The aim is to assess the response of cardiac output and stroke volume to volume preload optimization in patients with severe aortic stenosis treated with aortic prosthesis implantation.

Patients with severe aortic stenosis present a maintained overload pressure of the left ventricle that can lead to a progressive hypertrophy. This results in elevated left-sided filling pressures and impaired diastolic function.In this context, paradoxical changes in left ventricular function after aortic valve replacement have been described, with acute decrease of the afterload condition that can result in the development of a dynamic intraventricular gradient, especially in the presence of small ventricles with severe hypertrophy, resulting in hemodynamic collapse.

In this setting, it is particularly important to ensure accurate left ventricular preload to optimize myocardial contractility and guarantee an adequate hemodynamic response to valve implantation.

Patients with severe aortic stenosis submitted for transfemoral TAVI on spontaneous breathing will be randomly assigned 1:1 to standard care vs volume preload optimization. Non-invasive continuous monitoring (Clear Sight System, Edwards Lifesciences) will be used to evaluate the cardiac output and the stroke volume in both groups, comparing the hemodynamics before and after valve implant.

Inclusion Criteria:

• Aortic valve stenosis with echocardiographic derived criteria: mean gradient >40 mmHg or jet velocity greater than 4.0 m/s or an initial aortic valve area of < 0.8 cm2

Exclusion Criteria:

• Cardiogenic shock.
• Life expectancy < 1 year.
• Need of mechanic ventilation.

At recruitment and after study conclusion