Transcatheter aortic valve replacement (TAVR) has revolutionized the treatment of patients with aortic valve disease. TAVR is a less invasive treatment compared to the conventional surgical approach through median sternotomy. Patients selected for this procedure often have a profile associated with multiple comorbidities which predispose them to certain complications. TAVI procedures were initially performed under general anesthesia. However, due to improved procedure times and anesthetic techniques, sedation has become the current trend to preform them. When sedation for these procedures requires deep planes, hypoxia is more likely to occur due to respiratory depression, apnea, or airway obstruction. This is even more common in TAVR patients population, as obesity, sleep apnea, elevated ASA classification, advanced age, and combined cardiorespiratory disease are highly prevalent. For all these reasons, TAVR constitutes a risky procedure, presenting a profile of patients undergoing this procedure that can also be considered high risk. The provision of supplemental oxygen through nasal cannulae or face masks can prevent the development of hypoxia. Unfortunately, non-humidified nasal oxygen cannot exceed 2-5 L/min without causing damage to the nasal mucosa, and the percentage of oxygen delivered through variable-flow face masks is unpredictable. On the other hand, high-flow nasal oxygen therapy (HFNO) can provide humidified gas flow rates of up to 70 L/min through specially adapted nasal cannulae and reliably deliver oxygen concentrations between 21% and 100%. The use of HFNC could be justified in this context and could improve the outcomes and safety of these procedures, increasing oxygen content and minimizing hypercapnia. The study's hypothesis is HFNO will prevent hypoxemia and control hypercapnia during sedation for transcatheter aortic valve implantation (TAVI) better than conventional oxygen theraphy. Clinical and serological biomarkers of tissue injury will decrease with the use of HFNO. Clinical complications will decrease with the use of HFNO. The study population would be all patients \>18 years of age undergoing TAVI procedure and who agree to participate in the study in 8 centers in Barcelona.