No recruitment

To assess the ability of baseline clinical parameters and imaging modalities to predict short and long term left ventricular function and clinical outcome of subjects with low-gradient, severe aortic stenosis.

To assess the impact of aortic valve replacement as compared to medical therapy on clinical outcome of patients with low-gradient, severe aortic stenosis.

To assess possible impact of aortic annulus assessment using 3-dimensional imaging modalities on the assessment of AS severity and definition of low gradient severe aortic stenosis.

To assess the ability of baseline clinical parameters and imaging modalities to predict short and long term left ventricular function and clinical outcome of subjects with impaired left ventricular function and / or low-gradient, severe aortic stenosis.

To assess the impact of aortic valve replacement as compared to medical therapy on clinical outcome of patients with impaired left ventricular function and / or low-gradient, severe aortic stenosis.

To assess possible impact of aortic annulus assessment using 3-dimensional imaging modalities on the assessment of AS severity and definition of low gradient severe aortic stenosis.

Inclusion Criteria:

1. Severe aortic stenosis defined as aortic valve area of less than 1 cm2 or index area of 0.6 cm2/m2 and low gradient (mean gradient across the aortic valve <40 mmHg) by echocardiography
2. Symptomatic patients with aortic stenosis referred for medically indicated AVR
3. Signed informed consent to participate in the study.

Exclusion Criteria:

1. Pregnancy or breast feeding (women of childbearing potential will have a serum or urine pregnancy test).
2. Need for emergency surgery for any reason.
3. Any case in which the practicing physician asserts that enrollment in the protocol will adversely affect the patient treatment course.

Subjects with severe symptomatic aortic stenosis defined as aortic valve area of less than 1 cm2 or index area of 0.6 cm2/m2 by echocardiography, together with low-gradient (mean gradient across the aortic valve <40 mmHg) who are referred for treatment of AS will be recruited. A total of up to 100 consecutive subjects of both genders will be enrolled at the Sheba Medical Center. The study procedures, clinical management and follow up will be done at the Sheba Medical Center.