Abstract P188: “False Positive” Stress Testing: Does Endothelial Vascular Dysfunction Explain ST-Segment Depression in the Absence of Clinical Coronary Artery Disease in Women?
Bibliographic record
Abstract
Background: Current guidelines do not endorse exercise electrocardiography (Ex-ECG) screening in asymptomatic adults due to poor diagnostic accuracy for clinical coronary artery disease (CAD), however Ex-ECG combined with other variables paradoxically has strong prognostic accuracy for cardiovascular mortality. Ex-ECG ST segment depression “false positive” results are common in women, who have higher rates of vascular dysfunction such as Raynaud’s and migraines compared to men. We hypothesized that ST segment depression indicates endothelial vascular dysfunction, which is known to predict an adverse prognosis. To test this hypothesis, we evaluated the relationship between Ex-ECG and peripheral endothelial vascular function in asymptomatic women. Methods: Asymptomatic women with no cardiac risk factors and normal resting ECG underwent maximal Bruce protocol Ex-ECG testing (GE Healthcare). Computer-generated Ex-ECG ST segment values were independently verified by 2 cardiologists. Based on established methods, endothelial vascular function was assessed by calculating reactive hyperemia index (RHI) using peripheral vascular testing (Endopat, Itamar). As established previously, RHI <1.68 is abnormal and indicates endothelial vascular dysfunction. Results: Among 35 women, mean age 54±8 years and BMI 24±4, there were 5 (14%) women with abnormal RHI. Women with abnormal RHI had a greater (more abnormal) ST/HR slope, a trend toward greater peak ST depression, and achieved lower METs than women with normal RHI (Table 1). Conclusion: Among asymptomatic women, endothelial vascular dysfunction was associated with abnormal Ex-ECG results characterized by greater ST/HR slope, greater ST depression, and lower exercise capacity. These findings suggest that “false positive” ST-segment depression in the absence of clinical CAD in women may be explained by endothelial vascular dysfunction. Our study further suggests that endothelial vascular dysfunction may explain the Ex-ECG diagnostic/prognostic paradox.
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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 | 0.001 | 0.004 |
| 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 | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.004 | 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".