Influence of Heart Failure Etiology on the Prognostic Value of Peak Oxygen Consumption and Minute Ventilation/Carbon Dioxide Production Slope* (original) (raw)
Related papers
2006
Background: Cardiopulmonary exercise testing (CPX) clearly holds prognostic value in the heart failure (HF) population. Studies investigating the prognostic value of CPX in individuals with HF have consistently examined predominantly male groups. The purpose of the present study was to examine the prognostic value of CPX in a female HF group. Methods: Seventy-five female and 337 male subjects diagnosed with HF participated in this study. The ability of peak oxygen consumption (VO 2 ) and the minute ventilation/carbon dioxide production (VE/VCO 2 ) slope to predict cardiac-related events were assessed. Results: In the year following CPX, the female group suffered 26 cardiac-related events (8 deaths/18 hospitalizations), while the male group suffered 89 cardiac-related events (20 deaths/69 hospitalizations). The hazard ratios for peak VO 2 and the VE/VCO 2 slope were 4.0 (95% confidence interval: 2.6 -6.1, p < 0.001) and 4.2 (95% confidence interval: 2.7 -6.6, p < 0.001) in the male group and 3.8 (95% confidence interval: 1.7 -8.5, p < 0.001) and 4.3 (95% confidence interval: 1.8 -9.8, p < 0.001) in the female group. In both the male and female groups, Cox multivariate analysis revealed VE/VCO 2 slope was the strongest predictor of cardiac-related events while peak VO 2 added significant predictive value and was retained in the regression.
The lowest VE/VCO2 ratio during exercise as a predictor of outcomes in patients with heart failure
Journal of cardiac …, 2009
Background: The lowest minute ventilation (VE) and carbon dioxide production (VCO 2 ) ratio during exercise has been suggested to be the most stable and reproducible marker of ventilatory efficiency in patients with heart failure (HF). However, the prognostic power of this index is unknown. Methods and Results: A total of 847 HF patients underwent cardiopulmonary exercise testing (CPX) and were followed for 3 years. The associations between the lowest VE/VCO 2 ratio, maximal oxygen uptake (peak VO 2 ), the VE/VCO 2 slope, and major events (death or transplantation) were evaluated using proportional hazards analysis; adequacy of the predictive models was assessed using Akaike information criterion (AIC) weights. There were 147 major adverse events. In multivariate analysis, the lowest VE/ VCO 2 ratio (higher ratio associated with greater risk) was similar to the VE/VCO 2 slope in predicting risk (hazard ratios [HR] per unit increment 2.0, 95% CI 1.1e3.4, and 2.2, 95% CI 1.3e3.7, respectively; P ! .01), followed by peak VO 2 (HR 1.6, 95% CI 1.1e2.4, P 5 .01). Patients exhibiting abnormalities for all 3 responses had an 11.6-fold higher risk. The AIC weight for the 3 variables combined (0.94) was higher than any single response or any combination of 2. The model including all 3 responses remained the most powerful after adjustment for b-blocker use, type of HF, and after applying different cut points for high risk. Conclusions: The lowest VE/VCO 2 ratio adds to the prognostic power of conventional CPX responses in HF. (J Cardiac Fail 2009;15:756e762)
The Open Cardiovascular Medicine Journal, 2010
Background: Cardiopulmonary exercise testing with ventilatory expired gas analysis (CPET) has proven to be a valuable tool for assessing patients with chronic heart failure (CHF). The maximal oxygen uptake (peak V02) is used in risk stratification of patients with CHF. The minute ventilation-carbon dioxide production relationship (VE/VCO2 slope) has recently demonstrated prognostic significance in patients with CHF. Methods: Between January 2006 and December 2007 we performed CPET in 184 pts (146 M, 38 F, mean age 59.8 + 12.9 years), with stable CHF (96 coronary artery disease, 88 dilated cardiomyopathy), in NYHA functional class II (n.107)-III (n.77), with left ventricular ejection fraction (LVEF) < 45%,. The ability of peak VO2 and VE/VCO2 slope to predict cardiac related mortality and cardiac related hospitalization within 12 months after evaluation was examined. Results: Peak VO2 and VE/VCO2 slope were demonstrated with univariate Cox regression analysis both to be significant predictor of cardiac-related mortality and hospitalization (p < 0.0001, respectively). Non survivors had a lower peak VO2 (10.49 + 1.70 ml/kg/min vs. 14.41 + 3.02 ml/kg/min, p < 0.0001), and steeper Ve/VCO2 slope (41.80 + 8.07 vs. 29.84 + 6.47, p < 0.0001) than survivors. Multivariate survival analysis revealed that VE/VCO2 slope added additional value to VO2 peak as an independent prognostic factor (2: 56.48, relative risk: 1.08, 95% CI: 1.03-1.13, p = 0.001). The results from Kaplan-Meier analysis revealed a 1-year cardiac-related mortality of 75% in patients with VE/VCO2 slope > 35.6 and 25% in those with VE/VCO2 slope < 35.6 (log rank 2: 67.03, p < 0.0001) and 66% in patients with peak VO2 < 12.2 ml/kg/min and 34% in those with peak VO2 > 12.2 ml/kg/min (log rank 2: 50.98, p < 0.0001). One-year cardiac-related hospitalization was 77% in patients with VE/VCO2 slope > 32.5 and 23% in those with VE/VCO2 slope < 32.5 (log rank 2: 133.80, p < 0.0001) and 63% in patients with peak VO2 < 12.3 ml/kg/min and 37% in those with peak VO2 > 12.3 ml/kg/min (log rank 2: 72.86, p < 0.0001). The VE/VCO2 slope was demonstrated with receiver operating characteristic curve analysis to be equivalent to peak VO2 in predicting cardiac-related mortality (0.89 vs. 0.89). Although area under the receiver operating characteristic curve for the VE/VCO2 slope was greater than peak VO2 in predicting cardiacrelated hospitalization (0.88 vs 0.82), the difference was no statistically significant (p = 0.13). Conclusion: These results add to the present body of knowledge supporting the use of CPET in CHF patients. The VE/VCO2 slope, as an index of ventilatory response to exercise, is an excellent prognostic parameter and improves the risk stratification of CHF patients. It is easier to obtain than parameters of maximal exercise capacity and is of equivalent prognostic importance than peak VO2.
Prognostic value of end-tidal carbon dioxide during exercise testing in heart failure
2007
Background: The partial pressure of end-tidal carbon dioxide production (P ET CO 2 ) at ventilatory threshold (VT) has been shown to be strongly correlated with cardiac output during exercise in patients with heart failure (HF), but few data are available regarding its prognostic utility. Aims: The purpose of this study was to assess the ability of P ET CO 2 to predict cardiac-related events in a group of subjects with HF. Methods: One hundred and thirty subjects diagnosed with compensated HF underwent cardiopulmonary exercise testing (CPX). Peak oxygen consumption (VO 2 ), the minute ventilation-carbon dioxide production (VE/VCO 2 ) slope and P ET CO 2 were determined. Results: Receiver operating characteristic (ROC) curve analysis revealed that P ET CO 2 at the ventilatory threshold (VT) was a significant predictor of cardiac-related events (ROC area = 0.82, p < 0.001). The optimal P ET CO 2 at a VT threshold value for separating high (≤) and low (>) risk groups was 36.1 mm Hg (77% sensitivity, 69% specificity). In a multivariate Cox regression analysis, P ET CO 2 at VT added significant predictive value to the VE/VCO 2 slope and peak VO 2 . Conclusion: These results indicate that P ET CO 2 during CPX is a significant predictor of cardiac-related events in patients with HF. Clinical assessment of this variable in patients with HF undergoing CPX may therefore be warranted.
A cardiopulmonary exercise testing score for predicting outcomes in patients with heart failure
American Heart Journal, 2008
Objective The aim of this study is to evaluate the predictive accuracy of a cardiopulmonary exercise test (CPX) score. Background Cardiopulmonary exercise test responses, including peak VO 2 , markers of ventilatory inefficiency (eg, the VE/VCO 2 slope and oxygen uptake efficiency slope [OUES]), and hemodynamic responses, such as heart rate recovery (HRR) and chronotropic incompetence (CRI) are strong predictors of outcomes in patients with heart failure (HF). However, there is a need for simplified approaches that integrate the additive prognostic information from CPX.
Ischemic etiology of heart failure identifies patients with more severely impaired exercise capacity
2005
Background: Peak oxygen uptake (peak VO2) and the regression slope of ventilation against CO2 production during exercise (VE/VCO2 slope) are powerful prognostic indicators in patients with chronic heart failure (CHF). Our purpose was to evaluate the influence of CHF etiology on peak VO2 and VE/VCO2 slope, independently of demographic, clinical, Doppler-echocardiographic and neurohormonal factors. Methods: Data were collected from 239 CHF patients referred for a cardiopulmonary exercise test as part of their clinical evaluation. Patients were stratified according to their CHF etiology (ischemic versus non-ischemic). Results: The etiology of heart failure was ischemic in 143 patients (60%) and non-ischemic in 96 (40%). Patients with ischemic etiology, compared with those with non-ischemic etiology, showed a lower peak VO2 (15.4F4.2 versus 17.8F4.8 ml/kg/min, pb0.0001) and a steeper VE/VCO2 slope (38.1F6.8 versus 34F5.3, pb0.0001). In the univariate model, age (r=À0.36, pb0.0001), female sex (r=À0.21, p=0.001), ischemic CHF etiology (r=À0.26, pb0.0001) and NYHA class (r=À0.52, pb0.0001) correlated with peak VO2. At multivariate analysis, ischemic CHF etiology (b=À0.23, p=0.001) was a predictor of peak VO2 (R 2 =0.49) independently of age (b=À0.23, p=0.001), female sex (b=À0.25, p=0.0006) and NYHA class (b=À0.31, pb0.0001). Similarly, ischemic etiology (b=0.29, p=0.001) predicted the VE/VCO2 slope (R 2 =0.38) independently of E/A ratio (b=0.27, p=0.01) and resting heart rate (b=0.22, p=0.01). Conclusions: Etiology of heart failure may influence the functional capacity and the ventilatory response to exercise. D