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Back to Cardiovascular Diseases
Aortic valve stenosis
Updated: September 22, 2006
Goal of treatment
The goal of treatment is to allow the heart to get more blood
into general circulation. Various medicines can help improve
overall blood supply to the body and the heart. They can also
help reduce the person's symptoms.
Treatment
In some cases, surgery is recommended to correct the aortic
stenosis. Balloon valvuloplasty is a technique that lowers the
pressure across the valve by slightly enlarging the opening.
This is usually done when someone is not stable enough for
corrective surgery. More often, heart valve surgery is performed
to correct the problem with the aortic valve.
Patients with (predominant) aortic stenosis fall into one of
four categories of severity:
- valve area > 1.2 cm2………………………….mild
- valve area 1.0 to 1.2 cm2…………………….moderate
- valve area 0.8 to 1.0 cm2…………………….severe
- valve area < 0.8 cm2………………………….critical
Asymptomatic patients with mild to moderate aortic stenosis
should have medical follow-up with regular inquiry as to changes
in exercise tolerance or other symptoms. Serial
echocardiographic examination should be based on an
understanding of the natural history of the lesion, as outlined
below. Patients should avoid strenuous activity, and
particularly avoid post-prandial exertion. Infective
endocarditis precautions following American Heart Association
guidelines must be emphasized at each visit.
Current evidence indicates that calcific aortic stenosis
progresses, on the average, at a rate of about 0.1 cm2 per year
decline in valve area. To date, no medical therapy exists for
the treatment of degenerative aortic stenosis. The possible
impact of 'secondary prevention' measures, particularly lipid
lowering with HMG-CoA reductase inhibitors (statins), on the
progression of aortic stenosis is under investigation.

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Hypertension occurs in about 20% to 30% of patients with mild to
moderate aortic stenosis and should be managed with angiotensin-converting
enzyme inhibitors or angiotensin receptor blockers titrated
slowly. Selected patients may be given modest doses of
concomitant beta-blockers.
A supervised exercise tolerance test may provide helpful
objective assessment in patients with echocardiographic evidence
of moderate aortic stenosis who report atypical symptoms, who
minimize complaints, or who are sedentary and therefore might
not experience exercise intolerance. Functional limitation with
inability to exercise to levels greater than 6 metabolic
equivalents (METs) may, in some cases, be viewed as a "symptom."
Stress testing is not advocated for patients with very severe
left ventricular outflow obstruction.
Symptomatic patients, ie, those with angina, syncope, dyspnea,
with moderate, severe, or critical aortic stenosis should
undergo valve replacement. Indications for aortic valve surgery
include moderate aortic stenosis in patients requiring coronary
bypass grafting and/or any other cardiac surgery,
exercise-induced hypotension, and asymptomatic severe aortic
stenosis with evidence of left ventricular dysfunction. Smoking
cessation and diabetic control are mandatory after the
replacement. Dental care should be completed with antibiotic
prophylaxis before surgery.
The advantages and drawbacks of mechanical versus
bioprosthetic valves should be discussed with the patient and
his or her family. Often the choice of prosthesis is
straightforward, but younger patients in particular may have
special needs, which should be addressed Bioprosthetic valves
offer the advantage of not requiring long-term oral
anticoagulation, but have the drawback of relatively limited
durability. In contrast, mechanical valves offer long-term
durability, but require lifelong warfarin therapy. The generally
accepted risk of serious bleeding with warfarin is on the order
of 3% per year. Childbearing in women and vigorous sports
activities in men are contra-indications to chronic oral
anticoagulation with warfarin, and may figure importantly in the
choice of valves. In general, bioprosthetic valves are preferred
in patients over the age of 60 years and mechanical valves under
the age of 50. Homograft aortic valve replacement with a
cryopreserved cadaveric valve may offer specific advantages in
patients with infective endocarditis or with disease of the
aortic root. If significant narrowing of the coronary arteries
is found, coronary artery bypass graft surgery (CABG) can be
performed during aortic valve replacement surgery.
Follow up
Successful replacement of the valve restores normal blood
flow. The long-term outcome is usually very good. Artificial
valves wear out over a period of years. Their function is
monitored, and the valves are replaced as necessary. A
prosthetic heart valve commits a patient to continued infective
endocarditis prophylaxis, regular cardiac follow-up, and often
to continued medical therapy, including anticoagulation with
warfarin for those with mechanical prostheses. Re-operation may
be required for malfunction of the prosthetic valve. In
addition, a small but not insignificant subset of patients may
require implantation of a permanent pacemaker after valve
surgery.
Prognosis and survival
Serious long-term effects of aortic stenosis without timely
treatment include:
- congestive heart failure
- coronary heart disease
- enlargement of the left ventricle
- pulmonary edema
- sudden death
With surgery, the patient can expect to live a normal life
with necessary precautions as explained above.
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