The Association Between Aortic Valve Leaflet Morphology and Patterns of Aortic Dilation in Patients With Bicuspid Aortic Valves.

Background: Dilation of the aorta is a frequent complication in patients with bicuspid aortic valves. The aim of this study was to determine the relationship between the subtype of leaflet fusion, right and noncoronary leaflet (R/N) fusion versus right and left leaflet (R/L) fusion, and the patterns of aortic dilation and valve dysfunction in young patients with bicuspid aortic valves.

Methods: We performed a retrospective review of 642 patients who presented with bicuspid aortic valves between 1994 and 2014. Of these patients, 210 (33%) had aortic dilation (z score >3) by echocardiogram. For each patient, the most recent study or the last study before intervention was reviewed.

Results: Median patient age was 15 years (range, 0 to 40 years) with patients with R/N fusion being younger. The most prevalent subtype was R/N fusion (R/N, n = 114, 54% versus R/L, n = 96, 46%). Dilation of the ascending aorta was seen more often in patients with R/N fusion (R/N, 88% versus R/L, 68%; p = 0.004), whereas the prevalence of dilation of the sinuses of Valsalva was significantly higher in patients with R/L fusion (R/L, 46% versus R/N, 20%; p = 0.01). The magnitude of dilation differed as well. The z value of the sinuses of Valsalva was significantly higher in patients with R/L fusion (R/L, 2.03 versus R/N, 1.2; p = 0.003), whereas the z values of the ascending aorta and sinotubular junction were similar between the groups. Patients with R/N fusion were more likely to have aortic stenosis, and within the R/N group, patients with aortic insufficiency had a greater degree of ascending aorta dilation (p = 0.04).

Conclusions: Our study suggests that in young patients with bicuspid aortic valves and aortic dilation, aortic valve morphology may be associated with the patterns of aortic dilation and valve dysfunction. Patients with R/N fusion were more likely to have ascending aorta dilation, whereas patients with R/L fusion were more likely to have dilation of the aortic root. In addition, patients with R/N fusion presented at a younger age and were more likely to have aortic stenosis. Recognition of these differences may eventually be helpful for patient counseling and the planning of follow-up.