Coronary anatomy in children with bicuspid aortic valves and associated congenital heart disease

Coronary anomalies associated with ventricular septal defect

Coronary anomalies encompass different conditions in terms of anomalous origin, coursing, and branching, which are occasionally associated with congenital heart disease. This study aimed to explore coronary anomalies associated with ventricular septal defect that was a stereotypical congenital heart disease. We retrospectively reviewed angiographic findings in patients with ventricular septal defect who required corrective surgery, and identified coronary abnormalities, including anomalous origin, coursing, and branching of coronary arteries based on angiography. We studied the prevalence and types of coronary anomalies among them. A total of 998 patients with ventricular septal defect was studied. Age and weight were 2.0 (2.1-15.2) months and 5.7 (4.1-8.7) kg, respectively. There were 115 patients (12%) with syndrome or genetic disorder, and 34 patients (3%) with extracardiac major organ anomalies. The overall prevalence of coronary anomalies was 6.2%. All coronary anomalies were anomalous origin and coursing, among 3 patients accompanied anomalous intrinsic coronary anatomy. Originating within aortic root above the Valsalva sinus was the most common coronary anomaly. Coronary anomalies were independently correlated with bicuspid aortic valve (odds ratio [OR]: 8.02, 95% confidence interval [CI]: 2.34-23.4) and persistent left superior caval vein (OR: 5.02, 95% CI: 1.93-11.7). We showed the possibility that minor cardiac variants, such as bicuspid aortic valve and persistent left superior caval vein, contribute to higher prevalence of coronary anomalies in patients with ventricular septal defect.

Coronary Artery Origins Pattern in Pediatric Patients with Right-Left Fusion Bicuspid Aortic Valve

Bicuspid aortic valve (BAV) is a common congenital heart defect associated with coronary artery (CA) variants, including higher incidence of left CA dominance and shorter left main CA length. We observed by transthoracic echocardiography that left and right CA origins appear closer together in pediatric patients with right-left fusion (R/L) BAV compared to patients with trileaflet aortic valves. We sought to objectively confirm this observation. A retrospective review of pediatric echocardiograms with R/L BAV at a single institution (12/2010-11/2018) was performed. The 'coronary angle' was defined as the angle between the left and right coronary artery origins in the parasternal short axis view relative to the center of the aortic valve orifice. Values were compared to age-matched controls. Patients with inadequate images, anomalous coronary origins, or predefined significant congenital heart defects were excluded. We compared 191 R/L BAV patients (64% male) to 136 controls (57% male). Coronary angle was significantly more acute in R/L BAV than in controls (117.9° ± 16.7° vs 139.0° ± 10.1°, p < 0.0001). This was independent of age and gender. The difference persisted when BAV patients with abnormal aortic annulus/root diameters were removed from analysis (119.5° ± 15.1° vs 139.0° ± 10.1°, p < 0.0001). CA origins are closer together in R/L BAV independent of age, gender, or annulus/root size. This new anatomical description may aid in the diagnosis of subtle ('forme fruste') R/L BAV, assist in interventional planning, and improve understanding of the relationship between BAV and CA development.

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.

A SOX17-PDGFB signaling axis regulates aortic root development

Developmental etiologies causing complex congenital aortic root abnormalities are unknown. Here we show that deletion of Sox17 in aortic root endothelium in mice causes underdeveloped aortic root leading to a bicuspid aortic valve due to the absence of non-coronary leaflet and mispositioned left coronary ostium. The respective defects are associated with reduced proliferation of non-coronary leaflet mesenchyme and aortic root smooth muscle derived from the second heart field cardiomyocytes. Mechanistically, SOX17 occupies a Pdgfb transcriptional enhancer to promote its transcription and Sox17 deletion inhibits the endothelial Pdgfb transcription and PDGFB growth signaling to the non-coronary leaflet mesenchyme. Restoration of PDGFB in aortic root endothelium rescues the non-coronary leaflet and left coronary ostium defects in Sox17 nulls. These data support a SOX17-PDGFB axis underlying aortic root development that is critical for aortic valve and coronary ostium patterning, thereby informing a potential shared disease mechanism for concurrent anomalous aortic valve and coronary arteries.

Transposition With Unobstructed Right Aortic Arch and Bicuspid Aortic Valve

In patients with transposition, a right aortic arch has rarely been reported among the associated malformations. When present, the arch has been obstructed because of the presence of aortic coarctation and/or arch hypoplasia. A bicuspid aortic valve is also very rare in the presence of transposition. We report here the unusual association of transposition, an unobstructed right aortic arch, and a bicuspid aortic valve in a neonate who underwent a successful arterial switch operation.

Clinical and pathophysiological aspects of bicuspid aortic valve disease

A bicuspid aortic valve is not only a common congenital heart defect but also an enigmatic condition that can cause a large spectrum of diseases, such as aortic valve stenosis and severe heart failure in newborns whereas aortic dissection in adults. On the contrary, a bicuspid aortic valve can also occur with normal function throughout life and never need treatment. Numerous genetic mechanisms are involved in the abnormal cellular functions that may cause abnormal development of the aortic valve during early foetal life. As several chromosomal disorders are also associated with a bicuspid valve, there does not appear to be an apparent common trigger to the abnormal development of the aortic valve. The clinical care of the bicuspid aortic valve patient has been changed by a significant body of evidence that has improved the understanding of the natural history of the disease, including when to best intervene with valve replacement and when to provide prophylactic aortic root surgery. Moreover, as bicuspid valve disease is also part of various syndromes, we can identify high-risk patients in whom a bicuspid valve is much more unfavourable than in the normal population. This review provides an overview of all aspects of the bicuspid aortic valve condition and gives an updated perspective on issues from pathophysiology to clinical care of bicuspid aortic valve disease and associated aortic disease in asymptomatic, symptomatic, and pregnant patients, as well as our viewpoint on population screening.

Pulmonary Valve Morphology in Patients with Bicuspid Aortic Valves

The aortic and pulmonary valve share a common developmental origin from the embryonic arterial trunk. Bicuspid aortic valve is the most common congenital anomaly and can occur isolated as well as in association with other congenital heart disease (CHD). Data on pulmonary valve morphology in these cases are scarce. In this study, we aimed to determine pulmonary valve morphology in hearts with BAV associated with CHD. In 83 post-mortem heart specimens with BAV and associated CHD, pulmonary valve morphology was studied and related to BAV morphology. In 14/83 (17%) hearts, the pulmonary valve was affected, bicuspid in 8/83 (10%), dome-shaped in 3/83 (4%) and atretic in 3/83 (4%). In specimens with a bicuspid pulmonary valve, 5/8 (63%) had a strictly bicuspid aortic valve (without raphe), 2/3 hearts (67%) with dome-shaped pulmonary valves and 2/3 hearts (67%) with atretic pulmonary valves had BAV without raphe. Six out of eight (75%) specimens with a bicuspid pulmonary valve had a perimembranous ventricular septal defect (VSD). 4/8 (50%) specimens with a bicuspid pulmonary valve were associated with chromosomal abnormalities: 3 (38%) had trisomy 18 and 1 (13%) had trisomy 13. In BAV with associated CHD, abnormal pulmonary valve morphology was observed in 17% of the hearts. The majority of hearts with abnormal pulmonary valve morphology had a Type B bicuspid aortic valve (without raphe). Bilateral semilunar valvular disease is associated with Type B BAVs and in many cases related to chromosomal abnormalities. As this study was performed in post-mortem specimens with high frequency of associated CHD, caution is warranted with application of these results to the general BAV population.