Introduction
Aortic stenosis (AS) is a common cause of valvular heart disease
worldwide. Its prevalence increases with age, ranging from 4.6%-6.4%
in U.S. adults aged 75 years and older.1, 2 The most
common etiology of aortic stenosis is degenerative calcification, which
is primarily associated with aging as well as other cardiovascular
disease. However, the presence of bicuspid aortic valve (BAV) represents
a major risk factor in the development of AS in younger populations and
is present in 65% of adults aged 60 and younger undergoing aortic valve
replacement for aortic stenosis.3 While patients with
BAV are known to develop AS more frequently and earlier than patients
with tricuspid aortic valve (TAV), it remains uncertain whether BAV is
associated with faster progression of AS severity once AS develops,
which is important to guide screening and intervention
practices.4
While the progression rate of AS varies widely among individuals, older
age, male sex, coronary artery disease, plasma levels of oxidized
phospholipids, and baseline hemodynamic severity have all been
associated with more rapid progression.5-8 BAV has
been implicated in certain studies,9, 10 but others
have shown no difference in AS progression rate between BAV and TAV
phenotypes.5, 11 Furthermore, these findings were
drawn from post hoc analyses of clinical trials aimed at determining
effects of metabolic syndrome and plasma lipids on AS disease
progression. As a result, these studies examined very small cohorts of
BAV patients (N<41), representing a significant limitation in
the current literature. These findings attest to the need for more
investigations to better understand progression of more-than-mild AS in
BAV patients.
Using a healthcare system-wide echocardiographic database, we aim to
determine the hemodynamic progression rate of mild and moderate severe
aortic stenosis in patients with BAV as compared to patients with TAV.