Development and Initial Results from the Canadian Cardiac Amyloidosis Pyrophosphate Imaging Registry (CAPER)
Bibliographic record
Abstract
BACKGROUND: Transthyretin cardiac amyloidosis (ATTR-CM) is an increasingly recognized cause of heart failure in older adults. Technetium-99m pyrophosphate (PYP) imaging has emerged as a highly effective tool for diagnosing ATTR-CM. We established a multicentre Canadian registry to provide a platform for research regarding the prevalence of ATTR-CM and accuracy of methods for screening or diagnosis. METHODS: Tc]PYP image files were transferred to the core laboratories. RESULTS: Tc]PYP scans increased from 18 in 2016 to 515 in 2022, with the proportion of patients with ATTR-CM ranging from 41% to 19% since 2017. The risk score proposed by Davies et al. had higher area under the receiver operating characteristic curves for ATTR-CM (0.792, 95% confidence interval [CI], 0.771-0.813) compared with the score proposed by Nitsche et al. (0.750; 95% CI, 0.727-0.774; P = 0.002). CONCLUSIONS: Tc]PYP imaging at 4 Canadian centres, with detailed clinical and imaging data. This registry, which continues to grow over time, will serve as an important source for evidence regarding diagnosis and management of ATTR-CM.
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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 | 0.006 | 0.018 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.007 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.003 | 0.001 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.001 | 0.001 |
| 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".