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Record W2904950765 · doi:10.1001/jamacardio.2018.4320

Outcomes From Transcatheter Aortic Valve Replacement in Patients With Low-Flow, Low-Gradient Aortic Stenosis and Left Ventricular Ejection Fraction Less Than 30%

2018· article· en· W2904950765 on OpenAlex

Why this work is in the frame

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

affAt least one author lists a Canadian institution in the pinned OpenAlex snapshot.
fundA Canadian funder is recorded on the work.

Bibliographic record

VenueJAMA Cardiology · 2018
Typearticle
Languageen
FieldMedicine
TopicCardiac Valve Diseases and Treatments
Canadian institutionsUniversity of TorontoSt. Michael's HospitalUniversité Laval
FundersCanadian Institutes of Health Research
KeywordsMedicineEjection fractionCardiologyInternal medicineStenosisAortic valve replacementAortic valve stenosisValve replacementStroke volumeAortic valveHeart failure

Abstract

fetched live from OpenAlex

Importance: In low-flow, low-gradient aortic stenosis (LFLG AS), the severity of left ventricular dysfunction remains a key factor in the evaluation of aortic valve replacement. Objective: To evaluate the clinical outcomes and changes in left ventricular ejection fraction (LVEF) after transcatheter aortic valve replacement (TAVR) in patients with LFLG AS and severe left ventricular dysfunction. Design, Setting, and Participants: This multicenter registry is a substudy of the True or Pseudo-Severe Aortic Stenosis-TAVI registry that included patients with classic LFLG AS, defined as a mean transvalvular gradient less than 35 mm Hg, an effective orifice area less than 1.0 cm2, and an LVEF of 40% or less. Patients were divided in groups with very low (<30%) LVEF and low (30%-40%) LVEF. Dobutamine stress echocardiography (DSE) was performed before TAVR in a subset with very low LVEF, and presence of contractile reserve was defined as an increase of 20% or more in stroke volume. Clinical outcomes were assessed at 1 and 12 months and yearly thereafter, and echocardiography was performed at 1-year follow-up. Retrospective data were collected from 2007 to 2013 and prospective data from January 2013 to March 2018. Data were analyzed from March to October 2018. Exposures: Transcatheter aortic valve replacement in patients with LFLG AS. Main Outcomes and Measures: Changes in LVEF over time; periprocedural and late mortality. Results: A total of 293 patients were included, including 128 (43.7%) with very low LVEF and 165 with low LVEF (56.3%). Their mean (SD) age was 80 (7) years, and most (214 [73.0%]) were men. The mean (SD) LVEF in the very low LVEF group was 22% (5%), compared with 37% (7%) in the low LVEF group (P < .001). There were no differences between groups in rates of periprocedural mortality and late mortality (median [interquartile range], 23 [6-38] months). Patients with very low LVEF displayed a greater increase in LVEF at the 1-year follow-up examination (mean absolute increase, 11.9% [95% CI, 8.8%-15.1%]), than the low LVEF group (3.6% [95% CI, 1.1%-6.1%]; P < .001). In 92 patients with very low LVEF who had preprocedural DSE, results showed a lack of contractile reserve in 45 (49%), but this had no effect on clinical outcomes or changes in LVEF over time. Conclusions and Relevance: In patients with LFLG AS and severe left ventricular dysfunction, TAVR was associated with similar clinical outcomes as in counterparts with milder left ventricular dysfunction. The TAVR procedure was associated with a significant increase in LVEF, irrespective of contractile reserve. These results support TAVR for LFLG AS, irrespective of the severity of left ventricular dysfunction and DSE results.

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.

Full frame distilled prediction

Teacher imitation

Not 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.

metaresearch head score (Codex)0.000
metaresearch head score (Gemma)0.000
Version: codex-gemma-dda1882f352aValidation status: machine_predicted_unvalidated
Candidate categoriesnone
Consensus categoriesnone
DomainCandidate signal: none · Consensus signal: none
Study designCandidate signal: Observational · Consensus signal: Observational
GenreCandidate signal: Empirical · Consensus signal: Empirical
Teacher disagreement score0.006
Threshold uncertainty score0.773

Codex and Gemma teacher scores by category

CategoryCodexGemma
Metaresearch0.0000.000
Meta-epidemiology (narrow)0.0000.000
Meta-epidemiology (broad)0.0010.001
Bibliometrics0.0000.000
Science and technology studies0.0000.000
Scholarly communication0.0000.000
Open science0.0000.000
Research integrity0.0000.000
Insufficient payload (model declined to judge)0.0000.000

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.

Opus teacher head0.008
GPT teacher head0.261
Teacher spread0.253 · how far apart the two teachers sit on this one work
Validation statusscore_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it