Abstract 4345633: Left Atrial Lipomatous Metaplasia Quantified by Contrast-Enhanced Cardiac Computed Tomography in Patients with Atrial Fibrillation
Bibliographic record
Abstract
Introduction/Background: Left atrial (LA) pericardial and epicardial fat are associated with atrial fibrillation (AF). However, the association of LA intramyocardial fat, i.e. lipomatous metaplasia (LALM), with AF persistence and ablation outcomes is understudied. Research Question/Hypothesis: Do the total and regional distributions of LALM differ between paroxysmal and persistent AF, and does higher LALM burden predict early AF recurrence after catheter ablation? Methods/Approach: We retrospectively analyzed 100 patients who underwent contrast-enhanced cardiac computed tomography less than one year before AF ablation. The LA was segmented using ADAS software into standardized regions (Panel A) and LALM was quantified using intensity thresholds [−180 to 0 Hounsfield unit (HU)]. Total and regional LALM burdens were expressed as percentages of total LA myocardial and respective regional volumes. For transmural analysis, the myocardium was equally divided into 20%, 40%, 60%, and 80% wall depth-layers from sub-endocardium to sub-epicardium. Patients were stratified by AF persistence and by freedom from or recurrence of AF (≥30 s) beyond a three-month blanking period. Results/Data: Total LALM comprised a median of 16.6% (interquartile range: 11.0–21.1%) of the total LA myocardial volume. Regional burden was highest at the right (28.1%) and left (19.8%) pulmonary vein (PV) carinae, followed by the inferior wall (19.6%), interatrial septum (15.0%), posterior wall (14.1%), lateral wall (12.7%), and superior wall (10.7%). Patients with persistent AF (n = 43) had a significantly higher LALM percentage than those with paroxysmal AF (n = 57; 17.2% vs 16.1%, p = 0.03) (Panel B). No significant difference was found between patients with and without AF recurrence following ablation (16.4% vs 16.8%, p = 0.82) (Panel C). A transmural gradient was observed, with LALM increasing from the sub-endocardium (3.5%) to the sub-epicardium (24.9%, p < 0.001) (Panel D). Conclusions: LALM percentage is significantly greater in persistent than paroxysmal AF. Regionally, the highest percentages are found at the right and left PV carinae, followed by the inferior wall, and interatrial septum. Further investigation into LALM pathogenesis and its association with treatment outcomes is warranted.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".