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.

Summary: International Consensus Statement on Nomenclature and Classification of the Congenital Bicuspid Aortic Valve and Its Aortopathy, for Clinical, Surgical, Interventional and Research Purposes.

This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.

International Consensus Statement on Nomenclature and Classification of the Congenital Bicuspid Aortic Valve and Its Aortopathy, for Clinical, Surgical, Interventional and Research Purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.

Summary: International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional, and research purposes.

This International evidence-based nomenclature and classification consensus on the congenital bicuspid aortic valve and its aortopathy recognizes 3 types of bicuspid aortic valve: 1. Fused type, with 3 phenotypes: right-left cusp fusion, right-non cusp fusion and left-non cusp fusion; 2. 2-sinus type with 2 phenotypes: Latero-lateral and antero-posterior; and 3. Partial-fusion or forme fruste. This consensus recognizes 3 bicuspid-aortopathy types: 1. Ascending phenotype; root phenotype; and 3. extended phenotypes.

International consensus statement on nomenclature and classification of the congenital bicuspid aortic valve and its aortopathy, for clinical, surgical, interventional and research purposes.

This International Consensus Classification and Nomenclature for the congenital bicuspid aortic valve condition recognizes 3 types of bicuspid valves: 1. The fused type (right-left cusp fusion, right-non-coronary cusp fusion and left-non-coronary cusp fusion phenotypes); 2. The 2-sinus type (latero-lateral and antero-posterior phenotypes); and 3. The partial-fusion (forme fruste) type. The presence of raphe and the symmetry of the fused type phenotypes are critical aspects to describe. The International Consensus also recognizes 3 types of bicuspid valve-associated aortopathy: 1. The ascending phenotype; 2. The root phenotype; and 3. Extended phenotypes.

Prevalence of Bicuspid Aortic Valve and Associated Aortopathy in Newborns in Copenhagen, Denmark.

Importance: The prevalence and characteristics of bicuspid aortic valve (BAV) are mainly reported from selected cohorts. BAV is associated with aortopathy, but it is unclear if it represents a fetal developmental defect or is secondary to abnormal valve dynamics. Objective: To determine the prevalence of BAV and BAV subtypes and to describe the associated aortopathy in a large, population-based cohort of newborns. Design, Setting, and Participants: The Copenhagen Baby Heart Study was a cross-sectional, population-based study open to all newborns born in Copenhagen between April 1, 2016, and October 31, 2018. Newborns with BAV were matched 1:2 to newborns with a tricuspid aortic valve (non-BAV group) on sex, singleton/twin pregnancy, gestational age, weight, and age at time of examination. Exposures: Transthoracic echocardiography within 60 days after birth. Main Outcomes and Measures: Primary outcome was BAV prevalence and types, ie, number of raphes and spatial orientation of raphes or cusps (no raphes), according to the classification system of Sievers and Schmidtke (classified as type 0, 1, or 2, with numbers indicating the number of raphes). Secondary outcome was valve function and BAV-associated aortopathy, defined as aortic diameter z score of 3 or greater or coarctation. Results: In total, 25 556 newborns (51.7% male; mean age, 12 [SD, 8] days) underwent echocardiography. BAV was diagnosed in 196 newborns (prevalence, 0.77% [95% CI, 0.67%-0.88%]), with male-female ratio 2.1:1. BAV was classified as type 0 in 17 newborns (8.7% [95% CI, 5.5%-13.5%]), type 1 in 178 (90.8% [95% CI, 86.0%-94.1%]) (147 [75.0% {95% CI, 68.5%-80.5%}] right-left coronary raphe, 27 [13.8% {95% CI, 9.6%-19.3%}] right coronary-noncoronary raphe, 4 [2.0% {95% CI, 0.8%-5.1%}] left coronary-noncoronary raphe), and type 2 in 1 (0.5% [95% CI, 0.1%-2.8%]). Aortic regurgitation was more prevalent in newborns with BAV (n = 29 [14.7%]) than in those without BAV (1.3%) (absolute % difference, 13.4% [95% CI, 7.8%-18.9%]; P < .001). Newborns with BAV had higher flow velocities across the valve (0.67 [95% CI, 0.65-0.69] m/s vs 0.61 [95% CI, 0.60-0.62] m/s; mean difference, 0.06 m/s [95% CI, 0-0.1]) and larger aortic root and tubular ascending aortic diameters than those without BAV (10.7 [95% CI, 10.7-10.9] mm vs 10.3 [95% CI, 10.2-10.4] mm; mean difference, 0.43 mm [95% CI, 0.2-0.6 mm] and 9.8 [95% CI, 9.6-10.0] mm vs 9.4 [95% CI, 9.3-9.5] mm; mean difference, 0.46 mm [95% CI, 0.30-0.70], respectively) (P < .001 for all). Aortopathy was seen in 65 newborns (33.2%) with BAV (62 with aortic z score ≥3; 3 with coarctation). Conclusions and Relevance: Among newborns in Copenhagen, the prevalence of BAV was 0.77%. Aortopathy was common in newborns with BAV, suggesting that it also represents a fetal malformation.