The extent of the raphe in bicuspid aortic valves is associated with aortic regurgitation and aortic root dilatation

The role of transforming growth factor beta in bicuspid aortic valve aortopathy

A bicuspid aortic valve (BAV) is the most prevalent congenital cardiac deformity, which is associated with an increased risk to develop a thoracic aortic aneurysm and/or an aortic dissection as compared to persons with a tricuspid aortic valve. Due to the high prevalence of a BAV in the general population and the associated life-long increased risk for adverse vascular events, BAV disease places a considerable burden on the public health. The aim of the present review is to discuss the role of transforming growth factor beta (TGF-β) signaling in the development of the vascular wall and on how this complex signaling pathway may be involved in thoracic aortic aneurysm formation in tricuspid and BAV patients.

Aortic Valve Dysfunction and Aortopathy Based on the Presence of Raphe in Patients with Bicuspid Aortic Valve Disease

(1) Background: To identify the association between the presence or absence of a raphe and aortic valve dysfunction, as well as the presence of aortopathy in patients with a bicuspid aortic valve (BAV); (2) Methods: This retrospective study enrolled 312 participants (mean (SD) age, 52.7 (14.3) years; 227 men (72.8%)) with BAV. The BAVs were divided into those with the presence (raphe+) or absence (raphe-) of a raphe. Valvular function was classified as normal, aortic regurgitation (AR), or aortic stenosis (AS) using TTE. The pattern of BAV aortopathy was determined by the presence of dilatation at the sinus of Valsalva and the middle ascending aorta using CCT; (3) Results: BAVs with raphe+ had a higher prevalence of AR (148 (79.5%) vs. 48 (37.8%), p < 0.001), but a lower prevalence of AS (90 (48.6%) vs. 99 (78.0%), p < 0.001) compared with those with raphe-. The types of BAV aortopathy were significantly different (p = 0.021) according to those with BAV-raphe+ and BAV-raphe-; (4) Conclusions: The presence of a raphe was significantly associated with a higher prevalence of AR, but a lower prevalence of AS and combined dilatation of the aortic root and middle ascending aorta. The presence of a raphe was an independent determinant of AR.

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.

Influence of aortic valve morphology on vortical structures and wall shear stress

The aim of this paper is to assess the association between valve morphology and vortical structures quantitatively and to highlight the influence of valve morphology/orientation on aorta's susceptibility to shear stress, both proximal and distal. Four-dimensional phase-contrast magnetic resonance imaging (4D PCMRI) data of 6 subjects, 3 with tricuspid aortic valve (TAV) and 3 with functionally bicuspid aortic values (BAV) with right-left coronary leaflet fusion, were processed and analyzed for vorticity and wall shear stress trends. Computational fluid dynamics (CFD) has been used with moving TAV and BAV valve designs in patient-specific aortae to compare with in vivo shear stress data. Vorticity from 4D PCMRI data about the aortic centerline demonstrated that TAVs had a higher number of vortical flow structures than BAVs at peak systole. Coalescing of flow structures was shown to be possible in the arch region of all subjects. Wall shear stress (WSS) distribution from CFD results at the aortic root is predominantly symmetric for TAVs but highly asymmetric for BAVs with the region opposite the raphe (fusion location of underdeveloped leaflets) being subjected to higher WSS. Asymmetry in the size and number of leaflets in BAVs and TAVs significantly influence vortical structures and WSS in the proximal aorta for all valve types and distal aorta for certain valve orientations of BAV. Analysis of vortical structures using 4D PCMRI data (on the left side) and wall shear stress data using CFD (on the right side).

Thoracic aortopathy in Marfan syndrome overlaps with mechanisms seen in bicuspid aortic valve disease

Background

Thoracic aortopathy is a serious complication which is more often seen in patients with Marfan syndrome (MFS) and patients with a bicuspid aortic valve (BAV) than in individuals with a tricuspid aortic valve (TAV). The identification of common pathological mechanisms leading to aortic complications in non-syndromic and syndromic diseases would significantly improve the field of personalized medicine.

Objective

This study sought to compare thoracic aortopathy between MFS, BAV, and TAV individuals.

Materials and methods

Bicuspid aortic valve (BAV; n = 36), TAV (n = 23), and MFS (n = 8) patients were included. Ascending aortic wall specimen were studied for general histologic features, apoptosis, markers of cardiovascular ageing, expression of synthetic and contractile vascular smooth muscle cells (VSMC), and fibrillin-1 expression.

Results

The MFS group showed many similarities with the dilated BAV. Both patient groups showed a thinner intima (p < 0.0005), a lower expression of contractile VSMCs (p < 0.05), more elastic fiber thinning (p < 0.001), lack of inflammation (p < 0.001), and a decreased progerin expression (p < 0.05) as compared to the TAV. Other features of cardiovascular ageing differed between the BAV and MFS. Dilated BAV patients demonstrated less medial degeneration (p < 0.0001), VSMC nuclei loss (p < 0.0001), apoptosis of the vessel wall (p < 0.03), and elastic fiber fragmentation and disorganization (p < 0.001), as compared to the MFS and dilated TAV.

Conclusion

This study showed important similarities in the pathogenesis of thoracic aortic aneurysms in BAV and MFS. These common mechanisms can be further investigated to personalize treatment strategies in non-syndromic and syndromic conditions.

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.

Development of the Human Arterial Valves: Understanding Bicuspid Aortic Valve

Abnormalities in the arterial valves are some of the commonest congenital malformations, with bicuspid aortic valve (BAV) occurring in as many as 2% of the population. Despite this, most of what we understand about the development of the arterial (semilunar; aortic and pulmonary) valves is extrapolated from investigations of the atrioventricular valves in animal models, with surprisingly little specifically known about how the arterial valves develop in mouse, and even less in human. In this review, we summarise what is known about the development of the human arterial valve leaflets, comparing this to the mouse where appropriate.

Leaflet fusion length is associated with aortic dilation and flow alterations in non-dysfunctional bicuspid aortic valve

OBJECTIVE

Bicuspid aortic valve (BAV), the most common congenital valve defect, is associated with increased risk of aortic dilation and related complications; however, current risk assessment is not effective. Most of BAV have three leaflets with a fusion between two of them of variable length. This study aimed to ascertain whether the extent of leaflet fusion (often called raphe) is related to aortic dilation and flow abnormalities in BAV with no significant valvular dysfunction.

METHODS

One hundred and twenty BAV patients with no significant valvular dysfunction or history of surgical repair or aortic valve replacement were consecutively and prospectively enrolled (September 2014-October 2018). Cardiac magnetic resonance protocol included a 4D flow sequence for haemodynamic assessment. Moreover, a stack of double-oblique cine images of the aortic valve were used to quantify fusion length (in systole) and leaflet length (diastole). Inter- and intra-observer reproducibility was tested in 30 randomly selected patients.

RESULTS

Aortic valve leaflet fusion was measurable in 112 of 120 (93%) cases with good reproducibility (ICC = 0.826). Fusion length varied greatly (range: 2.3-15.4 mm; mean: 7.8 ± 3.2 mm). After correction for demographic and clinical conditions, fusion length was independently associated with diameter and z-score at the sinus of Valsalva (p = 0.002 and p = 0.002, respectively) and ascending aorta (p = 0.028 and p = 0.046). Fusion length was positively related to flow asymmetry, vortices and circumferential wall shear stress, thereby possibly providing a pathophysiological link with aortic dilation.

CONCLUSIONS

Aortic valve fusion length is related to aortic dilation and flow abnormalities in BAV patients.

KEY POINTS

• The length of the fusion between leaflets in non-dysfunctional bicuspid aortic valves varies substantially and can be reliably measured by cine CMR. • Aortic valve leaflet fusion length is independently related to aortic sinus and ascending aorta diameter. • Increased flow asymmetry, circumferential wall shear stress and presence of vortices are positively related to aortic valve leaflet fusion length.

New Concepts in the Development and Malformation of the Arterial Valves

Although in many ways the arterial and atrioventricular valves are similar, both being derived for the most part from endocardial cushions, we now know that the arterial valves and their surrounding structures are uniquely dependent on progenitors from both the second heart field (SHF) and neural crest cells (NCC). Here, we will review aspects of arterial valve development, highlighting how our appreciation of NCC and the discovery of the SHF have altered our developmental models. We will highlight areas of research that have been particularly instructive for understanding how the leaflets form and remodel, as well as those with limited or conflicting results. With this background, we will explore how this developmental knowledge can help us to understand human valve malformations, particularly those of the bicuspid aortic valve (BAV). Controversies and the current state of valve genomics will be indicated.

Clinical-pathological correlations of BAV and the attendant thoracic aortopathies. Part 2: Pluridisciplinary perspective on their genetic and molecular origins

Bicuspid aortic valve (BAV) arises during valvulogenesis when 2 leaflets/cusps of the aortic valve (AOV) are fused together. Its clinical manifestations pertain to faulty AOV function, the associated aortopathy, and other complications surveyed in Part 1 of the present bipartite-series. Part 2 examines mainly genetic and epigenetic causes of BAV and BAV-associated aortopathies (BAVAs) and disease syndromes (BAVD). Part 1 explored the heterogeneity among subsets of patients with BAV and BAVA/BAVD, and investigated abnormal fluid dynamic stress and strain patterns sustained by the cusps. Specific BAV morphologies engender systolic outflow asymmetries, associated with abnormal aortic regional wall-shear-stress distributions and the expression/localization of BAVAs. Understanding fluid dynamic factors besides the developmental mechanisms and underlying genetics governing these congenital anomalies is necessary to explain patient predisposition to aortopathy and phenotypic heterogeneity. BAV aortopathy entails complex/multifactorial pathophysiology, involving alterations in genetics, epigenetics, hemodynamics, and in cellular and molecular pathways. There is always an interdependence between organismic developmental signals and genes-no systemic signals, no gene-expression; no active gene, no next step. An apposite signal induces the expression of the next developmental gene, which needs be expressed to trigger the next signal, and so on. Hence, embryonic, then post-partum, AOV and thoracic aortic development comprise cascades of developmental genes and their regulation. Interdependencies between them arise, entailing reciprocal/cyclical mutual interactions and adaptive feedback loops, by which developmental morphogenetic processes self-correct responding to environmental inputs/reactions. This Survey can serve as a reference point and driver for further pluridisciplinary BAV/BAVD studies and their clinical translation.

Coronary anatomy in Turner syndrome versus patients with isolated bicuspid aortic valves

OBJECTIVE

Variations in coronary anatomy, like absent left main stem and left dominant coronary system, have been described in patients with Turner syndrome (TS) and in patients with bicuspid aortic valves (BAV). It is unknown whether coronary variations in TS are related to BAV and to specific BAV subtypes.

AIM

To compare coronary anatomy in patients with TS with/without BAV versus isolated BAV and to study BAV morphology subtypes in these groups.

METHODS

Coronary anatomy and BAV morphology were studied in 86 patients with TS (20 TS-BAV, 66 TS-tricuspid aortic valve) and 86 patients with isolated BAV (37±13 years vs 42±15 years, respectively) by CT.

RESULTS

There was no significant difference in coronary dominance between patients with TS with and without BAV (25% vs 21%, p=0.933). BAVs with fusion of right and left coronary leaflets (RL BAV) without raphe showed a high prevalence of left coronary dominance in both TS-BAV and isolated BAV (both 38%). Absent left main stem was more often seen in TS-BAV as compared with isolated BAV (10% vs 0%). All patients with TS-BAV with absent left main stem had RL BAV without raphe.

CONCLUSION

The equal distribution of left dominance in RL BAV without raphe in TS-BAV and isolated BAV suggests that presence of left dominance is a feature of BAVs without raphe, independent of TS. Both TS and RL BAV without raphe seem independently associated with absent left main stems. Awareness of the higher incidence of particularly absent left main stems is important to avoid complications during hypothermic perfusion.

Investigation of raphe function in the bicuspid aortic valve and its influence on clinical criteria-A patient-specific finite element study

The aortic valve is normally composed of 3 cusps. In one common lesion, 2 cusps are fused together. The conjoined area of the fused cusps is termed raphe. Occurring in 1% to 2% of the population, the bicuspid aortic valve (BAV) is the most common congenital cardiac malformation. The majority of BAV patients eventually require surgery. There is a lack in the literature regarding modeling of the raphe (geometry and material properties), its role and its influence on BAV function. The present study aims to propose improvements on these aspects. Three patient-specific finite element models of BAVs were created based on 3D trans-esophageal echocardiography measurements, and assuming age-dependent material properties. The raphe was initially given the same material properties as its underlying cusps. Two levels of validation were performed; one based on the anatomical validation of the pressurized geometry in diastole (involving 7 anatomical measures), as simulated starting from the unpressurized geometry, and the other based on a functional assessment using clinical measurements in both systole and diastole (involving 16 functional measures). The pathology was successfully reproduced in the FE models of all 3 patients. To further investigate the role of the raphe, 2 additional scenarios were considered; (1) the raphe was considered as almost rigid, (2) the raphe was totally removed. The results confirmed the interpretation of the raphe as added stiffness in the fused cusp's rotation with respect to the aortic wall, as well as added support for stress distribution from the fused cusps to the aortic wall.

Abnormal aortic stiffness in patients with bicuspid aortic valve: phenotypic variation determined by magnetic resonance imaging

The aim of this study was to assess aortic stiffness in patients with bicuspid aortic valve (BAV), and to determine if differences exist among the BAV phenotypes. Stiffness was measured by pulse wave velocity (PWV) determined using velocity-encoded magnetic resonance imaging (VENC-MRI). VENC-MRI was performed in 100 BAV patients and 45 normal controls. PWV was determined between the mid ascending and mid descending aorta. The BAV phenotypes were characterized using steady-state free precession (SSFP) images acquired across the face of the aortic valve, and classified as follows: right-left cusp (R-L) fusion, right and non-coronary cusp (R-NC) fusion, and left and non-coronary cusp (L-NC) fusion. The following BAV phenotypes were identified: 76 R-L, 23 R-NC, and 1 L-NC fusion. BAV patients demonstrated significantly greater PWV compared to normal controls, after adjusting for age (9.16 vs. 3.83 m/s; p < 0.0001). Furthermore, PWV was significantly greater in patients with R-NC fusion than those with R-L fusion phenotype (12.27 vs. 7.97 m/s; p < 0.001). There was significantly increased PWV from VENC-MRI in BAV patients compared to normal controls. Thisis the first to demonstrate the association of different BAV phenotypes and aortic stiffness. VENC-MRI PWV assessment potentially represents a novel parameter for enhanced surveillance and may alter surgical triage of aorta in this high risk group.

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

Objective

In patients with bicuspid aortic valve (BAV), coronary anatomy is variable. High take-off coronary arteries have been described, but data are scarce, especially when associated with complex congenital heart disease (CHD). The purpose of this study was to describe coronary patterns in these patients.

Methods

In 84 postmortem heart specimens with BAV and associated CHD, position and height of the coronary ostia were studied and related to BAV morphology.

Results

High take-off right (RCA) and left coronary arteries (LCA) were observed in 23% and 37% of hearts, respectively, most frequently in hearts with hypoplastic left ventricle (HLV) and outflow tract anomalies. In HLV, high take-off was observed in 18/40 (45%) more frequently of LCA (n=14) than RCA (n=6). In hearts with aortic hypoplasia, 8/13 (62%) had high take-off LCA and 6/13 (46%) high take-off RCA. High take-off was seen 19 times in 22 specimens with perimembranous ventricular septal defect (RCA 8, LCA 11). High take-off was associated with type 1A BAV (raphe between right and left coronary leaflets), more outspoken for the RCA. Separate ostia of left anterior descending coronary artery and left circumflex coronary artery were seen in four hearts (5%), not related to specific BAV morphology.

Conclusion

High take-off coronary arteries, especially the LCA, occur more frequently in BAV with associated CHD than reported in normal hearts and isolated BAV. Outflow tract defects and HLV are associated with type 1A BAV and high take-off coronary arteries. Although it is unclear whether these findings in infants with detrimental outcome can be related to surviving adults, clinical awareness of variations in coronary anatomy is warranted.

Outflow tract septation and the aortic arch system in reptiles: lessons for understanding the mammalian heart

BACKGROUND

Cardiac outflow tract patterning and cell contribution are studied using an evo-devo approach to reveal insight into the development of aorto-pulmonary septation.

RESULTS

We studied embryonic stages of reptile hearts (lizard, turtle and crocodile) and compared these to avian and mammalian development. Immunohistochemistry allowed us to indicate where the essential cell components in the outflow tract and aortic sac were deployed, more specifically endocardial, neural crest and second heart field cells. The neural crest-derived aorto-pulmonary septum separates the pulmonary trunk from both aortae in reptiles, presenting with a left visceral and a right systemic aorta arising from the unseptated ventricle. Second heart field-derived cells function as flow dividers between both aortae and between the two pulmonary arteries. In birds, the left visceral aorta disappears early in development, while the right systemic aorta persists. This leads to a fusion of the aorto-pulmonary septum and the aortic flow divider (second heart field population) forming an avian aorto-pulmonary septal complex. In mammals, there is also a second heart field-derived aortic flow divider, albeit at a more distal site, while the aorto-pulmonary septum separates the aortic trunk from the pulmonary trunk. As in birds there is fusion with second heart field-derived cells albeit from the pulmonary flow divider as the right 6th pharyngeal arch artery disappears, resulting in a mammalian aorto-pulmonary septal complex. In crocodiles, birds and mammals, the main septal and parietal endocardial cushions receive neural crest cells that are functional in fusion and myocardialization of the outflow tract septum. Longer-lasting septation in crocodiles demonstrates a heterochrony in development. In other reptiles with no indication of incursion of neural crest cells, there is either no myocardialized outflow tract septum (lizard) or it is vestigial (turtle). Crocodiles are unique in bearing a central shunt, the foramen of Panizza, between the roots of both aortae. Finally, the soft-shell turtle investigated here exhibits a spongy histology of the developing carotid arteries supposedly related to regulation of blood flow during pharyngeal excretion in this species.

CONCLUSIONS

This is the first time that is shown that an interplay of second heart field-derived flow dividers with a neural crest-derived cell population is a variable but common, denominator across all species studied for vascular patterning and outflow tract septation. The observed differences in normal development of reptiles may have impact on the understanding of development of human congenital outflow tract malformations.

Computational comparison of regional stress and deformation characteristics in tricuspid and bicuspid aortic valve leaflets

The bicuspid aortic valve (BAV) is the most common congenital valvular defect and a major risk factor for secondary calcific aortic valve disease. While hemodynamics is presumed to be a potential contributor to this complication, the validation of this theory has been hampered by the limited knowledge of the mechanical stress abnormalities experienced by BAV leaflets and their dependence on the heterogeneous BAV fusion patterns. The objective of this study was to compare computationally the regional and temporal fluid wall shear stress (WSS) and structural deformation characteristics in tricuspid aortic valve (TAV), type-0, and type-I BAV leaflets. Arbitrary Lagrangian-Eulerian fluid-structure interaction models were designed to simulate the flow and leaflet dynamics in idealized TAV, type-0, and type-I BAV geometries subjected to physiologic transvalvular pressure. The regional leaflet mechanics was quantified in terms of temporal shear magnitude (TSM), oscillatory shear index (OSI), temporal shear gradient (TSG), and stretch. The simulations identified regions of WSS overloads and increased WSS bidirectionality (174% increase in temporal shear magnitude, 0.10 increase in OSI on type-0 leaflets) in BAV leaflets relative to TAV leaflets. BAV leaflets also experienced larger radial deformations than TAV leaflets (4% increase in type-0 BAV leaflets). Type-I BAV leaflets exhibited contrasted WSS environments marked by WSS overloads on the non-coronary leaflet and sub-physiologic WSS levels on the fused leaflet. This study provides important insights into the mechanical characteristics of BAV leaflets, which may further our understanding of the role played by hemodynamic forces in BAV disease. Copyright © 2016 John Wiley & Sons, Ltd.

KinCor, a national registry for paediatric patients with congenital and other types of heart disease in the Netherlands: aims, design and interim results

Objective

Studies in children with heart disease have been hampered by a lack of easily identifiable patient groups. Currently, there are few prospective population-based registries covering the entire spectrum of heart disease in children. KinCor is a Dutch national registry for children with heart diseases. This paper presents the aims, design and interim results of the KinCor project.

Methods

All children presenting at a Dutch university medical centre with a diagnosis of heart disease from 2012 onwards were eligible for registration in the KinCor database. Data entry is through a web-based portal. Entry codes have been synchronised with the European Paediatric Cardiac Coding system, allowing coupling with similar databases for adults, such as CONCOR.

Results

Between June 2012 and July 2015, 8421 patients were registered (76 % of those eligible). Median age of the patients was 9.8 years, 44.7 % were female; 6782 patients had morphological congenital heart disease. The most prevalent morphological congenital heart defects were ventricular septal defects (18 %), Tetralogy of Fallot (10 %) and transposition of great arteries (9 %). For 42 % of the patients additional diagnoses were registered. Sixty percent of patients had undergone at least one intervention (catheter intervention or surgery).

Conclusion

The KinCor database has developed into a large registry of data of children with all types of heart disease and continues to grow. This database will provide the opportunity for epidemiological research projects on congenital and other types of heart disease in children. Entry codes are shared with the CONCOR database, which may provide a unique dataset.

Coronary anatomy as related to bicuspid aortic valve morphology

OBJECTIVE

Variable coronary anatomy has been described in patients with bicuspid aortic valves (BAVs). This was never specified to BAV morphology, and prognostic relevance of coronary vessel dominance in this patient group is unclear. The purpose of this study was to evaluate valve morphology in relation to coronary artery anatomy and outcome in patients with isolated BAV and with associated aortic coarctation (CoA).

METHODS

Coronary anatomy was evaluated in 186 patients with BAV (141 men (79%), 51±14 years) by CT and invasive coronary angiography. Correlation of coronary anatomy was made with BAV morphology and coronary events.

RESULTS

Strictly bicuspid valves (without raphe) with left-right cusp fusion (type 1B) had more left dominant coronary systems compared with BAVs with left-right cusp fusion with a raphe (type 1A) (48% vs. 26%, p=0.047) and showed more separate ostia (28% vs. 9%, p=0.016). Type 1B BAVs had more coronary artery disease than patients with type 1A BAV (36% vs. 19%, p=0.047). More left dominance was seen in BAV patients with CoA than in patients without (65% vs. 24%, p<0.05).

CONCLUSIONS

The incidence of a left dominant coronary artery system and separate ostia was significantly related to BAVs with left-right fusion without a raphe (type 1B). These patients more often had significant coronary artery disease. In patients with BAV and CoA, left dominancy is more common.