Medium to long-term clinical outcome following stentless aortic valve replacement: comparison between allograft and xenograft valves
Bibliographic record
Abstract
The xenograft stentless valve was designed to emulate the haemodynamic performance of the allograft. Early outcomes using either surgical option (stentless xenograft valve or allograft) have been similar. However, follow-up outcomes remain to be compared. Between 1st January 1991 and 1st January 2001, 415 patients underwent aortic valve replacement. Two hundred and seventeen patients received an allograft and in 198 patients a Toronto stentless porcine valve (TSPV) was implanted. Mean time to follow-up was 6.3+/-4.4 years. Ten years freedom from structural valve deterioration (SVD) (TSPV 86+/-5%, allograft 82+/-5%, P=0.49) and freedom from reoperation (RE) (TSPV 80+/-4% vs. allograft 85+/-4%, P=0.61) were not significantly different. The TSPV was associated with significantly worse actuarial survival than the homograft (TSPV 40+/-4% vs. homograft 55+/-4%, P=0.02). However, after adjustment for other variables using a multivariate model, TSPV use was not an independent predictor of impaired late survival (LS) (P=0.44). Kaplan-Meier analysis in a subgroup of patients aged 45-65 years comparing LS, RE and SVD between xenografts and allografts identified similar results. The porcine stentless valve may be associated with similar clinical performance to the allograft over the medium to long-term.
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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 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".