Tanscatheter aortic valve replacement for asymptomatic aortic stenosis - A revisited and contrarian meta-analysis
Bibliographic record
Abstract
Abstract Importance Using aggregated data, two recent meta-analyses have concluded that early aortic valve replacement (AVR) was associated with reduced adverse events compared to clinical surveillance in severe but asymptomatic aortic stenosis. However, individual patient data was not used and the possibility and extent of bias due to the unblinding trial design were not considered. Objective Using reconstructed individual patient level data, the possiblity of early bias was investigated and a meta-analysis of longer term benefits was performed using one year landmark data. Evidence Review Four randomized trials, as identified from previous systematic reviews, showed important clinical and statistical heterogeneity in year one AVR crossovers to cardiovascular hospitalizations. To minimize any early bias from unblinding, one year landmark analyses were performed separately for each trial and combined in a Bayesian (hierarchical) meta-analysis. Findings The largest trial with a TAVR intervention arm was the only trial to show improved outcomes in the first year, driven almost completely by an approximate two fold increase in the crossover rate compared to previous SAVR intervention trials. A one year landmark meta-analysis showed no long term benefit for AVR compared to CS for the primary outcome of mortality and cardiovascular hospitalizations for any individual study or for the pooled result (RR 0.70, 95% CI 0.34 - 1.08). Conclusions and Relevance The early benefit with TAVR in asymptomatic patients with severe aortic stenosis appears more driven by bias than by efficacy. Landmark analysis accounting for this potential bias show no longer term advantage for early AVR compared to clinical surveillance in this population. Key Points Question Does early intervention for severe asymptomatic aortic stenosis improve patient outcomes compared to clinical surveillance.? Findings A systematic review suggested early benefits were likely attributable not to interventional efficacy but rather bias due to an unblinded design for a subjective outcome. A one-year landmark meta-analysis showed no long term benefit for early intervention compared to clinical surveillance for the primary composite outcome of mortality and cardiovascular hospitalizations (RR 0.70, 95% CI 0.34 - 1.08). Meaning After accounting for possible early bias, landmark meta-analysis shows no longer term advantage for early intervention compared to clinical surveillance in this population.
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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 | 0.049 | 0.069 |
| Meta-epidemiology (narrow) | 0.003 | 0.001 |
| Meta-epidemiology (broad) | 0.014 | 0.051 |
| Bibliometrics | 0.005 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.005 | 0.002 |
| Open science | 0.002 | 0.002 |
| Research integrity | 0.003 | 0.004 |
| 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".