BACKGROUND: Oxygen consumption (VO2) has previously been used for prognosis and risk stratification in patients with heart failure. More recent research has introduced VE/VCO2 slope as a prognostic measure. Risk of mortality is thought to increase when VE/VCO2 slope values are greater than 34. Therefore, the purpose of this study was to cross-sectionally examine VE/VCO2 slope in systolic heart failure (SHF) and diastolic heart failure (DHF) as well as age-matched healthy controls. METHODS AND RESULTS: Maximal graded exercise tests were conducted on 147 patients (59 DHF, 60 SHF, and 28 controls) using a bicycle ergometer. Breath-by-breath expired gas analysis was performed using a commercially available system with on-line computer calculations. VE/VCO2 slope was calculated from a regression line of minute ventilation and carbon dioxide production. One-way analysis of covariance with a Bonferroni post hoc test and Pearson correlations were used for statistical analysis. VE/VCO2 slope was significantly higher in SHF when compared to both DHF (37 +/- 8 vs. 34 +/- 7, P = .03) and controls (37 +/- 8 vs. 32 +/- 5, P = .002). No significant difference was observed between DHF and healthy controls (34 +/- 7 vs. 32 +/- 5, P = .52). Additional analysis resulted in significant correlations between VO2 and VE/VCO2 slope in systolic heart failure patients (r = -0.40, P = .002); however, there was no significant relationships in diastolic heart failure patients (r = -0.09, P = .49) or in controls (r = 0.13, P = .50). CONCLUSIONS: VE/VCO2 slope is significantly higher in patients with SHF compared with DHF and healthy controls.
BACKGROUND:Oxygen consumption (VO2) has previously been used for prognosis and risk stratification in patients with heart failure. More recent research has introduced VE/VCO2 slope as a prognostic measure. Risk of mortality is thought to increase when VE/VCO2 slope values are greater than 34. Therefore, the purpose of this study was to cross-sectionally examine VE/VCO2 slope in systolic heart failure (SHF) and diastolic heart failure (DHF) as well as age-matched healthy controls. METHODS AND RESULTS: Maximal graded exercise tests were conducted on 147 patients (59 DHF, 60 SHF, and 28 controls) using a bicycle ergometer. Breath-by-breath expired gas analysis was performed using a commercially available system with on-line computer calculations. VE/VCO2 slope was calculated from a regression line of minute ventilation and carbon dioxide production. One-way analysis of covariance with a Bonferroni post hoc test and Pearson correlations were used for statistical analysis. VE/VCO2 slope was significantly higher in SHF when compared to both DHF (37 +/- 8 vs. 34 +/- 7, P = .03) and controls (37 +/- 8 vs. 32 +/- 5, P = .002). No significant difference was observed between DHF and healthy controls (34 +/- 7 vs. 32 +/- 5, P = .52). Additional analysis resulted in significant correlations between VO2 and VE/VCO2 slope in systolic heart failurepatients (r = -0.40, P = .002); however, there was no significant relationships in diastolic heart failurepatients (r = -0.09, P = .49) or in controls (r = 0.13, P = .50). CONCLUSIONS: VE/VCO2 slope is significantly higher in patients with SHF compared with DHF and healthy controls.
Authors: Katja Heinicke; Tanja Taivassalo; Phil Wyrick; Helen Wood; Tony G Babb; Ronald G Haller Journal: Am J Physiol Regul Integr Comp Physiol Date: 2011-08-03 Impact factor: 3.619
Authors: Dalane W Kitzman; W Gregory Hundley; Peter H Brubaker; Timothy M Morgan; J Brian Moore; Kathryn P Stewart; William C Little Journal: Circ Heart Fail Date: 2010-06-01 Impact factor: 8.790
Authors: Daniel E Forman; Robert Clare; Dalane W Kitzman; Stephen J Ellis; Jerome L Fleg; Toni Chiara; Gerald Fletcher; William E Kraus Journal: Am Heart J Date: 2009-10 Impact factor: 4.749