Assessment of the St Jude Medical Portico Resheathable Aortic Valve System-Alternative Access (Portico ALT)

Inclusion Criteria:

1. Subject has provided written informed consent prior to uploading CT scan to core lab.
2. Subject is ≥ 18 years of age or legal age in host country.
3. Subject's aortic annulus diameter meets the range indicated in the Instructions for Use as measured by multislice CT conducted within 180 days prior to the index procedure.

4. Subject has senile degenerative aortic stenosis seen by echocardiography within 90 days of index procedure as measured by:

   1. mean gradient >40 mmHg
   2. Peak velocity ≥ 4.0 m/s
   3. Doppler Velocity Index <0.25
   4. Aortic valve area (AVA) of ≤ 1.0 cm2 or indexed EOA ≤ 0.6 cm2/m2).
5. Subject has symptomatic aortic stenosis as demonstrated by NYHA Functional Classification of Class II, or greater or other symptoms of aortic stenosis (e.g. syncope).

6. Subject is deemed high operable risk and preferred TAVI delivery route is alternate access (subclavian/axillary or direct aortic) per the medical opinion of the center's heart team and confirmed by SSC.

   • High risk is defined as an STS mortality > 8% or documented heart team agreement ≥ high risk for SAVR due to frailty or co-morbidities

Exclusion Criteria:

1. Subject is unwilling or unable to comply with all study-required follow-up evaluations.
2. Subject has a documented history of a cerebral vascular accident (CVA) or transient ischemic attack (TIA) within 6 months (less than or equal to 180 days) prior to the index procedure.
3. Subject has carotid artery disease requiring intervention.
4. Subject has evidence of a myocardial infarction (MI) within 30 days prior to patient index procedure.
5. Subject has a native aortic valve that is congenitally unicuspid, bicuspid, quadricuspid or non-calcified as seen by echocardiography.
6. Subject has severe mitral valvular regurgitation.
7. Subject has severe mitral stenosis.
8. Subject has a pre-existing prosthetic cardiac device, valve, or prosthetic ring in any position.
9. Subject refuses any blood product transfusion.
10. Subject has resting left ventricular ejection fraction (LVEF) less than 20%.
11. Subject has documented, untreated symptomatic coronary artery disease (CAD) requiring revascularization.
12. Subject has had a percutaneous interventional or other invasive cardiovascular or peripheral vascular procedure less than or equal to 14 days prior to index procedure.
13. Subject has severe basal septal hypertrophy that would interfere with transcatheter aortic valve placement.
14. Subject has a history of, or is currently diagnosed with, endocarditis.
15. There is imaging evidence of intracardiac mass, thrombus, or vegetation.
16. Subject is considered hemodynamically unstable (requiring inotropic support or mechanical heart assistance).
17. Subject is in acute pulmonary edema or requiring intravenous diuretic therapy to stabilize heart failure.
18. Subject with severe pulmonary disease as determined by STS score.
19. Subject is on chronic oral steroid therapy.
20. Subject has a documented hypersensitivity or contraindication to anticoagulant or antiplatelet medication.
21. Subject has renal insufficiency as evidenced by a serum creatinine greater than 3.0 mg/dL (265.5 µmol/L) or end-stage renal disease requiring chronic dialysis.
22. Subject has morbid obesity defined as a BMI greater than or equal to 40.
23. Subject has ongoing infection or sepsis.
24. Subject has uncontrolled blood dyscrasias as defined: leukopenia (WBC<3000 mm3), acute anemia (Hb<9 mg/dL), thrombocytopenia (platelet count <50,000 cells/mm3,).
25. Anatomy falling outside the recommended values in the IFU, unless specifically approved by the Subject Selection Committee.
26. Subject has an active peptic ulcer or has had gastrointestinal (GI) bleeding within 90 days prior to the index procedure.
27. Subject is currently participating in another investigational drug or device study, unless approved by the Sponsor.
28. Subject has/had emergency surgery for any reason within 30 days of the index procedure.
29. Subject has a life expectancy less than 1 year.
30. Subject has other medical, social or psychological conditions that, in the opinion of the Principal Investigator or the Subject Selection Committee, preclude the subject from study participation.
31. Subject is diagnosed with a state of dementia which would fundamentally complicate rehabilitation from the procedure or compliance with follow-up visits.
32. Subject has a documented allergy to contrast media that cannot adequately be treated, nitinol alloys, porcine tissue, or bovine tissue.
33. Significant aortic disease including abdominal aortic or thoracic aneurysm defined as maximal luminal diameter 5cm or greater
34. Subjects with severe pulmonary hypertension and severe RV dysfunction
35. Subjects with hypertrophic cardiomyopathy

Transaortic Subject Cohort Specific Exclusion Criteria

Subjects are not eligible for participation in the TAo access arm if they meet any of the following exclusion criteria:

1. Subject has a chest condition (anatomical or otherwise) that prevents TAo access.
2. Subject has pre-existing patent RIMA graft that would preclude access.
3. Subject has a porcelain aorta, defined as an extensive circumferential calcification of the ascending aorta that would complicate TAo access.

Subclavian/Axillary Subject Cohort Specific Exclusion Criteria

Subjects are not eligible for participation in the subclavian/axillary access arm if they meet any of the following exclusion criteria:

1. Subject's access vessel (subclavian/axillary) diameter will not allow for introduction of the 18/19 Fr delivery system.
2. Subject's subclavian/axillary arteries have severe calcification and/or tortuosity.
3. Subject has a history of LIMA/RIMA graft that would preclude access