Abstract
Background: Bicuspid aortic valve is the most common congenital heart
defect and predisposes patients to developing aortic stenosis more
frequently and at a younger age than the general population. However,
the influence of bicuspid aortic valve on the rate of progression of
aortic stenosis remains unclear. Methods: In 236 patients (177 tricuspid
aortic valve, 59 bicuspid aortic valve) matched by initial severity of
mild or moderate aortic stenosis, we retrospectively analyzed baseline
echocardiogram at diagnosis with latest available follow-up
echocardiogram. Baseline comorbidities, annualized progression rate of
hemodynamic parameters, and hazard of aortic valve replacement were
compared between valve phenotypes. Results: Median echocardiographic
follow-up was 2.6 (IQR 1.6-4.2) years. Patients with tricuspid aortic
stenosis were significantly older with more frequent comorbid
hypertension and congestive heart failure. Median annualized progression
rate of mean gradient was 2.3 (IQR 0.6-5.0) mmHg/year vs. 1.5 (IQR
0.5-4.1) mmHg/year (p=0.5), and that of peak velocity was 0.14 (IQR
0-0.31) m/s/year vs. 0.10 (IQR 0.04-0.26) m/s/year (p=0.7) for tricuspid
vs. bicuspid aortic valve, respectively. On multivariate analyses,
bicuspid aortic valve was not significantly associated with more rapid
progression of aortic stenosis. In a stepwise Cox proportional hazards
model adjusted for baseline mean gradient, bicuspid aortic valve was
associated with increased hazard of aortic valve replacement (HR: 1.7,
95% CI [1.0, 3.0], p=0.049). Conclusion: Bicuspid aortic valve may
not significantly predispose patients to more rapid progression of mild
or moderate aortic stenosis. Guidelines for echocardiographic
surveillance of aortic stenosis need not be influenced by valve
phenotype.