Long-Term Clinical and Hemodynamic Performance of the Hancock II Versus the Perimount Aortic Bioprostheses
Bibliographic record
Abstract
BACKGROUND: The Medtronic Hancock II and the Carpentier-Edwards Perimount are among the world's most commonly used aortic bioprostheses. However, a direct comparison of their clinical performance is lacking. To minimize biases inherent to between-center comparisons, we examined these prostheses within a large, contemporary, single-center cohort. METHODS AND RESULTS: Between 1990 and 2007, 1659 patients (mean age, 73.1±9.3 years) underwent aortic valve replacement with either the Hancock II (N=1021) or the Perimount (N=638). Patients were prospectively followed-up with serial clinic visits and echocardiograms for up to 16 years (mean, 5.0±3.3 years). There was no significant difference in aortic root size preoperatively (P=0.7). Aortic root enlargement was more commonly performed with the Perimount (P<0.001), and the manufacturer valve size of the implanted prosthesis was larger with the Hancock II (P<0.001). Postoperatively, peak and mean transprosthesis gradients were higher for the Hancock II (32.7±0.7 and 16.0±0.3 mm Hg, respectively) than for the Perimount (24.9±0.7 and 13.4±0.4 mm Hg, respectively; P<0.001). However, no difference in left ventricular mass regression was observed at late follow-up (P=0.9). Unadjusted 10-year survival was 59.4%±2.4% for the Hancock II and 70.2%±3.8% for the Perimount (P=0.07). Multivariable predictors of survival did not include prosthesis type (P=0.2). CONCLUSIONS: For the same manufacturer valve size, the Perimount is larger, which may warrant enlarging the aortic root more often, and it is associated with better hemodynamics than the Hancock II. These differences do not impact survival or left ventricular mass regression, and the long-term clinical performances of the Hancock II and Perimount bioprostheses are equivalent.
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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 | 0.002 | 0.004 |
| 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 | 0.001 | 0.001 |
| 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".