Peak oxygen uptake in older adults with heart failure: a systematic review and meta-analysis

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.