Cardiopulmonary exercise testing and prognosis in heart failure due to systolic left ventricular dysfunction: a validation study of the European Society of Cardiology Guidelines and Recommendations (2008) and further developments

Aims: The study aims were to validate the cardiopulmonary exercise testing (CPET) parameters recommended by the European Society of Cardiology 2008 Guidelines for risk assessment in heart failure (HF) (ESC-predictors) and to verify the predictive role of 11 supplementary CPET (S-predictors) parameters. Methods and results: We followed 749 HF patients for cardiovascular death and urgent heart transplantation for 3 years: 139 (19%) patients had cardiac events. ESC-predictors - peak oxygen consumption (VO2), slope of minute ventilation vs carbon dioxide production (VE/VCO2) and exertional oscillatory ventilation - were all related to outcome at univariate and multivariable analysis. The ESC/2008 prototype based on ESC-predictors presented a Harrell's C concordance index of 0.725, with a likely chi(2) of 98.31. S-predictors - predicted peak VO2, peak oxygen pulse, peak respiratory exchange ratio, peak circulatory power, peak VE/VCO2, VE/VCO2 slope normalized by peak VO2, VO2 efficiency slope, ventilatory anaerobic threshold detection, peak end-tidal CO2 partial pressure, peak heart rate, and peak systolic arterial blood pressure (SBP) - were all linked to outcome at univariate analysis. When individually added to the ESC/2008 prototype, only peak SBP and peak O-2 pulse significantly improved the model discrimination ability: the ESC+peak SBP prototype had a Harrell's C index 0.750 and reached the highest likely chi(2) (127.16, p<0.0001). Conclusions: We evaluated the longest list of CPET prognostic parameters yet studied in HF: ESC-predictors were independent predictors of cardiovascular events, and the ESC prototype showed a convincing predictive capacity, whereas none of 11 S-predictors enhanced the prognostic performance, except peak SBP.