Paradoxical Low-Flow, Low-Gradient Severe Aortic Stenosis Despite Preserved Ejection Fraction Is Associated With Higher Afterload and Reduced Survival
Why is this work in the frame?
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Full frame distilled prediction
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.
- Candidate categories
- none
- Consensus categories
- none
- Domain
- Candidate signal: noneConsensus signal: none
- Study design
- Candidate signal: ObservationalConsensus signal: Observational
- Genre
- Candidate signal: EmpiricalConsensus signal: Empirical
- Teacher disagreement score
- 0.003
- Threshold uncertainty score
- 0.629
- Validation status
machine_predicted_unvalidated·codex-gemma-dda1882f352a
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| 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) | 0.000 | 0.000 |
Machine scores (provisional)
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
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.
- Teacher spread
- 0.275 · how far apart the two teachers sit on this one work
- Validation status
score_only:v0-immature-baseline· verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it
Abstract
BACKGROUND: Recent studies and current clinical observations suggest that some patients with severe aortic stenosis on the basis of aortic valve area may paradoxically have a relatively low gradient despite the presence of a preserved left ventricular (LV) ejection fraction. The objective of the present study was to document the prevalence, potential mechanisms, and clinical relevance of this phenomenon. METHODS AND RESULTS: We retrospectively studied the clinical and Doppler echocardiographic data of 512 consecutive patients with severe aortic stenosis (indexed aortic valve area < or = 0.6 cm2 x m(-2)) and preserved LV ejection fraction (> or = 50%). Of these patients, 331 (65%) had normal LV flow output defined as a stroke volume index > 35 mL x m2, and 181 (35%) had paradoxically low-flow output defined as stroke volume index < or = 35 mL x m(-2). When compared with normal flow patients, low-flow patients had a higher prevalence of female gender (P<0.05), a lower transvalvular gradient (32+/-17 versus 40+/-15 mm Hg; P<0.001), a lower LV diastolic volume index (52+/-12 versus 59+/-13 mL x m(-2); P<0.001), lower LV ejection fraction (62+/-8% versus 68+/-7%; P<0.001), a higher level of LV global afterload reflected by a higher valvulo-arterial impedance (5.3+/-1.3 versus 4.1+/-0.7 mm Hg x mL(-1) x m(-2); P<0.001) and a lower overall 3-year survival (76% versus 86%; P=0.006). Only age (hazard ratio, 1.04; 95% CI, 1.01 to 1.08; P=0.025), valvulo-arterial impedance > 5.5 mm Hg x mL(-1) x m(-2) (hazard ratio, 2.6; 95% CI, 1.2 to 5.7; P=0.017), and medical treatment (hazard ratio, 3.3; 95% CI, 1.8 to 6.7; P=0.0003) were independently associated with increased mortality. CONCLUSION: Patients with severe aortic stenosis may have low transvalvular flow and low gradients despite normal LV ejection fraction. A comprehensive evaluation shows that this pattern is in fact consistent with a more advanced stage of the disease and has a poorer prognosis. Such findings are clinically relevant because this condition may often be misdiagnosed, which leads to a neglect and/or an underestimation of symptoms and an inappropriate delay of aortic valve replacement surgery.
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.
The record
- Venue
- Circulation
- Topic
- Cardiac Valve Diseases and Treatments
- Field
- Medicine
- Canadian institutions
- Université Laval
- Funders
- Canadian Institutes of Health Research
- Keywords
- MedicineCardiologyAfterloadInternal medicineEjection fractionStroke volumeStenosisAortic valve stenosisHazard ratioHemodynamicsHeart failureConfidence interval
- Has abstract in OpenAlex
- yes