New Parameters of Cardiopulmonary Exercise Testing in Patients with Chronic Heart Failure: Practical Applications

Cardiopulmonary exercise testing (CPX) has become the cornerstone of risk stratification for heart failure patients. Peak oxygen consumption (VO2) was the first CPX variable to demonstrate prognostic value and is still the most frequently analyzed variable in clinical practice. More recently, several investigations have shown that ventilatory efficiency, typically expressed as the minute ventilation/carbon dioxide production (VE/VCO2) slope, is a strong prognostic marker in patient with HF. The majority of studies report the VE/VCO2 slope to be prognostically superior to peak VO2 which underscore the clinical importance of assessing ventilatory efficiency in HF patients. Other expressions of ventilatory inefficiency like exercise oscillatory breathing (EOB), oxygen uptake efficiency slope (OUES), end-tidal carbon dioxide pressure (PET CO2) at rest, and haemodynamic responses such as heart rate recovery (HRR) are strong predictors of outcomes in patients with heart failure (HF). So there is a need for simplified approaches that integrate the additive prognostic information from cardiopulmonary exercise testing.