Bicuspid Aortic Valve: Inter-Racial Difference in Frequency and Aortic Dimensions

Study Questions:

Are there differences in bicuspid aortic valve (BAV) morphology, degree of valve dysfunction, and aortopathy between Caucasian (C) and African American (AA) patients?

Methods:

An echocardiography database at a large urban academic tertiary referral center was queried for all patients with a diagnosis of BAV. Exclusion criteria included inability to confirm BAV on reanalysis, other complex congenital disease, non-C or AA race, and poor visualization of the ascending aorta. Prevalence of BAV was calculated, BAV morphology was classified, and the degree of valvular dysfunction and aortic diameters were recorded.

Results:

Of over 40,000 patients included in the database, 229 patients (0.59%) had a diagnosis of BAV. After exclusion criteria were applied, 183 patients were studied (C: 138 [75%] vs. AA: 45 [25%]), and 126 patients (68%) were male. Mean age overall was 45 years, with significantly older age noted in the AA group. No other significant baseline differences were seen, except more hypertension and diuretic use in the AA population. The overall prevalence of BAV in 26,570 AA patients screened was 0.17% versus 1.1% in the Caucasian population (p = 0.001). There were no significant differences in valve morphology or valvular dysfunction. However, there was a trend toward more normally functioning BAVs in the AA population (AA: 44% vs. C: 29%, p = 0.067). Aortic dimensions were significantly different between groups, with the C cohort having larger unadjusted and adjusted aortic dimensions at all levels, but were particularly significant at the level of the ST junction.

Conclusions:

This retrospective study suggests that there may be inter-racial differences and potential modifiers in the phenotypic expression of BAV.

Perspective:

Although BAV is very common, it is phenotypically diverse, and we are just beginning to understand the complex genetics associated with the disease. Due to the geographic location of the study site, AA patients were highly represented, but still had a much lower prevalence of BAV and less associated aortopathy despite similarities in valve morphology and function. Although this is a small study in a highly selected group of patients, the findings are interesting. The continued discovery of important BAV disease modifiers will help individualize management of these patients who require frequent surveillance and follow-up.

Keywords: Echocardiography


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