Prognostic significance of cardiopulmonary exercise testing parameters for predicting all-cause mortality in chronic heart failure patients: a cohort study
P Iliakis, C Chrysohoou, M Dulay, C Fragoulis, P Xydis, A Baron, M Kariori, G Leontsinis, E Angouridaki, D Vlaikou, S Karamesinis Spinthakis, O Dar, K TsioufisAbstract
Background
Heart failure (HF) remains a significant challenge in global healthcare, contributing to frequent hospitalizations and elevated mortality rates. Cardiopulmonary exercise testing (CPET) provides a non-invasive mean of assessing how the cardiovascular, respiratory, and musculoskeletal systems function together.
Purpose
To evaluate whether CPET-derived measures could predict total mortality in HF patients, irrespective of their left ventricular ejection fraction.
Methods
A prospective cohort study involving 354 consecutive HF patients who underwent CPET between 2016 and 2022, was conducted. Clinical, biochemical, and CPET data were collected, with total mortality as the primary outcome. Using Cox proportional hazards models, independent risk factors associated with mortality were evaluated.
Results
Over an average follow-up period of 4.3 years, 45 patients (18.2%) died. Unadjusted analysis revealed that lower peak oxygen consumption (peak VO2), decreased oxygen uptake efficiency slope (OUES), and a steeper VE/VCO2 slope were all linked to higher CV mortality. However, after adjusting for multiple variables, only OUES remained a strong independent predictor of death (HR 0.997; 95%CI [0.996, 0.998]; p=0.001). Further analysis revealed that OUES below threshold of 1900 was associated with significantly worse survival rates.
Conclusion
The efficiency of the pulmonary, cardiovascular, and muscular systems in delivering and utilizing oxygen - as assessed through CPET-, seems to be an independent indicator of total mortality in HF patients, highlighting the importance of submaximal exercise markers in assessing long-term risk and optimizing the management of heart failure.graphical abstractK-M survival plots of certain CPET parameters