Aortic stenosis surgery indications


 * Associate Editor-In-Chief: Mohammed A. Sbeih, M.D. [mailto:msbeih@perfuse.org]

Overview
Aortic stenosis requires aortic valve replacement if medical management does not successfully control symptoms. According to a prospective, single-center, nonrandomized study of 25 patients, percutaneous implantation of an aortic valve prosthesis in high risk patients with aortic stenosis results in marked hemodynamic and clinical improvement when successfully completed.

Indications
Aortic valve replacement is indicated in the following situations:
 * If the patient has symptoms due to aortic stenosis, such as angina, dizziness, syncope, dyspnea or heart failure symptoms . Average survival after the onset of these symptoms is around two to three years . With the presence of symptoms; the patient may be at risk for sudden death.
 * Severe oartic stenosis (valve area < 1.0 cm2, or the aortic jet velocity is over 4.0 m/sec and the mean transvalvular gradient exceeds 40 mmHg) if the patient has symptoms, left ventricular dysfunction (ejection fraction < 50%) or undergoing coronary artery bypass grafting. Valve replacement should not be performed for isolated severe AS in asymptomatic patients.
 * Usually performed in patients with moderate AS with symptoms to improve symptoms and prolong life expectancy, or if the patient undergoing coronary artery bypass grafting or aortic root reconstruction surgery.

If there are no contraindications to anticoagulants, mechanical prostheses are preferred in patients < 65 years of age. If the patient > 65 years or has any contraindication to anticoagulants; then bioprosetheses are preferred (biologic valve).

Age is not a contraindication to aortic valve replacement in aortic stenosis.

Low Flow Aortic Stenosis
If there is a decline in left ventricular function due to systolic dysfunction, there may be only a moderate transvalvular gradient or low flow aortic stenosis. If there is fibrosis of the left ventricle, there may be incomplete recovery after aortic valve replacement. This scenario can also occur among patients in whom there is a history of myocardial infarction: there is insufficient contractility to mount an aortic gradient.

Definition

 * 1) An aortic valve areas < 1.0 cm2
 * 2) A left ventricular ejection fraction < 40%
 * 3) A mean pressure difference or gradient across the aortic valve of < 30 mm Hg

With a dobutamine infusion, the aortic valve area should increase to > 1.2 cm2, and the mean pressure gradient should rise above 30 mm Hg. If there is a failure to acheive these improvements, early surgical mortality is 32-33%, but it is only 5–7% in those patients who can augment their contractility and gradient. Survival at five years was 88% after surgery if the patient can augment their contractility, but only 10–25% if the patient cannot augment their contractility.

It should be noted that left ventricular contractile reserve is a better predictor of surgical outcomes than markers of stenosis. Aortic valve surgery is indicated if there is severe AS along with an increase in the systolic velocity integral by >20% during a dobutamine infusion.

==ACC/AHA Guidelines- Indications for Aortic Valve Replacement (AVR) for Aortic Stenosis (DO NOT EDIT) == {{cquote|

Class I
1. AVR is indicated for symptomatic patients with severe AS. (Level of Evidence: B)

2. AVR is indicated for patients with severe AS undergoing coronary artery bypass graft surgery (CABG). (Level of Evidence: C)

3. AVR is indicated for patients with severe AS undergoing surgery on the aorta or other heart valves. (Level of Evidence: C)

4. AVR is recommended for patients with severe AS* and LV systolic dysfunction (ejection fraction less than 0.50). (Level of Evidence: C)

Class IIa
1. AVR is reasonable for patients with moderate AS undergoing CABG or surgery on the aorta or other heart valves (see Section 3.7 on combined multiple valve disease and Section 10.4 on AVR in patients undergoing CABG). (Level of Evidence: B)

Class IIb
1. AVR may be considered for asymptomatic patients with severe AS and abnormal response to exercise (e.g., development of symptoms or asymptomatic hypotension). (Level of Evidence: C)

2. AVR may be considered for adults with severe asymptomatic AS if there is a high likelihood of rapid progression (age, calcification, and CAD) or if surgery might be delayed at the time of symptom onset. (Level of Evidence: C)

3. AVR may be considered in patients undergoing CABG who have mild AS when there is evidence, such as moderate to severe valve calcification, that progression may be rapid. (Level of Evidence: C)

4. AVR may be considered for asymptomatic patients with extremely severe AS (aortic valve area less than 0.6 cm2, mean gradient greater than 60 mm Hg, and jet velocity greater than 5.0 m per second) when the patient’s expected operative mortality is 1.0% or less. (Level of Evidence: C)

Class III
1. AVR is not useful for the prevention of sudden death in asymptomatic patients with AS who have none of the findings listed under the Class IIa/IIb recommendations. (Level of Evidence: B)}}