Use of the Transcatheter Aortic Valve Replacement Surgical Assist System and its Disposable Kit in Patients With Severe Aortic Stenosis to Evaluate the Safety and Efficacy of the Transcatheter Aortic Valve Replacement Surgical Assist System and its Disposable Kit for Use as an Adjunct to Transcatheter Aortic Valve Replacement

Inclusion Criteria:

• Age ≥65 years old, gender is not limited;

• Patients assessed by a cardiac multidisciplinary team (MDT) expert panel as having severe aortic stenosis and suitable for transcatheter aortic valve replacement;

  *Severe aortic stenosis was defined as echocardiographically demonstrated transaortic valve flow velocity ≥4.0 m/s, or transaortic valve pressure differential ≥40 mmHg (1 mmHg=0.133 kPa), or aortic orifice area <1.0 cm2, or effective aortic orifice area index <0.6 cm2/m2; for low-pressure-differential-low-flow rate by dopa-phenobutylamine loading test, Doppler ultrasound evaluation or other imaging means of assessment for those judged to have severe aortic stenosis.

• Have a core laboratory assessment that the patient is anatomically suitable for transcatheter aortic valve replacement;

• Patients who understand the purpose of the trial, voluntarily participate in the trial, sign an informed consent form, and are willing to cooperate in the follow-up.

Exclusion Criteria:

• Patients whose access or aortic root anatomical pattern is unsuitable for TAVR treatment;
• Poor peripheral arterial conditions that preclude transfemoral TAVR;
• Aortic annulus horizontal pinch angle ≥65° as measured by preoperative MDCT;
• Patients at high risk of coronary obstruction requiring intraoperative coronary protection measures;
• Patients requiring intraoperative delivery with a grapple assist system;
• Previous implantation of a prosthetic aortic valve (bioprosthetic or mechanical);
• Active stage of infective endocarditis or other active infection;
• Combined mitral, tricuspid or severe macrovascular lesions requiring surgical or interventional intervention;
• Echocardiography suggestive of left ventricular thrombus, intracardiac mass or redundant organisms;
• Diagnosis of hypertrophic cardiomyopathy, restrictive cardiomyopathy, infiltrative cardiomyopathy (e.g. amyloidosis, haemochromatosis, nodular disease, etc.), constrictive pericarditis;
• Severe obstruction of the left ventricular outflow tract without corrective measures;
• Severe pulmonary hypertension (pulmonary artery systolic pressure >70 mmHg measured by ultrasound);
• Severe right heart dysfunction as suggested by a combined clinical and ultrasound assessment;
• Severe left heart systolic insufficiency (left ventricular ejection fraction <30%);
• Cardiogenic shock or haemodynamic instability requiring ventricular assist device therapy within 30 days prior to enrolment;
• End-stage heart failure (ACC/AHA Stage D), or post cardiac transplantation, or awaiting cardiac transplantation;
• Acute myocardial infarction within 30 days prior to enrolment;
• Has had a stroke within 3 months prior to enrolment;
• Stenosis of the common or internal carotid artery or vertebral artery (>70% stenosis) requiring treatment as recommended by the relevant disciplinary consultation;
• Severe cardiac and aortic disease requiring concomitant treatment, including ascending aortic aneurysm (maximum diameter ≥ 50 mm);
• Severe renal insufficiency (estimated glomerular filtration rate <30mL/min/1.73m2);
• Active peptic ulcer or history of upper gastrointestinal bleeding within 3 months prior to enrolment;
• Severe coagulopathy; Patients with known intolerance to anticoagulant, antiplatelet drugs or anaesthetic drugs; Patients who have participated in other drug or medical device clinical trials prior to enrolment that have not met the primary endpoint; Patients who, in the opinion of the investigator, are not suitable for participation in this clinical trial