The Valvuloplasty Scoring Balloon First-in-Man study is a prospective, single arm, two phase, observational registry to demonstrate the safety and efficacy of the Valvuloplasty Scoring Balloon Catheter for the treatment of critical aortic valve stenosis.

Phase 1 will enroll patient who are scheduled to undergo open surgical aortic valve replacement and will have the Valvuloplasty Scoring Balloon delivered to their stenotic aortic valve through a standard aortotomy and deployed immediately prior to valve replacement.

Phase 2 will enroll patients with aortic valve stenosis who are deemed to not be suitable candidates for elective surgical aortic valve replacement and in whom the investigational Valvuloplasty Scoring Balloon will be used as a stand-alone Valvuloplasty procedure or "bridge" to trans-catheter aortic valve implantation (TAVI) or surgery.

Inclusion Criteria:

• Native, degenerative-calcific, tricuspid, aortic valve stenosis with echocardiographic derived criteria: mean gradient of >40 mm Hg or Doppler peak systolic velocity greater than 4.0 m/s or an initial aortic valve area < 0.8 cm2.
• Symptomatic aortic valve disease as demonstrated by CCS Functional Class II or greater
• Aortic valve annulus of greater than or equal to 18 mm and less than or equal to 28 mm measured on pre-procedure TTE.
• Phase 1 patients must be scheduled for a surgical aortic valve replacement.
• Phase 2 patients must not be suitable candidates for elective surgical aortic valve replacement.

Exclusion Criteria:

• Recent myocardial infarction (<30days)
• Unicuspid or bicuspid aortic valve or non-calcific aortic valve stenosis
• Any sepsis, including active endocarditis
• Concomitant 2+ or greater aortic valve valve regurgitation
• LVEF < 20%
• CVA or TIA within the previous 6 months
• Previous aortic valve replacement (bioprosthetic or mechanical)