Hemodynamic performance on exercise: comparison of a stentless and stented biological aortic valve replacement.
Bibliographic record
Abstract
BACKGROUND AND AIM OF THE STUDY: Although stentless valves are expected to be hemodynamically superior to stented valves, the results of comparative trials have been inconsistent. The study aim was to compare hemodynamic function at rest and on exercise in 50 stentless and stented biological replacement aortic valves METHODS: Twenty-one patients with a Toronto stentless porcine valve and 29 with a Perimount stented bovine pericardial valve were exercised using a bicycle ergometer. Echocardiography was performed before, and during exercise testing. RESULTS: Patients with either valve type were exercised to a similar degree. Transaortic resistance was slightly lower in the Perimount compared with the Toronto at rest (p = 0.03) and at peak exercise (p = 0.04), and flow was higher in the Perimount at rest (p = 0.007), but not at peak exercise. There were no significant differences between the valve types in peak velocity, mean pressure difference or effective orifice area either at rest or on peak exercise. CONCLUSION: There were no clinically significant differences in hemodynamic function between the stented and stentless biological valves chosen for comparison either at rest or during bicycle exercise.
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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) | 0.000 | 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".