Retrospective study to identify predictors of the presence and rapid progression of aortic dilatation in patients with bicuspid aortic valves.

Background: Aortic dilatation is common among adults with bicuspid aortic valves (BAV). Predictors of risk and progression of aortic dilatation are not well described in this setting.

Methods: We analyzed retrospective data on the presence of dilation in several aortic segments in 156 adult patients with BAV who had serial echocardiograms performed at least 1 year apart. Various risk factors for the presence and progression of aortic dilatation were identified.

Results: Mean echocardiographic follow-up was 3.8 +/- 1.4 years, yielding a total of 582 patient-years. Independent predictors of having a dilated aorta at baseline were age (odds ratio [OR] 1.06, 95% CI 1.03-1.09), body surface area (OR 8.78, 95% CI 1.08-71.70) and moderate to severe aortic regurgitation (OR 6.38, 95% CI 2.51-16.20). During echocardiographic follow-up, 16 (15.2%) patients developed dilatation (incidence 4 cases per 100 patient-years). Mean annual rates of progression were estimated at 0.37 mm (95% CI 0.17-0.57), 0.18 mm (95% CI 0.05-0.31), 0.17 mm (95% CI 0.06-0.29) and 0.18 mm (95% CI 0.05-0.31) for the ascending aorta, sinotubular junction, aortic sinus and aortic annulus, respectively. Fusion of the right and left valve leaflets was associated with rapid aortic dilatation (OR 2.92, 95% CI 1.15- 7.41) whereas prior coarctation repair was associated with protection from rapid aortic dilatation (OR 0.13, 95% CI 0.04-0.40).

Conclusions: Patients with BAV and increased age, high body surface area and moderate to severe aortic regurgitation are more likely to have a dilated aorta. Patients with right-to-left leaflet fusion are at increased risk of rapid aortic dilatation.