Abstract 13116: Ventilatory Gas Exchange in Stable Coronary Artery Disease
Bibliographic record
Abstract
Introduction: Cardiopulmonary exercise testing (CPET) provides a non-invasive evaluation of exercise physiology via ventilatory gas exchange (VGE). We do not know how these assessments correlate with myocardial ischemia or angina symptoms in patients with stable single-vessel coronary artery disease (CAD). In this analysis, we use randomised, blinded data from the ORBITA trial to investigate the association between VGE, ischemia and symptoms in patients with severe single-vessel CAD. Methods: Patients underwent treadmill CPET using the smoothed-modified Bruce protocol, after a 6-week medical optimisation phase during which antianginals were uptitrated. Symptoms were assessed using the Seattle Angina Questionnaire (SAQ), EuroQOL 5 and Canadian Cardiovascular Society (CCS) angina class. Ischemia was quantified using fractional flow reserve (FFR), instantaneous wave-free ratio (iFR) and dobutamine stress echocardiography (DSE). Results: We assessed 195 patients [mean age 66.1±9.1, 143 (73.3%) male]. We found a significant association between peak oxygen uptake (VO 2 ) and minute ventilation to carbon dioxide (VE/VCO 2 ) slope, and physician assessed CCS class [P correlation(cor) <0.0001(Figure 1), P cor <0.0001, respectively], patient-reported SAQ angina frequency score [P cor <0.011(Figure 1), P cor <0.0001], physical limitation (P cor <0.0001, P cor =0.0001) and EuroQOL 5 visual analogue score (P cor = 0.0011, P cor =0.0019). There was no detectable relationship between peak VO 2 or VE/VCO 2 slope, and FFR, iFR or DSE (p>0.05, for all). Patients with an oxygen pulse plateau however, had higher dobutamine stress echo score compared to those without (+0.71; 95%CI 0.22-1.21, p=0.0049). Conclusions: The association between VGE and angina symptoms is stronger than its ability to detect severity of myocardial ischemia. This analysis highlights the complexity of the relationship between symptoms, functional capacity and myocardial ischemia.
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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 | 0.002 |
| 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 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".