Salvioni E, Corrà U, Piepoli M, et al. - Given that one of the strongest cardiopulmonary exercise testing prognostic parameters in heart failure (HF) is ventilation vs carbon dioxide production (VE/VCO₂) and given the inadequacy of the current definition of normal VE/VCO₂ slope values, attributable to the fact that it was developed from small groups of individuals with especially limited number of women and elderly, researchers intended to define VE/VCO₂ slope prediction formulas in a sizable population. They also investigated if there would be a difference in the prognostic power of VE/VCO₂ slope in HF if expressed as a percentage of the predicted value or as an absolute value. In a total of 1,136 healthy individuals (68% male, age 44.9 ± 14.5, range 13–83 years), they computed the linear regressions between age and VE/VCO₂ slope. Thereafter, they employed age-adjusted and gender-adjusted formulas to foretell VE/VCO₂ slope to HF patients involved in the metabolic exercise test data linked with cardiac and kidney indexes score database. Experts concluded that the prognostic power of VE/VCO₂ in severe HF patients is strengthened by the percentage of predicted VE/VCO₂ slope value and they advise to prefer it over the absolute value for HF prognostication. An enhanced ability to recognize HF patients at high risk can be afforded by the widespread use of VE/VCO₂ slope expressed as percentage of predicted value.