<br>        Inclusion Criteria:<br><br>          1. The subject has an indication for treatment by valve replacement with a bioprosthesis<br>             according to the IFU, through either full sternotomy or mini-sternotomy.<br><br>          2. The subject has aortic valve disease that can be treated with a commercially available<br>             Perceval valve size, based on preoperative CT-scan.<br><br>          3. The subject has:<br><br>               1. critical aortic valve area defined as an initial aortic valve area of =1.0 cm2 or<br>                  aortic valve area index < 0.6 cm2/m2 AND<br><br>               2. Mean gradient > 40 mmHg or Vmax > 4 m/sec by resting echocardiogram or<br>                  simultaneous pressure recordings at cardiac catheterization [or with dobutamine<br>                  stress, if subject has a left ventricular ejection fraction (LVEF) <55%] or<br>                  velocity ratio < 0.25;<br><br>          4. The subject is symptomatic due to aortic stenosis with functional class of New York<br>             Heart Association (NYHA) II or higher.<br><br>          5. The subject has signed the informed consent.<br><br>          6. The subject is of legal minimum age.<br><br>          7. The subject will be available for postoperative follow-up beyond one year.<br><br>        Exclusion Criteria:<br><br>          1. The subject has a contraindication for treatment by the Perceval valve or by a<br>             bioprosthetic aortic valve as stated in the IFU.<br><br>          2. The subject has aneurismal dilation or dissection of the ascending aortic wall.<br><br>          3. The subject is scheduled for concomitant procedures other than Coronary Aortic Bypass<br>             Graft (CABG), myectomy with or without aortic annulus enlargement<br><br>          4. The subject has congenital bicuspid (i.e. Sievers type 0) or unicuspid aortic valve.<br><br>          5. Anatomical structures not suitable for Perceval valve such as: aortic root<br>             enlargement, where the ratio between the diameter of the sino-tubular junction and the<br>             annulus diameter is > 1.3.<br><br>          6. The subject has a prosthetic heart valve in any position, including mitral valve<br>             repair.<br><br>          7. The subject has a stroke or myocardial infarction (STEMI and NSTEMI) within 30 days<br>             prior to the planned valve implant surgery.<br><br>          8. The subject has active endocarditis, myocarditis, or sepsis.<br><br>          9. The subject is in cardiogenic shock manifested by low cardiac output and needing<br>             hemodynamic support.<br><br>         10. The subject is allergic to nickel alloys.<br><br>         11. The subject is already included in another clinical trial that could confound the<br>             results of this clinical investigation.<br>