This study will evaluate the safety and effectiveness of the Edwards SAPIEN 3/SAPIEN 3 Ultra Transcatheter Heart Valve (THV) compared with clinical surveillance (CS) in asymptomatic patients with severe, calcific aortic stenosis.

This is a prospective, randomized, controlled, multicenter study. Patients will be randomized to receive either transcatheter aortic valve replacement (TAVR) with the Edwards SAPIEN 3 / SAPIEN 3 Ultra THV or clinical surveillance. Patients will be stratified by whether they are able to perform a treadmill stress test. Patients who have a positive stress test will be followed in a registry to collect data on subsequent treatment and mortality, as applicable.

Inclusion Criteria:

1. 65 years of age or older
2. Severe aortic stenosis
3. Patient is asymptomatic
4. LV ejection fraction ≥ 50%
5. Society of Thoracic Surgeons (STS) risk score ≤ 10
6. The study patient has been informed of the nature of the study, agrees to its provisions and has provided written informed consent.

Exclusion Criteria:

1. Patient is symptomatic
2. Patient has any concomitant valvular, aortic, coronary artery disease requiring surgery making AVR a Class I indication.
3. Native aortic annulus size unsuitable for sizes 20, 23, 26, or 29 mm THV
4. Iliofemoral vessel characteristics that would preclude safe placement of the introducer sheath.
5. Left ventricular outflow tract calcification that would increase the risk of annular rupture or significant paravalvular leak post TAVR
6. Evidence of an acute myocardial infarction ≤ 30 days before randomization
7. Aortic valve is unicuspid, bicuspid with unfavorable features for TAVR, or is non-calcified
8. Severe aortic regurgitation (>3+)
9. Severe mitral regurgitation (>3+) or ≥ moderate mitral stenosis
10. Pre-existing mechanical or bioprosthetic valve in any position
11. Symptomatic carotid or vertebral artery disease or successful treatment of carotid stenosis within 30 days of randomization
12. Leukopenia, anemia, thrombocytopenia, history of bleeding diathesis or coagulopathy, or hypercoagulable states
13. Hemodynamic or respiratory instability requiring inotropic support, mechanical ventilation or mechanical heart assistance within 30 days of randomization
14. Hypertrophic cardiomyopathy with obstruction
15. Cardiac imaging evidence of intracardiac mass, thrombus or vegetation
16. Inability to tolerate or condition precluding treatment with anti-thrombotic therapy
17. Stroke or transient ischemic attack within 90 days of randomization
18. Renal insufficiency and/or renal replacement therapy
19. Active bacterial endocarditis within 180 days of randomization
20. Severe lung disease or currently on home oxygen
21. Severe pulmonary hypertension
22. History of cirrhosis or any active liver disease
23. Significant frailty as determined by the Heart Team
24. Significant abdominal or thoracic aortic disease that would preclude safe passage of the delivery system
25. Patient refuses blood products
26. BMI >50 kg/m2
27. Estimated life expectancy <24 months
28. Absolute contraindications or allergy to iodinated contrast that cannot be adequately treated with pre-medication
29. Currently participating in an investigational drug or another device study.
30. Active SARS-CoV-2 infection (Coronavirus-19 [COVID-19]) or previously diagnosed with COVID-19 with sequelae that could confound endpoint assessments