Prognostic value of time-related changes of cardiopulmonary exercise testing indices in stable chronic heart failure: a pragmatic and operative scheme

BackgroundAlthough peak oxygen consumption (VO2) is an objective measurement of functional capacity linked to survival, most clinicians use clinical history to monitor changes over time of functional disability. The aim was to verify the prognostic value of time-related changes (δ) of symptom-limited cardiopulmonary exercise testing (CPX) indices in stable chronic heart failure (CHF).Design and methodsWe studied 231 stable CHF patients (200 men) with left ventricular ejection fraction (LVEF) of 24 ±8% and peak VO2 of 14.3 ± 8 ml/kg per min, who performed two symptom-limited CPX over time.ResultsThe two incremental CPX were separated by a mean interval of 258 ± 42 days; 59 (26%) suffered cardiovascular death or underwent urgent heart transplantation during the follow-up (1167 ± 562 days). Peak VO2, LVEF (measured at second evaluation), δpeak VO2 and δNYHA (New York Heart Association classification) were selected as independent predictors in the total population, and LVEF, δpeak VO2, and NYHA in patients wi...