Meta-analysis: Cardiac Resynchronization Therapy for Patients With Less Symptomatic Heart Failure
Bibliographic record
Abstract
BACKGROUND: Cardiac resynchronization therapy (CRT) reduces morbidity and mortality in patients with advanced symptoms of heart failure. PURPOSE: To assess the benefits and harms of CRT in patients with advanced heart failure and those with less symptomatic disease. DATA SOURCES: A search of electronic databases (1950 to December 2010), hand-searching of reference lists, and unpublished data from principal investigators. Searches were not limited to the English language. STUDY SELECTION: Randomized, controlled trials of CRT compared with usual care and right or left ventricular pacing in adults with heart failure and a left ventricular ejection fraction of 0.40 or less. DATA EXTRACTION: Two reviewers performed independent study selection, data abstraction, and quality assessment by using the Cochrane tool for assessing risk for bias. DATA SYNTHESIS: There were 9082 patients in 25 trials. In patients with New York Heart Association (NYHA) class I and II symptoms, CRT reduced all-cause mortality (6 trials, 4572 participants; risk ratio [RR], 0.83 [95% CI, 0.72 to 0.96]) and heart failure hospitalizations (4 trials, 4349 participants; RR, 0.71 [CI, 0.57 to 0.87]) without improving functional outcomes or quality of life. In patients with NYHA class III or IV symptoms, CRT improved functional outcomes and reduced both all-cause mortality (19 trials, 4510 participants; RR, 0.78 [CI, 0.67 to 0.91]) and heart failure hospitalizations (11 trials, 2663 participants; RR, 0.65 [CI, 0.50 to 0.86]). The implant success rate was 94.4%; peri-implantation deaths occurred in 0.3% of trial participants, mechanical complications in 3.2%, lead problems in 6.2%, and infections in 1.4%. LIMITATION: Subgroup analyses were underpowered and lack data for persons with NYHA class I symptoms, atrial fibrillation, chronic kidney disease, or right bundle branch block. CONCLUSION: Cardiac resynchronization therapy is beneficial for patients with reduced left ventricular ejection fraction, symptoms of heart failure, and prolonged QRS, regardless of NYHA class. PRIMARY FUNDING SOURCE: None.
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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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.008 | 0.004 |
| Bibliometrics | 0.001 | 0.001 |
| 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".