Effect of Bicuspid Versus Tricuspid Aortic Valve Morphology on the Fate of the Ascending Aorta.

Background: Bicuspid aortic valves are associated with ascending aortic pathology, but their impact on long-term outcomes, including aortic growth and adverse events, remains unclear.

Results: This prospective cohort-study included adult patients undergoing aortic valve surgery or ascending aortic surgery at a single center (2007-2013). The primary outcome was aortic diameter growth; secondary outcomes included all-cause mortality and adverse aortic events. Inverse probability of treatment weighting was used to adjust for baseline differences. Among 570 patients, 204 underwent echocardiographic follow-up, and 566 were followed for adverse aortic events. At 10-year follow-up, ascending aortic diameter increased significantly (mean 4 mm, P<0.001), with no difference between patients with BAV and TAV (P=0.68). After multivariable adjustment, there was no difference in all-cause mortality (HR, 0.87 [95% CI, 0.65-1.18]), but BAV was associated with a decreased risk of adverse aortic events (HR, 0.39 [95% CI, 0.19-0.82]). Concomitant ascending aortic surgery was associated with an increased risk of adverse aortic events in patients with TAV (HR, 8.89 [95% CI, 3.36-23.6]) but was associated with a decreased risk in patients with BAV (HR, 0.06 [95% CI, 0.01-0.29]).

Conclusions: Ten years after surgery, ascending aortic growth occurred regardless of valve morphology. Adverse aortic events were more common in patients with TAV, whereas patients with BAV benefited from concomitant ascending aortic surgery. These findings suggest a more liberal approach to ascending aortic surgery in patients with BAV undergoing valve replacement, but improved risk stratification is needed.