Fibroblast activation following myocardial infarction and left ventricular remodelling
Bibliographic record
Abstract
Abstract Background Novel molecular positron emission tomography (PET) assessments of fibrosis are now available but have not been compared directly to cardiovascular magnetic resonance (CMR), the current reference standard for myocardial scar assessment. Using 68Gallium-fibroblast activation protein inhibitor (FAPI), a radiotracer that binds to activated fibroblasts, we compared CMR and PET assessments of myocardial scar following ST-elevation myocardial infarction. Methods Hybrid 68Ga-FAPI-46 PET/MR with gadolinium-based contrast agent was performed in 40 patients within 4 weeks of acute ST-elevation myocardial infarction (acute STEMI) with 19 returning at 12 weeks for repeat PET/MR (subacute STEMI). Scar burden (%LGE) was measured on late enhancement short axis CMR images (Circle Cardiovascular Imaging software, Canada). Volume and intensity of global myocardial 68Ga-FAPI uptake was quantified (QPET, Cedars Sinai, Los Angeles) to determine the volume myocardium with tracer uptake (%68Ga-FAPI) and intensity of PET signal (target-to-background ratio, TBRmax) after correcting for right atrial blood-pool activity. Results In acute STEMI, high intensity uptake of 68Ga-FAPI was observed localized to the infarct. The area of fibroblast activation greatly exceeded the area of scar detected by late gadolinium enhancement (LGE) (%68Ga-FAPI 26.6+-15.4% vs 14.5+-11.4%, p<0.001). 68Ga-FAPI volume and intensity declined between acute and subacute STEMI (%68Ga-FAPI 26.6+-15.4% vs 12.8+-8.1%, p<0.001, TBRmax 3.9+-1.1 vs 2.7+-0.7, p<0.001). By week 12, there was no difference between the area of fibroblast activation detected by 68Ga-FAPI uptake and area of scar detected by LGE (%68Ga-FAPI 12.8+-8.1% vs %LGE 10.3+-6.1%, ns). Conclusion Molecular PET assessments of myocardial scar formation provide different but complementary information to structural assessments of myocardial scar. Fibroblast activation following myocardial infarction is a dynamic process that can be non-invasively measured for the first time by 68Ga-FAPI PET.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.002 |
| 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 | 0.001 |
| 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".