Impact of implant depth on hydrodynamic function with the ACURATE <i>neo</i> transcatheter heart valve following valve-in-valve transcatheter aortic valve replacement in Mitroflow bioprosthetic valves: an ex vivo bench study
Bibliographic record
Abstract
AIMS: We aimed to assess the impact of implant depth on hydrodynamic function following valve-in-valve (VIV) transcatheter aortic valve replacement (TAVR) using the ACURATE neo transcatheter heart valve (THV) through an ex vivo bench study. METHODS AND RESULTS: Multiple implantation depths were tested at incremental depths of 2 mm using a small size ACURATE neo valve for VIV TAVR in 19 mm, 21 mm, 23 mm, and 25 mm Mitroflow bioprosthetic valves. Multimodality imaging and hydrodynamic evaluation was performed at each implantation depth. A low implantation was associated with higher transvalvular gradients. The highest transvalvular gradient was observed at -10 mm depth for 19 mm (40.0±0.5 mmHg), -8 mm for 21 mm (15.3±0.2 mmHg), -6 mm for 23 mm (14.7±0.3 mmHg) and -8 mm for 25 mm (8.4±0.2 mmHg) surgical valves. The lowest transvalvular gradient was observed at 0 mm depth for the 19 mm (14.9±0.2 mmHg)/21 mm (7.2±0.1 mmHg), and +2 mm depth for the 23 mm (5.7±0.1 mmHg)/25 mm (5.8±0.1 mmHg) surgical valves. At low implantation depth, there was worse leaflet pin-wheeling and also evidence of interaction of THV leaflets with those of the surgical valve that impaired leaflet coaptation, resulting in a high regurgitant fraction (42.5% in the 21 mm and 83.3% in the 23 mm surgical valve at -10 mm depths). CONCLUSIONS: A high implant is desirable to facilitate favourable hydrodynamic function when performing VIV TAVR using the ACURATE neo THV for Mitroflow aortic bioprostheses sized ±25 mm. In a 19 mm Mitroflow valve, positioning the upper crown of the ACURATE neo THV above the posts of the surgical valve is desirable to facilitate favourable transvalvular gradients. Low implantation results in higher transvalvular gradients and worse pin-wheeling, and THV leaflet dysfunction can be severe due to interaction with the surgical valve.
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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 | 0.001 | 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".