Population-based treated prevalence, risk factors, and outcomes of bicuspid aortic valve in a pediatric Medicaid cohort

Whole Exome Sequencing Uncovers the Genetic Complexity of Bicuspid Aortic Valve in Families with Early Onset Complications

Bicuspid Aortic Valve (BAV) is the most common adult congenital heart lesion with an estimated population prevalence of 1%. We hypothesize that early onset complications of BAV (EBAV) are driven by specific impactful genetic variants. We analyzed whole exome sequences (WES) to identify rare coding variants that contribute to BAV disease in 215 EBAV families. Predicted pathogenic variants of causal genes were present in 111 EBAV families (51% of total), including genes that cause BAV (8%) or heritable thoracic aortic disease (HTAD, 17%). After appropriate filtration, we also identified 93 variants in 26 novel genes that are associated with autosomal dominant congenital heart phenotypes, including recurrent deleterious variation of FBN2, MYH6, channelopathy genes, and type 1 and 5 collagen genes. These findings confirm our hypothesis that unique rare genetic variants contribute to early onset complications of BAV disease.

Calcific aortic valve disease: mechanisms, prevention and treatment

Calcific aortic valve disease (CAVD) is the most common disorder affecting heart valves and is characterized by thickening, fibrosis and mineralization of the aortic valve leaflets. Analyses of surgically explanted aortic valve leaflets have shown that dystrophic mineralization and osteogenic transition of valve interstitial cells co-occur with neovascularization, microhaemorrhage and abnormal production of extracellular matrix. Age and congenital bicuspid aortic valve morphology are important and unalterable risk factors for CAVD, whereas additional risk is conferred by elevated blood pressure and plasma lipoprotein(a) levels and the presence of obesity and diabetes mellitus, which are modifiable factors. Genetic and molecular studies have identified that the NOTCH, WNT-β-catenin and myocardin signalling pathways are involved in the control and commitment of valvular cells to a fibrocalcific lineage. Complex interactions between valve endothelial and interstitial cells and immune cells promote the remodelling of aortic valve leaflets and the development of CAVD. Although no medical therapy is effective for reducing or preventing the progression of CAVD, studies have started to identify actionable targets.

Concomitant cardiovascular malformations in isolated bicuspid aortic valve disease: a retrospective cross-sectional study and meta-analysis

Background

Congenital bicuspid aortic valve affects up to 2% of the general population. It occurs in complex congenital heart defects or in syndromes such as Turner, Marfan, or Loeys-Dietz. However, the majority of bicuspid aortic valves are considered to manifest as isolated malformations.

Methods

We aimed to assess retrospectively associated cardiovascular malformations in 200 individuals with bicuspid aortic valve considered to occur as an isolated manifestation. All individuals underwent transthoracic echocardiography, 164 thoracoabdominal tomographic imaging, and 84 coronary artery imaging. In addition, we also performed a meta-analysis of data from the literature to assess the occurrence of associate malformations.

Results

In our retrospective cross-sectional study collective, the mean age was 45±15 years, 154 (77%) individuals were male. Anatomy of bicuspid aortic valve according to Schaefer was type 1 in 142 (71%), type 2 in 35 (18%), type 3 in 2 (1%), unicuspid in 6 (3%), and unclassified in 15 (8%) individuals. Coarctation of the aorta had 4.2% of individuals, 3.6% had coronary anomalies. No individual had a patent ductus arteriosus, 0.5% had atrial and ventricular septal defect each, 1.5% mitral valve prolapse. No individual had a tricuspid valve prolapse. Our meta-analysis identified in cohorts with isolated bicuspid aortic valve 11.8% (95% CI: 7.7–16.0%) individuals with aortic coarctation, 3.7% (95% CI: 1.2–6.1%) with coronary anomalies, 3.3% (95% CI: 0.0–6.7%) with patent ductus arteriosus, 5.9% (95% CI: 1.3–10.5%) with ventricular septal defect and 1.6% (95% CI: 1.1–2.1%) with mitral valve prolapse.

Conclusions

Individuals with isolated bicuspid aortic valve may exhibit a variety of associated cardiovascular malformations and therefore screening for associated malformations may be warranted.

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.

Aortic valve surgery: management and outcomes in the paediatric population

Congenital anomalies of the aortic valve frequently necessitate intervention in childhood. The most common aortic valve pathologies present in childhood are aortic stenosis and insufficiency. Presentation of aortic valve disease depends on severity and presence of concomitant syndromes and valvular disorders. Treatment options are largely categorised as medical, percutaneous repair or surgical repair and replacement. Surgical techniques have been refined over the last few years making this the mainstay of treatment in paediatric cases. Whilst repair is considered in most instances before replacement, there are substantial limitations which are reflected in the frequency of reintervention and restenosis rate. Replacements are typically undertaken with tissue or mechanical prosthesis. The current gold-standard aortic valve replacement surgery is called the Ross procedure-where replacement is undertaken with a competent pulmonic valve and a simultaneous pulmonary homograft.Conclusion: In this review, we aim to outline the various surgical options and discuss efficacy and complications of various interventions. What is Known: • Congenital aortic valve defects repair options medically and surgically What is New: • Comparisons between surgical options for aortic valve repair including efficacy, risks and long-term outcomes.

Comprehensive MR Analysis of Cardiac Function, Aortic Hemodynamics and Left Ventricular Strain in Pediatric Cohort with Isolated Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) disease demonstrates a range of clinical presentations and complications. We aim to use cardiac MRI (CMR) to evaluate left ventricular (LV) parameters, myocardial strain and aortic hemodynamics in pediatric BAV patients with and without aortic stenosis (AS) or regurgitation (AR) compared to tricuspid aortic valve (TAV) controls. We identified 58 pediatric BAV patients without additional cardiovascular pathology and 25 healthy TAV controls (15.3 ± 2.2 years) who underwent CMR with 4D flow. BAV cohort included subgroups with no valvulopathy (n = 13, 14.3 ± 4.7 years), isolated AS (n = 19, 14.5 ± 4.0 years), mixed valve disease (AS + AR) (n = 13, 17.1 ± 3.2 years), and prior valvotomy/valvuloplasty (n = 13, 13.9 ± 3.2 years). CMR data included LV volumetric and mass indices, myocardial strain and aortic hemodynamics. BAV patients with no valvulopathy or isolated AS had similar LV parameters to controls excepting cardiac output (p < 0.05). AS + AR and post-surgical patients had abnormal LV volumetric and mass indices (p < 0.01). Post-surgical patients had decreased global longitudinal strain (p = 0.02); other subgroups had comparable strain to controls. Patients with valvulopathy demonstrated elevated velocity and wall shear stress (WSS) in the ascending aorta (AAo) and arch (p < 0.01), while those without valve dysfunction had only elevated AAo velocity (p = 0.03). Across the cohort, elevated AAo velocity and WSS correlated to higher LV mass (p < 0.01), and abnormal hemodynamics correlated to decreased strain rates (p < 0.045). Pediatric BAV patients demonstrate abnormalities in LV parameters as a function of valvular dysfunction, most significantly in children with AS + AR or prior valvotomy/valvuloplasty. Correlations between aortic hemodynamics, LV mass and strain suggest valvular dysfunction could drive LV remodeling. Multiparametric CMR assessment in pediatric BAV may help stratify risk for cardiac remodeling and dysfunction.