Myocardial Ischemia and Mobilization of Circulating Progenitor Cells
Bibliographic record
Abstract
Background The response of progenitor cells (PCs) to transient myocardial ischemia in patients with coronary artery disease remains unknown. We aimed to investigate the PC response to exercise‐induced myocardial ischemia (ExMI) and compare it to flow mismatch during pharmacological stress testing. Methods and Results A total of 356 patients with stable coronary artery disease underwent 99mTc‐sestamibi myocardial perfusion imaging during exercise (69%) or pharmacological stress (31%). CD 34 + and CD 34 + /chemokine (C‐X‐C motif) receptor 4 PC s were enumerated by flow cytometry. Change in PC count was compared between patients with and without myocardial ischemia using linear regression models. Vascular endothelial growth factor and stromal‐derived factor‐1α were quantified. Mean age was 63±9 years; 76% were men. The incidence of Ex MI was 31% and 41% during exercise and pharmacological stress testing, respectively. Patients with Ex MI had a significant decrease in CD 34 + /chemokine (C‐X‐C motif) receptor 4 (−18%, P =0.01) after stress that was inversely correlated with the magnitude of ischemia ( r =−0.19, P =0.003). In contrast, patients without Ex MI had an increase in CD 34 + /chemokine (C‐X‐C motif) receptor 4 (14.7%, P =0.02), and those undergoing pharmacological stress had no change. Plasma vascular endothelial growth factor levels increased (15%, P <0.001) in all patients undergoing exercise stress testing regardless of ischemia. However, the change in stromal‐derived factor‐1α level correlated inversely with the change in PC counts in those with Ex MI ( P =0.03), suggesting a greater decrease in PC s in those with a greater change in stromal‐derived factor‐1α level with exercise. Conclusions Ex MI is associated with a significant decrease in circulating levels of CD 34 + /chemokine (C‐X‐C motif) receptor 4 PC s, likely attributable, at least in part, to stromal‐derived factor‐1α–mediated homing of PC s to the ischemic myocardium. The physiologic consequences of this uptake of PC s and their therapeutic implications need further investigation.
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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 | 0.000 | 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) | 0.001 | 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".