Article

Morphology of bicuspid aortic valve in children and adolescents

Harvard University, Cambridge, Massachusetts, United States
Journal of the American College of Cardiology (Impact Factor: 16.5). 11/2004; 44(8):1648-51. DOI: 10.1016/j.jacc.2004.05.063
Source: PubMed

ABSTRACT

The aim of this study was to determine the relationship between aortic valve morphology and valve dysfunction.
The morphology of the bicuspid or bicommissural aortic valve (BAV) may predict the severity of valve dysfunction. Therefore, we assessed the relationship between BAV, aortic coarctation, and the degree of valve pathology in children.
A retrospective review of 1,135 patients with BAV who were identified between 1986 and 1999 was performed. Patients younger than 18 years of age with BAV that was identifiable via echocardiography were included. The most recent or last study of each patient before intervention or endocarditis was reviewed. Mild stenosis was defined as a valve gradient > or =2 m/s, moderate or greater aortic stenosis as > or =3.5 m/s. Aortic regurgitation was quantified using standard criteria.
Median age was 3 years (range, 1 day to 17.9 years), and 67% of the patients were male. Right-coronary and left-coronary leaflet fusion were the most common types of BAV (70%). Aortic stenosis that was moderate or greater was observed most often in patients with right-coronary and non-coronary leaflet fusion (odds ratio 2.4, 95% confidence interval 1.6 to 3.6; p < or = 0.001). Similarly, right-coronary and non-coronary leaflet fusion was more often associated with moderate aortic regurgitation or greater (odds ratio 2.4, 95% confidence interval 1.2 to 4.7; p = 0.01). The majority of patients with aortic coarctation had fusion of the right-coronary and left-coronary leaflets (89%), and aortic coarctation was associated with lesser degrees of valve stenosis or regurgitation.
Analysis of BAV morphology is of clinical and prognostic relevance. Fusion of the right-coronary and non-coronary leaflets was associated with more significant valve pathology, whereas fusion of the right-coronary and left-coronary leaflets was associated overwhelmingly with aortic coarctation and less aortic valve pathology.

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Available from: Peter Lang, Jan 27, 2015
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    • "Right coronary and left coronary (R-L) cusp fusion is more common than right coronary and non-coronary (R-NC) cusp fusion. Moreover, R-L cusp fusion is more often associated with additional cardiac malformations, whereas R-NC cusp fusion is more likely to be associated with aortic valve dysfunction [3]. The etiologies of these associations are unknown. "
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    ABSTRACT: Background Bicuspid aortic valve (BAV) is the most common type of congenital heart disease with a population prevalence of 1-2%. While BAV is known to be highly heritable, mutations in single genes (such as GATA5 and NOTCH1) have been reported in few human BAV cases. Traditional gene sequencing methods are time and labor intensive, while next-generation high throughput sequencing remains costly for large patient cohorts and requires extensive bioinformatics processing. Here we describe an approach to targeted multi-gene sequencing with combinatorial pooling of samples from BAV patients. Methods We studied a previously described cohort of 78 unrelated subjects with echocardiogram-identified BAV. Subjects were identified as having isolated BAV or BAV associated with coarctation of aorta (BAV-CoA). BAV cusp fusion morphology was defined as right-left cusp fusion, right non-coronary cusp fusion, or left non-coronary cusp fusion. Samples were combined into 19 pools using a uniquely overlapping combinatorial design; a given mutation could be attributed to a single individual on the basis of which pools contained the mutation. A custom gene capture of 97 candidate genes was sequenced on the Illumina HiSeq 2000. Multistep bioinformatics processing was performed for base calling, variant identification, and in-silico analysis of putative disease-causing variants. Results Targeted capture identified 42 rare, non-synonymous, exonic variants involving 35 of the 97 candidate genes. Among these variants, in-silico analysis classified 33 of these variants as putative disease-causing changes. Sanger sequencing confirmed thirty-one of these variants, found among 16 individuals. There were no significant differences in variant burden among BAV fusion phenotypes or isolated BAV versus BAV-CoA. Pathway analysis suggests a role for the WNT signaling pathway in human BAV. Conclusion We successfully developed a pooling and targeted capture strategy that enabled rapid and cost effective next generation sequencing of target genes in a large patient cohort. This approach identified a large number of putative disease-causing variants in a cohort of patients with BAV, including variants in 26 genes not previously associated with human BAV. The data suggest that BAV heritability is complex and polygenic. Our pooling approach saved over $39,350 compared to an unpooled, targeted capture sequencing strategy.
    Full-text · Article · Sep 2014 · BMC Medical Genomics
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    • "The findings and hypothesis are summarized in Fig. 5. Finally, we considered the morphological appearance of the commissure position as a determinant of susceptibility, since commissure position, which can clinically be analysed echocardiographically , is reported to be important in predicting future aortopathy [8] [11]. Previously, several studies reported that BAVs with an RCC/LCC BAV, which is the most common variant, are associated with more aortic dilatation in adults, whereas BAVs with fusion of the RCC/NCC are responsible for valve dysfunction at a younger age [13] [14] [15] [16] [17] [18]. Although the groups were small in our study, the orientation of the commissure and position of the raphe was in line with previous findings: RCC/NCC was most apparent in the BAa (the considered non-susceptible group), while the RCC/LCC was seen more often in the BAb group (the considered susceptible group) and in BAD patients (Table 2). "
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    ABSTRACT: OBJECTIVES The clinical course of many patients with a bicuspid aortic valve (BAV) is complicated by ascending aortic dilatation. Currently, the indication for aortic surgery is solely based on the aortic diameter and subsequently only a small proportion of BAV patients undergoing valve surgery require concomitant ascending aortic replacement based on these recommendations. Unfortunately, a substantial number of BAV patients still develop aortic dilatation in the future and would potentially benefit from a more aggressive approach towards ascending aortic replacement. We, therefore, designed this study to identify molecular biological markers in the aortic wall predictive of aortopathy in BAV.
    Full-text · Article · Aug 2014 · European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery
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    • "The gender distribution of our BAV patients was the same as that of other studies [Fernandes et al. 2004; Mahle et al. 2010], with 76% male patients. Likewise, consistent with the finding of Pees and Michel-Behnke's study [Pees and Michel-Behnke, 2012], male gender does not have any significant effect on aortic distensibility. "
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    Full-text · Article · May 2014 · Therapeutic Advances in Cardiovascular Disease
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