Improvement of LV functional performance in the chronic total coronary occlusion during the late stage is associated with the extensive collateral development
Bibliographic record
Abstract
In nine pigs a CTO was created by percutaneously inserting a fibrin plug (AngiosealΤΜ) into the mid-to-distal left anterior descending artery (LAD). Animals were studied six (n=3) or twelve weeks (n=6) later prior to sacrifice. An x-ray angiogram confirmed the LAD CTO at those time points. Cardiac MR (CMR) studies were then conducted on a 1.5T (n=6) or on a 3.0T MRI system (n=3), which included SSFP short axis sections for wall motion and post-gadolinium LGE-MRIs for viability. After sacrifice, both right and left coronary systems were injected with Microfil. X-ray or MSCT angiography of the fixed heart was obtained. A longitudinal cardiac section including the CTO lesion, proximal/distal LAD and the borders of infarction was removed and prepared in gel, then imaged in a micro-CT system at 27 micron resolution. LV functional parameters including wall thickness at end-systole (WTES) and end-diastole (WTED) were measured in border zone, infarct and remote region. Systolic wall thickening (SWT) was calculated using as (WTES-WTED) x100/WTED. CMR and micro-CT data were processed using commercial software. The extent of collaterals on micro-CT images was rated qualitatively using a score from 0 to 3, indicating that no, minimal, moderate, or extensive collaterals were observed. A Student’s t-test was used for the statistical significance of differences between measurements at 6 and 12 weeks. LGE-MRI determined the presence of LV myocardial infarction (MI). Tables 1 and 2 summarize the results of global and regional LV function measurements at both time points. Ejection fraction (LVEF) at 12 weeks was significantly greater than at 6 weeks (39.45±5.38% vs. 26.27±5.77%, P=0.01) although the extent of infarct was similar between these two groups (P=0.16). In border zone the WTES (11.31±1.72 vs. 8.67±0.57mm, P=0.04) and SWT (68.31±11.55% vs. 35.87±19.14%, P=0.01) increased at 12 versus 6 weeks. On the visual scores of collateral development, between 6 and 12 weeks, there was an increase in collateral number (1.33±0.58 vs. 2.83±0.41, p<0.003). Figure 1 similarly illustrates increased collateral development at the later time point. Compared to the minimal collateral formation in the 6 weeks’ CTO animal (A-E), extensive collateral development was observed in the 12 weeks’ CTO animal (F-J), which is consistent with the increased systolic wall thickening and better LV function performance measured from cine SSFP images in the late stage of CTO. A, F: end-systolic SSFP images; B, G: end-diastolic SSFP images; C, H: LGE-MRI images; D, I: rotational x-ray angiogram; E, J: 3D micro-CT images reconstructed from highlighted box regions of D and I. Black, green and orange arrows indicating infarct, border and remote region. Extensive collateral development during the late stage of myocardial repair after CTO may contribute to LV functional improvement through increased SWT in the border zone. This provides a potential explanation for preserved LV function witnessed in some patients with CTO.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".