Abstract 15457: Novel Three-dimensional Principal Strain Analysis for Global Function of Right Ventricle After Repair of Tetralogy of Fallot. Can It Predict Need for Pulmonary Valve Replacement?
Bibliographic record
Abstract
Introduction: Principal strain analysis (PSA) quantifies 3-dimensional deformation using speckle tracking echocardiography (3D-STE) to objectively define global and regional myocardial shortening amplitude and directionality, which is not affected by through-plane motion. It integrates circumferential (C), longitudinal (L), and C-L shear strains into a single deformation, expressed as PS lines (Fig. 1). Aim of this study was to apply PSA to characterize right ventricular (RV) function after Tetralogy of Fallot (TOF) repair. Hypothesis: PS provides novel description of RV function following TOF repair and may help determine subsequent need for pulmonary valve replacement (PVR). Methods: We prospectively enrolled 40 TOF patients (11.0±4.9 years) evaluated 10.0±4.5 years after corrective surgery, including 7 candidates awaiting PVR, and 40 age-matched controls (12.9±3.7 years). 3D-STE images were analyzed offline using Tomtec and Matlab-based post-processing software. Results: TOF patients had significantly larger RV volumes and decreased RVEF (EDVi: 106±18 versus 63±12 mL/m 2 , RVEF: 48±5 vs 57±4%, respectively, both p< 0.001). All global strain values were significantly decreased in TOF patients (GPS: -22.7±2.5 versus -25.8±2.0%, GCS: -10.6±3.4 versus -15.8±2.5%, GLS: -9.1± 6.3 versus -15.2±2.3%, GLS (2D): -20.3±4.5 versus -24.7±3.9 %, respectively, all p<0.001). Figure 2 shows PS magnitude and angle for control and TOF patient. Compared with controls, TOF patients demonstrated regionally lower PS strain (red areas) with preserved contractile angles. Among global strain amplitudes, PS showed best sensitivity (86%) and specificity (74%) for predicting subsequent need for PVR (Table1) (ROC: 0.76, cut off value: -22.9%). Conclusions: PS provides novel characterization of 3D RV deformation after TOF repair and is associated with subsequent need for PVR. Further research is warranted to determine its incremental value for guiding timing of PVR.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.003 | 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".