The Toronto root stentless valve in the subcoronary position is hemodynamically superior to the mosaic stented completely supra-annular bioprosthesis.
Bibliographic record
Abstract
BACKGROUND AND AIM OF THE STUDY: Stentless valves are considered to exhibit better hemodynamics after aortic valve replacement (AVR) compared to stented valves. However, a new generation of stented bioprostheses for completely supra-annular implantation has been designed to optimize the ratio of the effective orifice area (EOA) of the prosthesis and aortic annulus area. The study aim was to determine whether a stentless valve implanted in the subcoronary technique renders larger orifice areas and lower transvalvular pressure gradients at rest and exercise compared to a completely supra-annular stented device. METHODS: Twenty patients underwent AVR for aortic stenosis with the St. Jude Medical (SJM) Toronto Root stentless porcine bioprosthesis, using a subcoronary implantation technique. Through the authors' institutional database, 20 additional patients were identified who had undergone AVR with the Medtronic Mosaic stented completely supra-annular porcine bioprosthesis. The patient groups were not matched for labeled valve size, but for annulus diameter measured intraoperatively using Hegar's dilators. Hemodynamic performance was assessed by transthoracic echocardiography at discharge (early) and by rest and stress echocardiography at six months postoperatively (mid-term). RESULTS: Transvalvular mean pressure gradients (MPG) at rest were significantly lower in the stentless group, but cardiac output was similar in both groups. Stress echocardiography also revealed significantly lower gradients at 25 W and 50 W exercise in the stentless group. The EOA index (EOAI), grouped by annulus diameter, tended to be larger in the stentless group and showed no severe patient-prosthesis mismatch (PPM; EOAI <0.65 cm2/m2) which, in contrast, occurred in three patients (15%) in the stented group (p = 0.072). CONCLUSION: In summary, the SJM Toronto Root porcine stentless bioprosthesis in the subcoronary position showed lower MPGs and larger EOAs at rest and during exercise compared to the Medtronic Mosaic porcine stented bioprosthesis. Therefore, physically active patients in particular may benefit from use of the stentless valve. Because of its larger EOA, a stentless valve should be implanted if severe PPM is expected.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".