Bicuspid and unicuspid aortic valves: Different phenotypes of the same disease? Insight from the GenTAC Registry

Abstract

Background: Unicuspid aortic valve (UAV) is a rare disorder, often difficult to distinguish from bicuspid aortic valve (BAV). BAV and UAV share valve pathology such as the presence of a raphe, leaflet fusion, aortic stenosis, aortic regurgitation, and/or ascending aortic dilatation, but a comprehensive echocardiographic comparison of patients with UAV and BAV has not been previously performed.

Methods: We investigated UAV and BAV patients at an early stage of disease included in GenTAC, a national registry of genetically related aortic aneurysms and associated cardiac conditions. Clinical and echocardiographic data from the GenTAC Registry were compared between 17 patients with UAV and 17 matched-controls with BAV.

Results: Baseline characteristics including demographics, clinical findings including family history of BAV and aortic aneurysm/coarctation, and echocardiographic variables were similar between BAV and UAV patients; aortic stenosis was more common and more severe in patients with UAV. This was evidenced by higher mean and peak gradient, smaller aortic valve area, and more advanced valvular degeneration (all P < .05). There were no significant differences in aortic dimensions, with a similar pattern of enlargement of the ascending aorta.

Conclusions: The similar baseline characteristics with more accelerated aortic valve degeneration and stenosis suggest that UAV represents an extreme in the spectrum of BAV syndromes. Therefore, it is reasonable to consider application of recommendations for the management of patients with BAV to those with the rarer UAV.

Keywords: bicuspid aortic valve; congenital heart disease; unicuspid aortic valve.

Figure 1

Examples of bicuspid and unicuspid aortic valves (BAV and UAV, respectively) and typical ascending aortic enlargement in these conditions. BAV was defined as having two commissures (arrows) and an oval, “football-like” opening (left panel). UAV was defined as a valve with one (or none) commissure and a rounded, “soccer ball-like” opening (center panel). Both examples are shown from a parasternal short axis view. In both conditions, enlargement of the ascending aorta (classically described for BAV) was frequently found, shown in the right panel from a suprasternal notch view (dilated ascending aorta marked in full line, normal descending in dotted line).