A Direct In Vitro Comparison of the Edwards SAPIEN and Medtronic CoreValve Transcatheter Aortic Valve implantation (TAVI) Devices and a Surgical Counterpart
Bibliographic record
Abstract
OBJECTIVE: The Edwards SAPIEN and the Medtronic CoreValve are the only commercially available devices suitable for transcatheter aortic valve implantation (TAVI). Though their clinical results are continuously updated, there are no direct comparisons reported for their hydrodynamic performance, or with equivalent surgical solutions. This study is mainly targeted at providing, for the first time, a direct in vitro comparison of the performances of the SAPIEN and CoreValve devices; and an insight on the different operative mechanisms of TAVI devices and their surgical counterparts. METHODS: The two transcatheter valves (size 26 mm for both the SAPIEN and the CoreValve) and an equivalent surgical bioprosthesis (Sorin Pericarbon) were assessed conforming the requirements of the standard ISO 5840:2009, on a hydro-mechanical cardiovascular pulse duplicator system (Vivitro Superpump SP3891, Vivitro, BC, Canada). The TAVI devices were mounted on a silicone mock aortic root, including three rubber leaflets in order to replicate the presence of the native valve during the tests. The silicone leaflets were removed to test the surgical valve and the suture ring of the prosthesis was sealed to the annulus region. The cardiac chambers’ pressures and aortic flow were measured and the valve performances were compared in terms of mean transvalvular systolic pressure drop (ΔP), regurgitant volumes, effective orifice area (EOA) and fluid-mechanical left ventricular energy loss. RESULTS: The CoreValve performance in terms of ΔP and EOA, closing regurgitation and energy loss was slightly better than that of the SAPIEN. Both TAVI devices were characterized by significantly lower ΔP values compared to the surgical counterpart, but they resulted affected by considerably higher levels of paravalvular leakage (see figure). This rendered the overall performance of the surgical valve more efficient at low cardiac outputs (COs), while the transcatheter valves performed better at higher flow rates. CONCLUSIONS: Globally, the transcatheter and surgical valve performances were comparable, with the TAVI devices being superior at high physiological values of the cardiac output, and the surgical valve at low flow rates.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".