Determinants of changes in peak oxygen consumption in patients with new-onset heart failure

BACKGROUND: Peak oxygen consumption (pVO₂) is a key predictor of mortality and morbidity in patients with heart failure with reduced ejection fraction (HFrEF).

METHODS: From December 2022 to September 2023, patients with new-onset HFrEF were prospectively enrolled from a heart failure outpatient clinic. All patients underwent at least 12 weeks of guideline-directed medical therapy (GDMT) initiation and management, including physical training and education. Cardiopulmonary exercise testing (CPET), medication, echocardiography, and clinical data were collected at baseline and after 12 weeks. Associations with pVO₂ changes were examined using univariable and multivariable regression analyses.

RESULTS: We included 48 patients (median age 73 years, 20.8% women) with baseline left ventricular ejection fraction (LVEF) of 30% ± 7 and pVO₂ of 18.1 ± 5.6 mL/min/kg. After 12 weeks, pVO₂ increased by 2.2 mL/min/kg (95% CI: 1.3-3.1, p < 0.001) and LVEF improved to 44% (+14% [95% CI: 12-17, p < 0.001]). In the multivariable model, reductions in N-terminal pro-B-type natriuretic peptide (NT-proBNP) and body mass index (BMI) were associated with higher pVO₂ (β = -1.11 [95% CI: -2.15 to -0.06, p = 0.039]; β = -1.62 [95% CI: -2.99 to -0.25, p = 0.023]). Higher left atrial end-systolic volume index (LAESVi) was also associated with increased pVO₂ (β = 0.23 [95% CI: 0.10-0.35, p = 0.001]).

CONCLUSION: GDMT was associated with improvements in cardiorespiratory fitness and LVEF in patients with new-onset HFrEF. Reductions in NT-proBNP, decreases in BMI, and increases in LAESVi were independently associated with pVO₂ improvements after 12 weeks.