Predictors of ascending aortic dilation in bicuspid aortic valve disease: a five-year prospective study

Bicuspid aortic valves are associated with aortic dilation and dissection. There is a paucity of prospective studies evaluating changes in aortic size over time in adult subjects with bicuspid aortic valves.

A total of 115 subjects with asymptomatic bicuspid aortic valves were enrolled from 2003 to 2008 and followed prospectively over 5 years. Clinical and family histories, as well as transthoracic echocardiograms, were obtained at baseline, and echocardiograms were performed annually thereafter.

The mean age of subjects was 41.8 ± 12.8 years, and 61% were male. Ascending aortic size at baseline averaged 35.5 ± 5.6 mm and increased in 71.1% of subjects (mean, 0.66 ± 0.05 mm/y; range, 0.2-2.3 mm/y) over an average of 4.8 years. In 15.6% of subjects, the rate of change exceeded 1 mm/y. The average rate of ascending aortic dilation for all subjects was 0.47 ± 0.05 mm/y (P < .001). A family history of aortic valve disease was associated with progression in both unadjusted (P = .029) and logistic regression analyses adjusted for age, gender, and body surface area (odds ratio, 13.7; P = .021). Multivariate analysis did not find leaflet orientation or moderate to severe aortic valve dysfunction as independent predictors of aortic dilation.

We found that in subjects with bicuspid aortic valve, studied prospectively, there was an annual rate of ascending aortic dilation of 0.47 mm/y. In contrast to previous reports, leaflet orientation and aortic valve dysfunction were not independent predictors of aortic dilation. A family history of aortic valve disease was associated with a significantly increased risk of increasing ascending aortic size.