Recent case series
have identified groups of asymptomatic aortic stenosis patients at
very high risk of becoming symptomatic and requiring valve replacement.
Physicians can identify high-risk asymptomatic patients using frequent
clinical examination, exercise tolerance testing, and echocardiography.
Management of aortic stenosis in the asymptomatic patient is a
clinical challenge. Patients with non-severe stenosis should receive
follow-up evaluation every 1 to 2 years. However, if the patient's
stenosis is severe, then the patient may be at high risk, and may
qualify for aortic valve replacement.
If the asymptomatic patient with severe stenosis is going to receive
other cardiac surgery, such as coronary artery bypass graft, then
current guidelines support aortic valve replacement. The American
Heart Association/American College of Cardiology published these
guidelines in 1998.
Otherwise, physicians should consider the natural history of the
disease. Recent reviews of case series have identified groups of
clinically asymptomatic patients at very high risk of becoming symptomatic
in a brief period of time.
For example, the rate of increase in aortic jet velocity is a predictor
of clinical outcome. An important predictor of event-free survival
is severity of valve calcification on electrocardiogram.
Based on these and other findings, clinicians can identify patients
who may benefit from earlier aortic valve replacement. The main
tools include frequent clinical examination, exercise tolerance
testing, and echocardiography.
Dr. Braunwald suggested an algorithm for the management of asymptomatic
patients with severe aortic stenosis:
*The patient scheduled for other cardiac surgery would already
qualify for the aortic valve.
* If not, the physician can perform an exercise tolerance test
under careful observation.
The patient who becomes hypotensive or symptomatic should receive
aortic valve replacement. If the exercise test is negative, go to
the next step.
* If the patient has a severely calcified valve and an increasing
aortic jet velocity, Dr. Braunwald said he would strongly consider
valve replacement. But if the patient does not have one of these
risk factors, the physician can schedule a follow-up clinical exam
and exercise tolerance test every six months.
An intriguing future possibility is that statins may help arrest
the progression of aortic stenosis. Novaro and others recently published
this report in the October 30, 2001 edition of Circulation. These
data are the first to suggest that this important valve abnormality
may respond to medical treatment.
|