Current balloon‐expandable transcatheter heart valve and delivery systems
Bibliographic record
Abstract
OBJECTIVES: Transcatheter valve and valve delivery systems are undergoing rapid evolution. We describe the current generation balloon-expandable valve and delivery systems. BACKGROUND AND METHODS: The SAPIEN XT valve represents the newest generation balloon-expandable aortic bioprosthesis. A cobalt-chromium alloy frame and additional design modifications facilitate a reduction in delivery profile while maintaining structural integrity, hemodynamics, and durability. The RetroFlex 3 delivery system represents the latest clinically available delivery system. It incorporates a fixed, tapered, and deflecting crossing tip to facilitate atraumatic introduction and a rapid inflation lumen to reduce valve motion during deployment. The NovaFlex delivery system represents the next generation delivery catheter. When used in conjunction with the SAPIEN XT valve and a specially constructed introducer sheath the inner and the outer diameters are 18 and 21 F, respectively. RESULTS: The RetroFlex 3 delivery system was utilized in nine patients and the NovaFlex delivery system in four. The valve implanted was the SAPIEN in six and the SAPIEN XT valve in seven. Implantation was successful in all patients. A reduction in device movement during balloon deployment was apparent as compared with earlier delivery systems. Aortic mean gradient fell from 45.6 (+/-15.1) mm Hg to 13.2 (+/-5.1) mm Hg, valve area rose from 0.68 (+/-0.19) to 1.5 (+/-0.28) cm(2). No patient had more than mild paravalvular regurgitation. CONCLUSION: Transcatheter valves and delivery systems continue to improve in terms of profile and ease of use.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.006 |
| 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) | 0.000 | 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 teacher head, 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".