Quantification of myocardial iron deposition by two-dimensional speckle tracking in patients with β-thalassaemia major and Blackfan–Diamond anaemia
Bibliographic record
Abstract
BACKGROUND: Cardiac disease related to transfusional iron overload is the leading cause of death in patients with β-thalassaemia major. Early myocardial iron deposition predates decreased left ventricular dysfunction and currently is best assessed by cardiac magnetic resonance. METHODS: Echocardiographic speckle tracking-derived myocardial mechanics were compared with cardiac MRI T2 star (T2*) calculations in 45 chronically transfused patients with β-thalassaemia major or Diamond-Blackfan anaemia (26 retrospectively and an additional 19 for validation). Two groups were studied: patients with presumed cardiac iron overload and interventricular T2* value ≤20 ms (low T2*) and patients with >20 ms (normal T2*). They were compared with a normal control group of 18 age- and gender-matched patients. RESULTS: Patients with low T2* had a uniform decrease in longitudinal and circumferential strain compared with normal controls (-16±3% vs -20±3% and -20±4% vs -23±5%, respectively; p<0.0005). Peak twist and peak apical rotation were lower in patients with low T2* than in those with normal T2* or normal control patients. Conversely, no significant difference was observed between patients with normal T2* and controls. There was a strong and direct logarithmic correlation between average global longitudinal strain and T2* values (r=-0.68, p=0.0007). Using a cut-off of ≤-17%, global longitudinal strain predicted a T2* value of <20 ms with a sensitivity of 76% and a specificity of 88%. CONCLUSION: Myocardial mechanics offers a simple alternative to cardiac MRI for assessing significant myocardial iron deposition.
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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 | 0.000 |
| 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".