-day follow-up. Risk of 1-year mortality was significantly lower in patients with BAV than that with TAV [odds ratio (OR) = 0.85, 95% CI 0.75–0.97, p = 0.01]. BE transcatheter heart valves (THVs) had higher risks of annular rupture but a lower risk of the need of a second valve and a new PPI than SE THVs. Moreover, BE THV was less expanded and more elliptical in BAV than in TAV. In general, the rates of clinical adverse events were lower in new-generation THVs than in early-generation THVs in both BAV and TAV.

Conclusions

Despite higher risks of conversion to SAVR, the need of a second valve, moderate or severe PVL, device failure, AKI, stroke, and new PPI, TAVR seems to be a viable option for selected patients with severe bicuspid aortic stenosis (AS), which demonstrated a potential benefit of 1-year survival, especially among lower surgical risk population using new-generation devices. Larger randomized studies are needed to guide patient selection and verified the durable performance of THVs in the BAV population.

Feasibility of a longitudinal statistical atlas model to study aortic growth in congenital heart disease

Studying anatomical shape progression over time is of utmost importance to refine our understanding of clinically relevant processes. These include vascular remodeling, such as aortic dilation, which is particularly important in some congenital heart defects (CHD). A novel methodological framework for three-dimensional shape analysis has been applied for the first time in a CHD scenario, i.e., bicuspid aortic valve (BAV) disease, the most common CHD. Three-dimensional aortic shapes (n = 94) reconstructed from cardiovascular magnetic resonance imaging (MRI) data as surface meshes represented the input for a longitudinal atlas model, using multiple scans over time (n = 2-4 per patient). This model relies on diffeomorphism transformations in the absence of point-to-point correspondence, and on the right combination of initialization, estimation and registration parameters. We computed the shape trajectory of an average disease progression in our cohort, as well as time-dependent parameters, geometric variations and the average shape of the population. Results cover a spatiotemporal spectrum of visual and numerical information that can be further used to run clinical associations. This proof-of-concept study demonstrates the feasibility of applying advanced statistical shape models to track disease progression and stratify patients with CHD.

A Rare Case of Bicuspid Aortic Valve With Recurrent Endocarditis Complicated by an Aortic Root Pseudoaneurysm

This is a case report of a 35-year-old man who was diagnosed with a bicuspid aortic valve associated with recurrent endocarditis complicated by an aortic root pseudoaneurysm. The pseudoaneurysm is a rare complication. In patients with infective endocarditis (IE), aortic root repair by bovine pericardial patch and subsequent graft infections are considered to be one of the most common risk factors linked to postoperative aortic root pseudoaneurysms. Aneurysms can appear as saccular bulges and are often misdiagnosed as prolapse. The presentation and complicated management are discussed in this case report.

Is Bicuspid Aortic Valve Morphology Genetically Determined? A Family-Based Study

Bicuspid aortic valve (BAV) is a common congenital heart disease, with a 10-fold higher prevalence in first-degree relatives. BAV has different phenotypes based on the morphology of cusp fusion. These phenotypes are associated with different clinical courses and prognoses. Currently, the determinants of the valve phenotype are unknown. In this study we evaluated the role of genetics using familial cohorts. Patients with BAV and their first-degree relatives were evaluated by echocardiography. The concordance in BAV phenotype between pairs of family members was calculated and compared with the concordance expected by chance. We then performed a systematic literature review to identify additional reports and calculated the overall concordance rate. During the study period, 70 cases from 31 families and 327 sporadic cases were identified. BAV was diagnosed in 14% of the screened relatives. The proportions of the morphologies identified was: 12.3% for type 0, 66.2% for type 1-LR, 15.4% for type 1-RN, 4.6% for type 1-NL, and 1.5% for type 2. For the assessment of morphologic concordance, we included 120 pairs of first-degree relatives with BAV from our original cohort and the literature review. Concordance was found only in 62% of the pairs which was not significantly higher than expected by chance. In conclusion, our finding demonstrates intrafamilial variability in BAV morphology, suggesting that morphology is determined by factors other than Mendelian genetics. As prognosis differs by morphology, our findings may suggest that clinical outcomes may vary even between first-degree relatives.

Variation in management of paediatric isolated bicuspid aortic valve: current practice survey

BACKGROUND

Prior to the recent release of appropriate use criteria for imaging valvulopathies in children, follow-up of valvular lesions, including isolated bicuspid aortic valve, was not standardised. We describe current follow up, treatment, and intervention strategies for isolated bicuspid aortic valve with varying degrees of stenosis, regurgitation, and dilation in children up to 18 years old and compare them with newly released appropriate use criteria.

METHODS

Online survey was sent to members of the American Academy of Pediatrics Section on Cardiology and Cardiac Surgery and PediHeartNet.

RESULTS

Totally, 106 responses with interpretable data were received. For asymptomatic patients with isolated BAV without stenosis, regurgitation, or dilation follow-up-intervals increased from 7+/-4 months in the newborn period to 28 +/- 14 months at 18 years of age. Respondents recommended more frequent follow-up for younger patients and those with greater disease severity. More than 80% of respondents treat aortic regurgitation or aortic dilation in the setting of bicuspid aortic valve medically. In general, intervention was recommended once stenosis or regurgitation became severe (stenosis of >4 m/s; regurgitation with LV Z score 4) regardless of age, but was not routinely recommended for younger children (newborn - age 6 years) with severe dilation. Exercise was restricted at 38+/-11 mmHg echocardiographic mean gradient.

CONCLUSIONS

Current follow-up, treatment, and intervention strategies for isolated bicuspid aortic valve deviate from appropriate use criteria. Differences between the two highlight the need to better delineate the disease course, clarify recommendations for care, and encourage wider adoption of guidelines.

Cost effectiveness of screening for intracranial aneurysms among patients with bicuspid aortic valve: a Markov modelling study

OBJECTIVE

Bicuspid aortic valve (BAV) is common and 7.7%-9.8% of patients with BAV have intracranial aneuryms (IAs) which might lead to a devastating subarachnoid haemorrhage (SAH). We aimed to evaluate different screening and follow-up strategies using magnetic resonance angiography for IAs among patients with BAV.

METHODS

A decision-analytic model was built to evaluate the costs and effectiveness of different management strategies from the Chinese healthcare payer's perspective. The evaluated strategies included natural history without screening for possible IAs, regular screening and no follow-up for detected IAs, and regular screening with regular follow-up (Screen strategy/Follow-up strategy). Base case calculation, as well as probabilistic, one-way, and two-way sensitivity analyses, were performed.

RESULTS

According to the base case calculation, natural history had the least cost and effectiveness while Every 5 years (y)/Annual gained the highest cost and effectiveness. Every 10y/Biennial was cost effective when compared with Every 10y/Every 5y under the willingness-to-pay threshold of ¥211 743 (US$30 162). Probabilistic sensitivity analysis showed that Every 10y/Biennial was superior in 88.3% of the cases when compared with Every 10y/Every 5y. One-way and two-way sensitivity analyses proved that Every 10y/Biennial was the dominant strategy under most circumstances.

CONCLUSIONS

Screening for possible IAs among patients with BAV and follow-up for detected IAs would increase the effectiveness. Every 10y/Biennial was the optimal strategy from the Chinese healthcare payer's perspective.

Assessment of Paravalvular Leak Severity and Thrombogenic Potential in Transcatheter Bicuspid Aortic Valve Replacements Using Patient-Specific Computational Modeling

Bicuspid aortic valve (BAV), the most common congenital valvular abnormality, generates asymmetric flow patterns and increased stresses on the leaflets that expedite valvular calcification and structural degeneration. Recently adapted for use in BAV patients, TAVR demonstrates promising performance, but post-TAVR complications tend to get exacerbated due to BAV anatomical complexities. Utilizing patient-specific computational modeling, we address some of these complications. The degree and location of post-TAVR PVL was assessed, and the risk of flow-induced thrombogenicity was analyzed in 3 BAV patients - using older generation TAVR devices that were implanted in these patients, and compared them to the performance of the newest generation TAVR devices using in silico patient models. Significant decrease in PVL and thrombogenic potential was observed after implantation of the newest generation device. The current work demonstrates the potential of using simulations in pre-procedural planning to assess post-TAVR complications, and compare the performance of different devices to achieve better clinical outcomes. Patient-specific computational framework to assess post-transcatheter bicuspid aortic valve replacement paravalvular leakage and flow-induced thrombogenic complications and compare device performances.

Prenatal cardiac biometry and flow assessment in fetuses with bicuspid aortic valve at 20 weeks' gestation: multicenter cohort study

OBJECTIVE

To investigate prenatal changes in cardiac biometric and flow parameters in fetuses with bicuspid aortic valve (BAV) diagnosed neonatally compared with controls with normal cardiac anatomy.

METHODS

This analysis was conducted as part of the Copenhagen Baby Heart Study, a multicenter cohort study of 25 556 neonates that underwent second-trimester anomaly scan at 18 + 0 to 22 + 6 weeks' gestation and neonatal echocardiography within 4 weeks after birth, in Copenhagen University Hospital Herlev, Hvidovre Hospital and Rigshospitalet in greater Copenhagen, between April 2016 and October 2018. From February 2017 (Rigshospitalet) and September 2017 (Herlev and Hvidovre hospitals), the protocol for second-trimester screening of the heart was extended to include evaluation of the four-chamber view, with assessment of flow across the atrioventricular valves, sagittal view of the aortic arch and midumbilical artery and ductus venosus pulsatility indices. All images were evaluated by two investigators, and cardiac biometric and flow parameters were measured and compared between cases with BAV and controls. All cases with neonatal BAV were assessed by a specialist. Maternal characteristics and first- and second-trimester biomarkers were also compared between the two groups.

RESULTS

Fifty-five infants with BAV and 8316 controls with normal cardiac anatomy were identified during the study period and assessed using the extended prenatal cardiac imaging protocol. There were three times as many mothers who smoked before pregnancy in the group with BAV as in the control group (9.1% vs 2.7%; P = 0.003). All other baseline characteristics were similar between the two groups. Fetuses with BAV, compared with controls, had a significantly larger diameter of the aorta at the level of the aortic valve (3.1 mm vs 3.0 mm (mean difference, 0.12 mm (95% CI, 0.03-0.21 mm))) and the pulmonary artery at the level of the pulmonary valve (4.1 mm vs 3.9 mm (mean difference, 0.15 mm (95% CI, 0.03-0.28 mm))). Following conversion of the diameter measurements of the aorta and pulmonary artery to Z-scores and Bonferroni correction, the differences between the two groups were no longer statistically significant. Pregnancy-associated plasma protein-A (PAPP-A) multiples of the median (MoM) was significantly lower in the BAV group than in the control group (0.85 vs 1.03; P = 0.04).

CONCLUSIONS

Our findings suggest that fetuses with BAV may have a larger aortic diameter at the level of the aortic valve, measured in the left-ventricular-outflow-tract view, and a larger pulmonary artery diameter at the level of the pulmonary valve, measured in the three-vessel view, at 20 weeks' gestation. Moreover, we found an association of maternal smoking and low PAPP-A MoM with BAV. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Aortic valve endocarditis in patients with bicuspid and tricuspid aortic valves

Objective

To determine the long-term survival and rate of reoperation after surgical treatment of infective endocarditis (IE) in patients with a bicuspid aortic valve (BAV) and patients with a tricuspid aortic valve (TAV).

Methods

Between 1997 and 2017, 210 patients underwent surgical treatment for native aortic valve endocarditis, including 51 patients with BAV (24%) and 159 patients with TAV (76%). Data were obtained from the Society of Thoracic Surgeons data warehouse and hospital medical record review, supplemented with surveys and national death index data for more complete follow-up.

Results

Compared with the TAV IE group, the BAV IE group was significantly younger (42 years vs 54 years) and had lower incidence rates of hypertension, coronary artery disease, and congestive heart failure (CHF). There were no significant between-group differences in postoperative stroke, sepsis, pacemaker requirement, or in-hospital mortality (2.0% vs 4.4%). Liver disease was a risk factor for operative mortality (odds ratio [OR], 13; 95% CI, 3.3-30; P = .0002). The 10-year survival rate was 64% for the BAV group versus 46% for the TAV group (P = .0191). Significant risk factors for long-term mortality were intravenous drug use (hazard ratio [HR], 4.5; P < .0001), preoperative renal failure requiring dialysis (HR, 4.13; P < .0001), CHF (HR, 1.7; P = .04), and liver disease (HR, 2.6; P = .02). The HR for BAV was 0.67 (95% confidence interval [CI], 0.3-1.4). The 10-year postoperative cumulative incidence of reoperation was significantly higher in the BAV patients compared with the TAV patients (5.7% vs 4.5%; P = .045) with an HR of 2.4 (95% CI, 0.8-7.1; P = .11) for BAV.

Conclusions

BAV patients develop IE requiring surgery at a younger age than TAV patients, but have significantly better long-term survival. Early detection of BAV is important to prevent IE and provide aggressive surgical treatment should IE occur.

Bicuspid Aortic Valve in Pregnancy Complicated by Aortic Valve Vegetation, Aortic Root Abscess, and Aortic Insufficiency

A 39-year-old patient presented to our Labor and Delivery unit with fever and nausea in the context of recent bacteriuria. She was found to be in sepsis due to an incidental bicuspid aortic valve (BAV) complicated by aortic valvular vegetations, severe aortic insufficiency, and aortic root abscess, requiring an emergent cesarean section. Three days after delivery, the patient successfully underwent a mechanical aortic valve replacement and root reconstruction. In this case report, medical, surgical, and anesthetic management of parturient patients with BAV are discussed. The management of this congenital valvulopathy and vasculopathy is complicated by the extensive hemodynamic and cardiovascular derangements that occur during pregnancy.

Temporal Trends in Diagnosis, Treatments, and Outcomes in Patients With Bicuspid Aortic Valve

Background: The population is aging and advances in multimodal imaging and transcatheter valve intervention have been prominent in the past two decades. This study investigated temporal trends in demographic characteristics, use of multimodal imaging, treatments, and outcomes in patients with bicuspid aortic valve (BAV). Methods and Results: A total of 1,497 patients (male 71.7%, 57 ± 14 years old) first diagnosed with BAV between January 2003 and December 2020, in a single tertiary center were divided into three groups according to year of diagnosis: group 1 (2003-2008, n = 269), group 2 (2009-2014, n = 594), and group 3 (2015-2020, n = 634). The patients' demographic characteristics, comorbidities, BAV morphology, BAV function, BAV-related disease, use of multimodal diagnostic imaging, treatment modality for BAV, and clinical outcomes were compared among the three groups. The ages at diagnosis and at the time of surgery/intervention increased considerably from group 1 to 3. The patients' comorbidity index also increased progressively. The proportion of non-dysfunctional BAV and significant AS increased, while that of significant AR decreased. The frequency of infective endocarditis as an initial presentation significantly decreased over time. Additionally, the use of multimodal imaging increased markedly in the most recent group. The results also indicated increasing trends in the use of bioprosthetic valves and transcatheter aortic valve replacement. Overall and cardiovascular survival rates improved from group 1 to 3 (log rank p < 0.001). Conclusions: For the past two decades, remarkable temporal changes have occurred in patient characteristics, use of multimodal diagnostic imaging, choice of treatment modality, and clinical outcomes in patients with BAV.

The incidence and predictors of high-degree atrioventricular block in patients with bicuspid aortic valve receiving self-expandable transcatheter aortic valve implantation

BACKGROUND

The high-degree atrioventricular block (HAVB) in patients with bicuspid aortic valve (BAV) treated with transcatheter aortic valve implantation (TAVI) remains high. The study aims to explore this poorly understood subject of mechanisms and predictors for HAVB in BAV self-expandable TAVI patients.

METHODS

We retrospectively included 181 BAV patients for analysis. Using computed tomography data, the curvature of ascending aorta (AAo) was quantified by the angle (AAo angle) between annulus and the cross-section at 35 mm above annulus (where the stent interacts with AAo the most). The valvular anatomy and leaflet calcification were also characterized.

RESULTS

The 30-day HAVB rate was 16.0% (median time to HAVB was three days). Type-1 morphology was found in 79 patients (43.6%) (left- and right-coronary cusps fusion comprised 79.7%). Besides implantation below membrane septum, large AAo angle [odds ratio (OR) = 1.08, P = 0.016] and type-1 morphology (OR = 4.97, P = 0.001) were found as the independent predictors for HAVB. Together with baseline right bundle branch block, these predictors showed strong predictability for HAVB with area under the cure of 0.84 (sensitivity = 62.1%, specificity = 92.8%). Bent AAo and calcified raphe had a synergistic effect in facilitating high implantation, though the former is associated with at-risk deployment (device implanted above annulus + prothesis pop-out, versus straight AAo: 9.9% vs. 2.2%, P = 0.031).

CONCLUSIONS

AAo curvature and type-1 morphology are novel predictors for HAVB in BAV patients following self-expandable TAVI. For patients with bent AAo or calcified raphe, a progressive approach to implant the device above the lower edge of membrane septum is favored, though should be done cautiously to avoid pop-out.

Impact of calcific aortic valve disease on valve mechanics

The aortic valve is a highly dynamic structure characterized by a transvalvular flow that is unsteady, pulsatile, and characterized by episodes of forward and reverse flow patterns. Calcific aortic valve disease (CAVD) resulting in compromised valve function and increased pressure overload on the ventricle potentially leading to heart failure if untreated, is the most predominant valve disease. CAVD is a multi-factorial disease involving molecular, tissue and mechanical interactions. In this review, we aim at recapitulating the biomechanical loads on the aortic valve, summarizing the current and most recent research in the field in vitro, in-silico, and in vivo, and offering a clinical perspective on current strategies adopted to mitigate or approach CAVD.

Circulating soluble receptor of advanced glycation end product is associated with bicuspid aortic aneurysm progression via NF-κB pathway

 

OBJECTIVES

Patients with bicuspid aortic valve (BAV) have a high risk of aortic dilation and adverse vascular events. Previous studies had reported soluble receptor for advanced glycation end products (sRAGE) to compete with receptor of advanced glycation end products (RAGE) for ligand binding and inhibit the activation of nuclear-factor kappa-B (NF-κB) pathway and matrix metalloproteinases (MMP) transcription. Thus, sRAGE serum levels may contribute to the clinical diagnosis and monitoring of ascending aorta aneurysm in patients with BAV.

METHODS

To eliminate the confounding factors, 44 patients with BAV were divided into 3 subgroups according to the diameter of ascending aorta, and 20 patients with tricuspid aortic valve and normal-sized ascending aorta were selected as a control group. Protein levels and gene transcription of several variates were evaluated in the tissue and serum samples from these patients. Human aortic smooth muscle cells were treated with AGE-BSA in gradient concentrations, and changes in phenotype and protein and mRNA levels were detected.

RESULTS

Serum levels of sRAGE in the 3 BAV groups were obviously higher than those in the tricuspid aortic valve group, although there was negative correlation between the serum sRAGE levels and ascending aortic diameters among patients with BAV. Transcript expression levels of RAGE and NF-κBp65 mRNA were increased in the 3 BAV groups and RAGE/NF-κB pathway was activated with the progression of ascending aortic aneurysm. Abnormal activation of RAGE/NF-κB pathway was observed in AGE-BSA-treated human aortic smooth muscle cells.

CONCLUSIONS

Our study has shown a trend in serum levels of sRAGE among patients with BAV, and that the cellular and extracellular pathological processes are quite serious even in the normal-sized or slightly dilated aorta. Together, the findings indicated that sRAGE may be used as a biomarker to predict aneurysm expansion rates and the risk of adverse vascular events.

The selection of transcatheter heart valves in transcatheter aortic valve replacement

Transcatheter heart valve technology has rapidly progressed since initial approval in the United States. There are currently two widely available transcatheter heart valve delivery systems approved in the US; however limited data exist on optimal device selection for various patient populations. This review explores the characteristics of currently approved transcatheter heart valve systems and scenarios where one valve system may be favored over others. We provide a simplified decision tree for selecting the optimal transcatheter valve system for specific patient-centered characteristics.

Treatment of Bicuspid Aortic Valve Stenosis Using Transcatheter Heart Valves

The paucity of data regarding the use of transcatheter aortic valve replacement (TAVR) in bicuspid aortic valve (BAV) anatomy due to exclusion from pivotal studies and lack of studies assessing the long-term outcomes and valve performance continue to present a significant challenge as we expand TAVR to patients with BAV anatomy. This article discusses the important anatomic and clinical considerations in the selection and management of patients with BAV with TAVR and reviews the emerging evidence that increasingly suggests this procedure is safe, device success is excellent, and procedural outcomes are improving.

Arterial Stiffness and Left Ventricular Myocardial Function in Children with a Well-Functioning Bicuspid Aortic Valve

Fundamento:

A rigidez arterial é um importante preditor de aortopatia e remodelamento miocárdico em pacientes com válvula aórtica bicúspide, podendo estar aumentada na infância.

Objetivo:

Avaliar a rigidez arterial e a função miocárdica do ventrículo esquerdo em crianças com válvula aórtica bicúspide funcional.

Métodos:

Quarenta e quatro crianças com válvula aórtica bicúspide e 41 pares saudáveis com válvula aórtica tricúspide foram incluídos neste estudo caso-controle. Foram obtidos os diâmetros e os escores-z relacionados da raiz aórtica e da aorta ascendente. Quanto à função miocárdica do ventrículo esquerdo, juntamente com as velocidades de fluxo mitral e parâmetros do Modo M, as velocidades miocárdicas e os intervalos de tempo foram avaliados com Doppler tecidual. A análise da onda de pulso foi realizada por aparelho oscilométrico (Mobil-o-Graph). Um valor de p<0,05 foi considerado significativo.

Resultados:

O índice da massa ventricular esquerda, a velocidade A do fluxo mitral, o diâmetro e o escore z da aorta ascendente e o índice de desempenho miocárdico estavam significativamente maiores nos pacientes (p = 0,04, p = 0,02, p = 0,04, p <0,001 e p <0,001 respectivamente). O índice de desempenho miocárdico correlacionou-se positivamente com o diâmetro da aorta ascendente e a velocidade A (r=0,272; p=0,01, r=356; p=0,001, respectivamente). A análise multivariada revelou que o índice de desempenho miocárdico estava relacionado ao diâmetro da aorta ascendente (p = 0,01). O índice de aumento e a velocidade da onda de pulso foram semelhantes entre os grupos (p> 0,05).

Conclusão:

De acordo com a análise da onda de pulso oscilométrico, as crianças com válvula aórtica bicúspide funcional apresentam rigidez arterial semelhante a seus pares saudáveis. O diâmetro da aorta ascendente foi estabelecido como preditor independente da função miocárdica do ventrículo esquerdo. A rigidez arterial pode não ser um fator de risco grave em pacientes pediátricos sem dilatação acentuada da aorta ascendente.

Comparative evaluation of coronary disease burden: bicuspid valve disease is not atheroprotective

OBJECTIVE

Bicuspid aortic valve (BAV) has been associated with less atherosclerosis as compared with tricuspid aortic valve (TAV) patients. It, however, remains unclear whether this reflects the older age of TAV patients and/or accumulation of atherosclerotic risk factors or that the BAV phenotype is atheroprotective. Therefore, we compared the atherosclerotic disease burden of BAV and TAV patients, with that of the general (age-matched) population.

METHODS

The prevalence of coronary artery disease (CAD) and CAD risk factors in BAV and TAV patients who underwent aortic valve surgery were compared with the Dutch general practitioners registry data. BAV (n=454) and TAV (n=1101) patients were divided into four groups: BAV with aortic valve stenosis (BAV-AoS), BAV with aortic valve regurgitation (BAV-AR), TAV with AoS (TAV-AoS) and TAV with AR (TAV-AR). The atherosclerotic disease burden of each group was compared with that of the corresponding age cohort for the general population.

RESULTS

CAD risk factors hypertension and hypercholesterolaemia were more prevalent in the surgery groups than the age-matched general population (all p<0.001). All BAVs (BAV-AoS and BAV-AR) and TAV-AR had a similar incidence of CAD history as compared to the age-matched general populations (p=0.689, p=0.325 and p=0.617 respectively), whereas TAV-AoS had a higher incidence (21.6% versus 14.9% in the age-matched general population, p<0.001).

CONCLUSIONS

Stenotic TAV disease is part of the atherosclerotic disease spectrum, while regurgitant TAV and all BAVs are not. Although the prevalence of cardiovascular risk factors is higher in all BAV patients, the prevalence of CAD is similar to the general population.

Characteristics of Bicuspid Aortic Valve Disease and Stenosis: The National Echo Database of Australia

Background

Bicuspid aortic valve (BAV) is the most common congenital heart disease in adults but is clinically heterogeneous. We aimed to describe the echocardiographic characteristics of BAV and compare patients with BAV with moderate‐to‐severe aortic stenosis (AS) with those with tricuspid aortic valve (TAV) stenosis.

Methods and Results

Using the National Echo Database of Australia, patients in whom BAV was identified were studied. Those with moderate‐to‐severe AS (mean gradient >20 mm Hg [BAV‐AS]) were compared with those with TAV and moderate‐to‐severe AS (TAV‐AS). Of 264 159 adults whose aortic valve morphology was specified, 4783 (1.8%) had confirmed BAV (aged 49.6±17.4 years, 69% men). Of these, 42% had no AS, and 46% had no aortic regurgitation. Moderate‐to‐severe AS was detected in a greater proportion of patients with BAV with a recorded mean gradient (n=1112, 34%) compared with those with TAV (n=4377, 4%; P<0.001). Patients with BAV‐AS were younger (aged 55.3±16.7 years versus 77.3±11.0 years; P<0.001), and where measured had larger ascending aortic diameters (37±8 mm versus 35±5 mm; P<0.001). Age and sex‐adjusted mortality risk was significantly lower in patients with BAV‐AS (hazard ratio, 0.53; 95% CI, 0.45–0.63; P<0.001).

Conclusions

In this large study of patients across the spectrum of BAV disease, the largest proportion had no significant valvulopathy or aortopathy. Compared with those with TAV‐AS, patients with BAV were more likely to have moderate‐to‐severe AS, have larger ascending aortas, and were over 2 decades younger at the time of AS diagnosis. Despite this, patients with BAV appear to have a more favorable prognosis when AS develops, compared with those with TAV‐AS.

Registration

URL: www.anzctr.org.au/; Unique identifier: ACTRN12617001387314.

Aortic root aortopathy in bicuspid aortic valve associated with high genetic risk

Background

The bicuspid aortic valve (BAV) is prone to ascending aortic dilatation (AAD) involving both the tubular segment and the aortic root. The genetic factor was proposed as one of the most important mechanisms for AAD. We hypothesized that the rare genetic variants mainly contribute to the pathogenesis of aortic roots in affected individuals.

Methods

The diameter of aortic root or ascending aorta ≥ 40 mm was counted as AAD. The targeted next-generation sequencing of 13 BAV-associated genes were performed on a continuous cohort of 96 unrelated BAV patients. The rare variants with allele frequency < 0.05% were selected and analyzed. Variants frequency was compared against the Exome aggregation consortium database. The pathogenicity of the genetic variants was evaluated according to the American College of Medical Genetics and Genomics guidelines.

Results

A total of 27 rare nonsynonymous coding variants involving 9 genes were identified in 25 individuals. The burden analysis revealed that variants in GATA5, GATA6, and NOTCH1 were significantly associated with BAV. Eighty percent of the pathogenic variants were detected in root group. The detection rate of rare variants was higher in root dilatation group (71.4%) compared with normal aorta (29.0%) and tubular dilatation groups (29.6%) (P = 0.018). The rare variant was identified as the independent risk factor of root dilatation [P = 0.014, hazard ratio = 23.9, 95% confidence interval (1.9–302.9)].

Conclusions

Our results presented a broad genetic spectrum in BAV patients. The rare variants of BAV genes contribute the most to the root phenotype among BAV patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02215-y.

A Multi-Omics Approach Using a Mouse Model of Cardiac Malformations for Prioritization of Human Congenital Heart Disease Contributing Genes

Congenital heart disease (CHD) is the most common type of birth defect, affecting ~1% of all live births. Malformations of the cardiac outflow tract (OFT) account for ~30% of all CHD and include a range of CHDs from bicuspid aortic valve (BAV) to tetralogy of Fallot (TOF). We hypothesized that transcriptomic profiling of a mouse model of CHD would highlight disease-contributing genes implicated in congenital cardiac malformations in humans. To test this hypothesis, we utilized global transcriptional profiling differences from a mouse model of OFT malformations to prioritize damaging, de novo variants identified from exome sequencing datasets from published cohorts of CHD patients. Notch1 +/- ; Nos3 -/- mice display a spectrum of cardiac OFT malformations ranging from BAV, semilunar valve (SLV) stenosis to TOF. Global transcriptional profiling of the E13.5 Notch1 +/- ; Nos3 -/- mutant mouse OFTs and wildtype controls was performed by RNA sequencing (RNA-Seq). Analysis of the RNA-Seq dataset demonstrated genes belonging to the Hif1α, Tgf-β, Hippo, and Wnt signaling pathways were differentially expressed in the mutant OFT. Mouse to human comparative analysis was then performed to determine if patients with TOF and SLV stenosis display an increased burden of damaging, genetic variants in gene homologs that were dysregulated in Notch1 +/- ; Nos3 -/- OFT. We found an enrichment of de novo variants in the TOF population among the 1,352 significantly differentially expressed genes in Notch1 +/- ; Nos3 -/- mouse OFT but not the SLV population. This association was not significant when comparing only highly expressed genes in the murine OFT to de novo variants in the TOF population. These results suggest that transcriptomic datasets generated from the appropriate temporal, anatomic and cellular tissues from murine models of CHD may provide a novel approach for the prioritization of disease-contributing genes in patients with CHD.

MicroRNAs involve in bicuspid aortic aneurysm: pathogenesis and biomarkers

The incidence of bicuspid aortic valves (BAV) is high in the whole population, BAV-related thoracic aortic aneurysm (TAA) is accompanied by many adverse vascular events. So far, there are two key points in dealing with BAV-related TAA. First is fully understanding on its pathogenesis. Second is optimizing surgical intervention time. This review aims to illustrate the potential role of miRNAs in both aspects, that is, how miRNAs are involved in the occurrence and progression of BAV-related TAA, and the feasibilities of miRNAs as biomarkers.

Commissural repositioning in bicuspid aortic valve repair: an in vitro acute model to explore and explain different results

OBJECTIVES

Commissural orientation <160° is a recognized risk factor for bicuspid aortic valve repair failure. Based on this observation, repairing this subtype of aortic valve by reorienting the 2 commissures at 180° has recently been proposed.

METHODS

Nine porcine hearts with aortic annulus diameters of 25 mm were selected. A pathological model of a Sievers 1 bicuspid aortic valve was obtained by suturing the coaptation line between the left and right leaflets. Each heart underwent reimplantation procedures both in the native (120°) and the reoriented (180°) configuration. After the operation, each sample was tested on a pulse duplicator at rest (heart rate 60 beats per min) and with mild exercise (heart rate 90 beats per min) conditions.

RESULTS

No statistically significant difference was noted in mean and peak transvalvular aortic gradients between the 2 configurations at rest (18.6 ± 5 vs 17.5 ± 4 for the mean aortic gradient; 42.8 ± 12.7 vs 36.3 ± 5.8 for the peak aortic gradient) but the group with the 120°-oriented commissures had significantly higher mean transaortic gradients compared to the group with the 180°-oriented commissures at initial exercise stress conditions (30.1 ± 9.1 vs 24.9 ± 3.8; p value 0.002).

CONCLUSIONS

The 180° commissural reorientation of the asymmetrical bicuspid aortic valve does not improve the transvalvular aortic gradient in an acute model at rest conditions, but it could do so under stress situations. Even if it is surgically more complex and time-consuming, this approach could be a good strategy to improve long-term results, particularly in young patients.

Significance of Hemodynamics Biomarkers, Tissue Biomechanics and Numerical Simulations in the Pathogenesis of Ascending Thoracic Aortic Aneurysms

Guidelines for the treatment of aortic wall diseases are based on measurements of maximum aortic diameter. However, aortic rupture or dissections do occur for small aortic diameters. Growing scientific evidence underlines the importance of biomechanics and hemodynamics in aortic disease development and progression. Wall shear stress (WWS) is an important hemodynamics marker that depends on aortic wall morphology and on the aortic valve function. WSS could be helpful to interpret aortic wall remodeling and define personalized risk criteria. The complementarity of Computational Fluid Dynamics and 4D Magnetic Resonance Imaging as tools for WSS assessment is a promising reality. The potentiality of these innovative technologies will provide maps or atlases of hemodynamics biomarkers to predict aortic tissue dysfunction. Ongoing efforts should focus on the correlation between these non-invasive imaging biomarkers and clinico-pathologic situations for the implementation of personalized medicine in current clinical practice.

Bicuspid Aortic Valve: Genetic and Clinical Insights

Bicuspid aortic valve (BAV) is the most common valvular congenital heart disease, with a prevalence of 0.5 to 2% in the general population. Patients with BAV are at risk for developing cardiovascular complications, some of which are life-threatening. BAV has a wide spectrum of clinical presentations, ranging from silent malformation to severe and even fatal cardiac events. Despite the significant burden on both the patients and the health systems, data are limited regarding pathophysiology, risk factors, and genetics. Family studies indicate that BAV is highly heritable, with autosomal dominant inheritance, incomplete penetrance, variable expressivity, and male predominance. Owing to its complex genetic model, including high genetic heterogenicity, only a few genes were identified in association with BAV, while the majority of BAV genetics remains obscure. Here, we review the different forms of BAV and the current data regarding its genetics. Given the clear heritably of BAV with the potential high impact on clinical outcome, the clinical value and cost effectiveness of cascade screening are discussed.

Urinary Metabolomics Study of Patients with Bicuspid Aortic Valve Disease

Bicuspid aortic valve (BAV) is the most common congenital heart defect responsible for valvular and aortic complications in affected patients. Causes and mechanisms of this pathology are still elusive and thus the lack of early detection biomarkers leads to challenges in its diagnosis and prevention of associated cardiovascular anomalies. The aim of this study was to explore the potential use of urine Nuclear Magnetic Resonance (NMR) metabolomics to evaluate a molecular fingerprint of BAV. Both multivariate and univariate statistical analyses were performed to compare the urinary metabolome of 20 patients with BAV with that of 24 matched controls. Orthogonal partial least squared discriminant analysis (OPLS-DA) showed statistically significant discrimination between cases and controls, suggesting seven metabolites (3-hydroxybutyrate, alanine, betaine, creatine, glycine, hippurate, and taurine) as potential biomarkers. Among these, glycine, hippurate and taurine individually displayed medium sensitivity and specificity by receiver operating characteristic (ROC) analysis. Pathway analysis indicated two metabolic pathways likely perturbed in BAV subjects. Possible contributions of gut microbiota activity and energy imbalance are also discussed. These results constitute encouraging preliminary findings in favor of the use of urine-based metabolomics for early diagnosis of BAV.

Cost-effectiveness analysis of screening for first-degree relatives of patients with bicuspid aortic valve

AIMS

Bicuspid aortic valve (BAV) is the commonest congenital heart valve malformation, and is associated with life-threatening complications. Given the high heritability index of BAV, many experts recommend echocardiography screening for first-degree relatives (FDRs) of an index case. Here we aim to evaluate the cost-effectiveness of such cascade screening for BAV.

METHODS

Using a decision-analytic model, we performed a cost-effectiveness analysis of echocardiographic screening for FDRs of BAV index case. Data on BAV probabilities and complications among FDRs were derived from our institution's BAV familial cohort and from the literature on population-based BAV cohorts with long-term follow-up. Health gain was measured as quality-adjusted life years (QALYs). Cost inputs were based on list prices and literature data. One-way and probabilistic sensitivity analyses were performed to account for uncertainty in the model's variables.

RESULTS

Screening of FDRs was found to be the dominant strategy, being more effective and less costly than no screening, with savings of €644 and gains of 0.3 QALYs. Results were sensitive throughout the rang of the model's variables, including the full range of reported BAV rates among FDRs across the literature. A gradual decrease of the incremental effect was found with the increase in screening age.

CONCLUSIONS

This economic evaluation model found that echocardiographic screening of FDRs of BAV index case is not only clinically important but also cost-effective and cost-saving. Sensitivity analysis supported the model's robustness, suggesting its generalization.