Peak oxygen uptake in older adults with heart failure: a systematic review and meta-analysis
Bibliographic record
Abstract
Reduced peak oxygen uptake (V̇O₂peak) is a hallmark of heart failure (HF) and aging, but studies on V̇O₂peak in older HF patients are limited. We compared V̇O₂peak in older HF patients versus controls and investigated differences across the age continuum: young-old (YO, 60-69 years), middle-old (MO, 70-79 years), and oldest-old (OO, ≥ 80 years). PubMed was searched (1967 May 2024) for studies meeting the following inclusion criteria: (1) HF patients with mean age ≥ 65 years; (2) V̇O₂peak measured via maximal cardiopulmonary exercise testing, and (3) control group for aim 1. For aim 2, studies had to compare V̇O₂peak within the age-subgroups. Random-effects meta-analysis was conducted, comparing V̇O₂peak (primary aim, and Fick determinants when reported) between HF and controls (aim 1), and V̇O₂peak between older age-subgroups (aim 2). Results are presented as weighted mean differences (WMD) with 95% confidence intervals. From 2788 screened articles, 38 studies were included. For aim 1, 30 studies (HF: n = 1093, mean age 70 years, 46% female; controls: n = 942, mean age 69 years, 52% female) demonstrated a significantly lower V̇O₂peak in HF (WMD - 8.8 mL/kg/min, [95% CI] - 10.3 to - 7.3 mL/kg/min). In the subset of patients where Fick determinants were measured, peak cardiac output and heart rate were lower in HF versus controls. For aim 2, eight studies showed progressively lower V̇O₂peak with age: MO vs. YO (- 1.5 mL/kg/min) and OO vs. MO (- 1.2 mL/kg/min). Older HF patients exhibit significant V̇O₂peak reductions compared to controls, with progressively lower V̇O₂peak values observed across the older age continuum.
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.
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 | 0.008 | 0.018 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.016 | 0.026 |
| Bibliometrics | 0.004 | 0.005 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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 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".