Abstract 13341: Systolic Time Intervals and Alternative Echocardiographic Parameters to Evaluate Bioprosthetic Aortic Valve Function
Bibliographic record
Abstract
Background: Bioprosthesis (BP) used for aortic valve replacement (AVR) in aortic valve disease are subject to structural valve deterioration (SVD) after 20 years or less which leads to reintervention. The diagnostic of SVD can be challenging in the presence of patient-prosthesis mismatch (PPM) which occurs when the effective orifice area (EOA) of the BP is too small for the metabolic needs of a patient. Both SVD and PPM are mainly diagnosed with echocardiography and are characterized by high transprosthetic mean and peak pressure gradients (MG and PG) and maximal velocity (Vmax) as well as reduced EOA. Easily accessible parameters are needed to distinguish SVD from PPM. Acceleration time (AT), ejection time (ET) and AT/ET have been proposed as accurate to identify SVD in presence of PPM. However, these parameters need to be validated. Objectives: The main goal of the present study is to determine the accuracy of AT and AT/ET and to validate new echocardiographic parameters that can distinguish SVD from PPM. New parameters proposed for this study are MG/EOA and PG over mean flow rate (PG/MFR). Methods: In a retrospective study, we analyzed echocardiographic data of 653 patients who underwent AVR. PPM was defined as a projected EOA to body surface area inferior to 0.85 cm 2 /m 2 . SVD was defined using a multiparametric integrative approach including morphological (fibrocalcific remodeling, thickening and stiffening of valve leaflets) criteria and hemodynamic changes according to American Society of Echocardiography/European Association for Cardiovascular Imaging recommendations. Results: EOA was lower and MG higher for patients with SVD compared to those with pure PPM. PG/Q and MG/EOA were significantly higher in patients with SVD compared to patients presenting pure PPM (PG/MFR: 0.22 mm Hg/ml/s ± 0.01 vs 0.15 mm Hg/ml/s ± 0.01; MG/EOA: 31 mm Hg/cm 2 ±2 vs 16 mm Hg/cm 2 ±2, p<0.001) respectively. ROC analysis showed that PG/Q and MG/EOA were the best echocardiographic parameters to distinguish pure PPM from SVD with AUC of 0.872 and 0.876 respectively. AT and AT/ET achieved AUC of 0.682 and 0.663. Conclusion: AT and AT/ET are not accurate parameters to identify SVD in presence of PPM. MG/EOA and PG/MFR represent interesting alternatives to conventional parameters.
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".