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.