Can Ventilatory Efficiency Be Used to Classify Patients with Heart Failure?

Peak oxygen consumption (VO₂) during cardiopulmonary exercise testing is commonly used for risk stratification in heart failure. Previous studies have suggested that ventilatory efficiency, expressed as the minute ventilation/carbon dioxide production (VE/VCO₂) slope, is a superior determinant of HF prognosis. Investigators at five centers in the U.S. and Italy developed a system for classifying ranges of VE/VCO₂ slope and compared the accuracy of VE/VCO₂ slope with that of VO₂ in predicting cardiovascular events in patients with HF from 1993 to 2006.

In 448 consecutive patients (mean age, 56.9; 79% male; mean LV ejection fraction, 32.5%) who underwent symptom-limited cardiopulmonary exercise testing with a 2-year follow-up, VE/VCO₂ slope pr…