VO2 peak as a predictor of COPD severity

<bold>Background:</bold> Peak oxygen uptake (VO2-peak) assessed during cardiopulmonary exercise testing (CPET) has a promising prognostic value in chronic obstructive pulmonary disease (COPD). However, there isn’t a VO2-peak reference range. <bold>Objectives:</bold> Assess VO2-peak optimal value for all-cause mortality prediction in COPD patients. <bold>Methods:</bold> Retrospective single-center cohort study conducted at a pneumology outpatient clinic, examining patients with COPD enrolled between 2012 and 2018 (follow-up extended until 2024). The exposure was VO2-peak and the main outcome was 10-year all-cause mortality. Demographic, clinical and CPET data were studied. Survival analysis was assessed through Kaplan-Meier methods/ Tarone-Ware tests, and compared across patients with initial VO2-peak above or below the discriminant threshold identified by Receiver Operating Characteristics curve. <bold>Results:</bold> Among the 99 patients (81% male) included, with a median follow-up of 6.0 years [3.3–7.8], the overall 10-year survival rate was 53.5%. In univariate analyses, older age (69 vs 63 years old, p=0.005), lower VO2-peak (13.8 vs 15.2 mL/kg/min, p=0.006) and lung cancer (30.4% vs 5.7%,p<0.001) were associated with higher mortality. Optimal VO2-peak threshold for discrimination of 10-year survival was 14.15 mL/kg/min (VO2-peak≤14.15 mL/kg/min: 20.1% vs VO2-peak >14.15 mL/kg/min: 60.7%, p=0.022). After adjustment for confounding factors, VO2-peak ≤14.15 mL/kg/min remained a significant predictor of higher mortality (HR 2.3, CI 95% [1.1–4.8]). <bold>Conclusions:</bold> In our cohort VO2-peak ≤14.15 mL/kg/min was associated with higher mortality, consistent with other studies. Future inclusion of VO2-peak in COPD severity categorisation might be adequate.