Echocardiography Guided TAVR (Echo TAVR)

Inclusion Criteria: 1. symptomatic severe AS determined by echocardiography and Doppler that requiring aortic valve replacement, which is defined as: mean gradient ≥40 mmHg, peak aortic velocity ≥4 m/s, and aortic valve area (AVA) ≤1 cm2 (or an indexed AVA ≤0.6 cm2/m2); 2. a history of malignancy or a high familial risk of cancer, with refusal to undergo contrast- or radiation-guided procedures; 3. chronic kidney disease and refuse to receive contrast agents or radiation exposure. Exclusion Criteria: Required hybrid procedures or concomitant interventions on other cardiac malformations; Deemed inoperable due to extremely high surgical risk or severe comorbidities; Had untreated clinically significant coronary vascular disease amenable to revascularization; Previously undergone aortic valve replacement.