Inclusion Criteria:

1. The subject has an indication for treatment by valve replacement with a bioprosthesis according to the IFU, through either full sternotomy or mini-sternotomy.
2. The subject has aortic valve disease that can be treated with a commercially available Perceval valve size, based on preoperative CT-scan.
3. The subject has: a) critical aortic valve area defined as an initial aortic valve area of ≤1.0 cm2 or aortic valve area index < 0.6 cm2/m2 AND b) Mean gradient > 40mmHg or Vmax > 4m/sec by resting echocardiogram or simultaneous pressure recordings at cardiac catheterization [or with dobutamine stress, if subject has a left ventricular ejection fraction (LVEF) <55%] or velocity ratio < 0.25;
4. The subject is symptomatic due to aortic stenosis with functional class of NYHA II or higher.
5. The subject has signed the informed consent.
6. The subject is of legal minimum age.
7. The subject will be available for postoperative follow-up beyond one year.

Exclusion Criteria:

1. The subject has a contraindication for treatment by the Perceval valve or by a bioprosthetic aortic valve as stated in the IFU.
2. The subject has aneurismal dilation or dissection of the ascending aortic wall.
3. The subject is scheduled for concomitant procedures other than CABG, myectomy with or without aortic annulus enlargement
4. The subject has congenital bicuspid (i.e. Sievers type 0) or unicuspid aortic valve.
5. Anatomical structures not suitable for Perceval valve such as: aortic root enlargement, where the ratio between the diameter of the sino-tubular junction and the annulus diameter is > 1.3.
6. The subject has a prosthetic heart valve in any position, including mitral valve repair.
7. The subject has a stroke or myocardial infarction (STEMI and NSTEMI) within 30 days prior to the planned valve implant surgery.
8. The subject has active endocarditis, myocarditis, or sepsis. 
9. The subject is in cardiogenic shock manifested by low cardiac output and needing hemodynamic support.
10. The subject is allergic to nickel alloys.
11. The subject is already included in another clinical trial that could confound the results of this clinical investigation.