Transcatheter Aortic Valve Implantation Versus Standard Surgical Aortic Valve Replacement

Transcatheter Aortic Valve Implantation Versus Standard Surgical Aortic Valve Operation for Aortic-Valve Stenosis in Patients at Risk to Severe Valve Obstruction.

The mechanical intervention is treating aortic valve stenosis (AVS) which may be performed using the standard open surgical approach for aortic valve replacement (AVR) or transcatheter aortic valve implantation (TAVI). The key question of this study is to establish the difference in all-cause and cause-specific (cardiac vs noncardiac) mortality, all hospitalizations for heart failure within 24 months of follow-up, left ventricular reverse remodeling after adjustment for death, as assessed by means of the left ventricular end-diastolic volume (LVEDV), in patients who received the TAVI vs the standard surgical procedure for AVS. Any potential failure of the devices in question will be thoroughly investigated by means of CT scanning and biomechanical computational modelling, utilising finite element analysis (FEA).

The target population enrolled in the study includes patients with aortic-valve stenosis at risk to severe valve obstruction who have had TAVI or standard surgical procedure of their aortic valve with or without coronary artery by pass grafting (CABG) or percutaneous coronary intervention (PCI). Individuals were adequately treated per applicable standards, including for coronary artery disease (CAD), left ventricular (LV) dysfunction, AVS, and heart failure (HF). Patients enrolled in the studies were New York Heart Association (NYHA) functional class II, III, or outpatient NYHA IV.

Three groups of patients are included in the study. Patients who were managed with TAVI, patients who received AVR with conventional stented xenograft and recipients of AVR undergoing surgery with the use of sutureless aortic valve.

we calculated that a total of 649 patients per group would be needed for 90% power to show an absolute between-groups difference of 10% in the primary outcome at a two-sided alpha level of 0.02 (corrected alpha level to take into account multiple comparison between 3 groups). In this exhaustive study between 2011 and 2021, we hope to include a total of 6700 patients (2800 in the TAVI group, 3200 patients who received AVR with conventional stented xenograft and 700 patients with the use of sutureless aortic valve).

Two supplementary studies will be conducted. The study will concentrate on the CT scan evaluation of potential morphological and functional alterations in the aortic root following implantation of the respective devices, incorporating a comparative analysis. The second study will concentrate on the biomechanics of the implanted device and potential failure, using a finite element analysis investigation.

Inclusion Criteria:

• Individuals enrolled in TAVI arm were required to have the predicted risk of operative mortality was ≥ 15% and/or a STS score of ≥ 10. A candidate who did not meet the STS score criteria of ≥ 10 was included in the study if a peer review by at least two surgeon investigators concluded and documented that the patient's predicted risk of operative mortality was ≥ 15%. For all group Senile degenerative aortic valve stenosis with echocardiography derived criteria: mean gradient > 40 mm Hg or jet velocity > 4.0 m/s or an aortic valve area (AVA) of < 0.8 cm2 (or AVA index < 0.5 cm2/m2).

Exclusion Criteria:

• • Patients with evidence of an acute myocardial infarction ≤ 1 month before the intended treatment (defined as Q wave MI, or non-Q wave MI with total CK elevation ≥ twice normal in the presence of CK-MB elevation and/or troponin level elevation.

  • Blood dyscrasias as defined : leukopenia (WBC < 3000 mm3), acute anemia (Hb < 9 mg%), thrombocytopenia (platelet count < 50,000 cells/mm³), history of bleeding diathesis or coagulopathy.
  • Hemodynamic instability requiring inotropic therapy or mechanical hemodynamic support devices
  • Need for emergency surgery for any reason.
  • Hypertrophic cardiomyopathy with or without obstruction.
  • Severe ventricular dysfunction with LVEF < 20%.
  • Echocardiographic evidence of intracardiac mass, thrombus or vegetation.
  • Active peptic ulcer or upper gastro-intestinal bleeding within the prior 3 months.
  • A known hypersensitivity or contraindication to aspirin, heparin, ticlopidine (Ticlid), or clopidogrel
  • (Plavix), or sensitivity to contrast media, which cannot be adequately pre-medicated.
  • For TAVI arm Native aortic annulus size < 18mm or 25mm as measured by echocardiogram.
  • Subject was offered surgery but refused surgery.
  • Recent (within 6 months) cerebrovascular accident or transient ischemic attack.
  • Renal insufficiency (creatinine > 3.0mg/dL) and/or end stage renal disease requiring chronic
  • dialysis.
  • Life expectancy < 12 months due to non-cardiac co-morbid conditions.
  • For TAVI group significant abdominal or thoracic aorta disease, including aneurysm (defined as maximal luminal diameter 5 cm or greater), marked tortuosity, aortic arch atheroma, narrowing of the abdominal aorta with particular regard for calcification and surface irregularities, or severe "unfolding" and tortuosity of the thoracic aorta. This criteria were applicable for transfemoral patients only.
  • For TAVI group Iliofemoral vessel characteristics that would preclude safe placement of 14F or 18F introducer
  • For TAVI arm sheath such as severe calcification, severe tortuosity or vessels size diameter < 7 mm for 22F
  • Active bacterial endocarditis or other active infections.
  • For TAVI arm bulky calcified aortic valve leaflets in close proximity to coronary ostia.