Acute renal failure (ARF) after transcatheter aortic valve implantation (TAVI) is a frequent complication, with significant clinical consequences. History of chronic kidney disease and the use of a large amount of iodinated contrast for planning and procedure are among the main risk factors for the development of this complication. The present study aims to: (1) define the role of non-contrast imaging modalities in pre-procedure planning; (2) evaluate the feasibility and safety of a new TAVI technique without using iodinated contrast; (3) to determine the incidence of acute renal failure in patients with aortic stenosis and chronic kidney disease undergoing TAVI, using the new technique without contrast. The study will be divided into two stages. In the pilot phase, 25 consecutive patients with chronic kidney disease (stage ≥ 3a) will have the TAVI planning and procedure performed without the use of iodinated contrast, but with all the steps subjected to verification by the standard technique, to ensure the safety of the patient. The occurrence of the combined primary safety outcome composed of adverse clinical events within 30 days (defined by the VARC-2 criteria) in less than 20% of cases will be used to define the continuity of the study. In the second phase, 50 patients with chronic kidney disease stage ≥ 3b will be submitted to TAVI with the "zero contrast" technique. The primary outcome assessed at this stage of the study will be the incidence of AKI within 7 days after TAVI using the new technique in this high-risk population.

This will be a prospective, single-center, single-arm clinical trial, to be carried out at the Heart Institute of Hospital das Clínicas, Faculty of Medicine, University of São Paulo (InCor - HC - FMUSP). The study will be divided into two phases. The first phase ("pilot") will test the concept, feasibility and safety of using a "zero contrast" strategy to carry out the planning and procedure of TAVI through transfemoral access with the self-expanding bioprosthesis Evolut R / Pro in 25 consecutive patients with CKD. The second phase ("zero contrast") will include 50 patients with CKD who will be submitted to transfemoral TAVI with the Evolut R / Pro bioprosthesis using the "zero contrast" approach, seeking to evaluate the results of the procedure and the incidence of AKI with the new strategy.

Inclusion Criteria:

• Symptomatic patients with severe aortic valve stenosis (AoS).
• CKD in stage ≥3a (GFR <60mL / min / 1.73m2).
• Signature of the free and informed consent form (ICF).

Exclusion Criteria:

- Any condition considered a contraindication for the implantation of a biological valve prosthesis (for example, the patient has an indication for mechanical valve prosthesis).

• Hypersensitivity or known contraindication to any of the following items that cannot be adequately premedicated: aspirin, clopidogrel or heparin (HIT / HITTS) nitinol (titanium or nickel) the contrast medium (pilot phase)

• Blood dyscrasias: leukopenia (white blood cell count <1000 / mm3), thrombocytopenia (platelet count <50,000 cells / mm3), history of hemorrhagic diathesis, coagulopathy or hypercoagulable states.
• Active infection, including active endocarditis.
• Cardiogenic shock manifested by low cardiac output, dependence on vasopressors or mechanical hemodynamic support.
• Recent stroke (up to 2 months after heart-team evaluation) or transient ischemic attack.
• Gastrointestinal bleeding that prevents platelet anticoagulation or anti-aggregation.
• Refusal to transfuse blood.
• Severe dementia (resulting in the inability to provide informed consent for the study / procedure).
• Life expectancy estimated at less than 12 months.
• Other medical, social or psychological conditions that, in the investigator's opinion, prevent the patient from consenting or adhering adequately to the protocol.
• Pre-existing prosthetic heart valve in the aortic position.
• Presence of stenosis or significant mitral regurgitation.
• Presence of obstructive hypertrophic cardiomyopathy.
• Clinical indication for coronary angiography or percutaneous coronary intervention in the period including the previous 30 days and 30 days after the TAVI procedure. In this case, the use of contrast media for these procedures can be a confusing factor for the analysis of the primary study outcome.
• Contraindication for the transfemoral approach based on evaluation by non-contrast TCMS and by CO2 aortoiliac angiography (anatomical screening).
• High risk of rupture of the ring or significant residual paravalvular leak due to important calcification of the left ventricular outflow tract.
• High risk of coronary occlusion (height of the coronary ostium <10 mm with narrow SOV: <1 mm greater than the size of the bioprosthesis) defined by imaging methods.