Outcome and Impact of Surgery in Paradoxical Low-Flow, Low-Gradient Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction
Bibliographic record
Abstract
BACKGROUND: The clinical relevance and management of paradoxical low-flow, low-gradient aortic stenosis (LFLG-AS) with preserved left ventricular ejection fraction remain debated. The aim of this study is to determine the features and outcome of LFLG-AS assessed using cardiac catheterization. METHODS AND RESULTS: Between 2000 and 2010, 768 patients with preserved left ventricular ejection fraction (>50%) and severe AS (valve area ≤ 1 cm(2)) without other valvular disease underwent cardiac catheterization. Mean age was 74 ± 8 years, 42% were women, and 46% had associated coronary artery disease. The prevalence of LFLG (indexed left ventricular stroke volume <35 mL/m(2) and mean gradient <40 mm Hg), normal flow high gradient, normal flow low gradient, and low flow high gradient were 13%, 50%, 22%, and 15%, respectively. Compared with patients with normal flow high gradient, those with LFLG were significantly older, with significantly reduced systemic arterial compliance and vascular resistances and increased valvulo-arterial impedance (all P<0.05). Ten-year survival was reduced in LFLG-AS (32 ± 9%) compared with normal flow high gradient (66 ± 4%; P=0.0002). After adjustment for other risk factors, LFLG-AS was independently associated with reduced long-term survival (hazard ratio, 1.85; 95% confidence interval, 1.08-3.07; P=0.02). However, despite higher operative mortality, patients with LFLG-AS undergoing aortic valve replacement seemed to have better long-term survival than those managed conservatively (5-year survival rate: 63 ± 6% versus 38 ± 15%; P=0.007; hazard ratio, 0.23; 95% confidence interval, 0.09-0.59; P=0.002). CONCLUSIONS: This large cardiac catheterization-based study reports that the LFLG-AS entity is not rare and is associated with worse outcome whether treated medically or surgically. However, these patients may have better long-term survival if treated surgically. Further prospective studies are needed to confirm this finding.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. 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.
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)
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 teacher head, 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".