Heart failure prognosis over time: how the prognostic role of oxygen consumption and ventilatory efficiency during exercise has changed in the last 20 years (original) (raw)
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Revista portuguesa de cardiologia : orgão oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, 2010
Cardiopulmonary exercise testing (CPET) is an objective method for assessment of functional capacity and for prognostic stratification of patients with chronic heart failure (CHF). In this study, we analyzed the prognostic value of a recently described CPET-derived parameter, the minute ventilation to carbon dioxide production slope normalized for peak oxygen consumption (VE/VCO2 slope/pVO2). We prospectively studied 157 patients with stable CHF and dilated cardiomyopathy who performed maximal CPET using the modified Bruce protocol. The prognostic value of VE/VCO2 slope/pVO2 was determined and compared with traditional CPET parameters. During follow-up 37 patients died and 12 were transplanted. Mean follow-up in surviving patients was 29.7 months (12-36). Cox multivariate analysis revealed that VE/VCO2 slope/pVO2 had the greatest prognostic power of all the parameters studied. A VE/VCO2 slope/pVO2 of > or = 2.2 signaled cases at higher risk. Normalization of the ventilatory respo...
Revista portuguesa de cardiologia : orgão oficial da Sociedade Portuguesa de Cardiologia = Portuguese journal of cardiology : an official journal of the Portuguese Society of Cardiology, 2011
A growing body of evidence shows the prognostic value of oxygen uptake efficiency slope (OUES), a cardiopulmonary exercise test (CPET) parameter derived from the logarithmic relationship between O(2) consumption (VO(2)) and minute ventilation (VE) in patients with chronic heart failure (CHF). To evaluate the prognostic value of a new CPET parameter - peak oxygen uptake efficiency (POUE) - and to compare it with OUES in patients with CHF. We prospectively studied 206 consecutive patients with stable CHF due to dilated cardiomyopathy - 153 male, aged 53.3±13.0 years, 35.4% of ischemic etiology, left ventricular ejection fraction 27.7±8.0%, 81.1% in sinus rhythm, 97.1% receiving ACE-Is or ARBs, 78.2% beta-blockers and 60.2% spironolactone - who performed a first maximal symptom-limited treadmill CPET, using the modified Bruce protocol. In 33% of patients an cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device (CRT-D) was implanted during follow-up. Peak VO(2), p...
CHEST Journal, 2005
Background: Peak oxygen consumption (V O 2) and minute ventilation (V E)/carbon dioxide production (V CO 2) slope have been widely demonstrated to have strong prognostic value in patients with heart failure (HF). In the present study, we investigated the effect of HF etiology on the prognostic applications of peak V O 2 and V E/V CO 2 slope. Methods: Two hundred sixty-eight subjects underwent symptom-limited cardiopulmonary exercise testing (CPX). The population was divided into ischemic (115 men and 22 women) and nonischemic (108 men and 23 women) subgroups. The occurrence of cardiac-related events over the year following CPX was compared between groups using receiver operating characteristic curve (ROC) analysis Results: Mean age ؎ SD was significantly higher (61.0 ؎ 10.0 years vs 50.3 ؎ 16.2 years) while mean peak V O 2 was significantly lower (15.0 ؎ 5.2 mL/kg/min vs 17.5 ؎ 6.7 mL/kg/min) in the ischemic HF group (p < 0.05). ROC curve analysis demonstrated that both peak V O 2 and V E/V CO 2 slope were significant predictors of cardiac events in both the ischemic group (peak V O 2 , 0.74; V E/V CO 2 slope, 0.76; p < 0.001) and the nonischemic group (peak V O 2 , 0.75; V E/V CO 2 slope, 0.86; p < 0.001). Optimal prognostic threshold values for peak V O 2 were 14.1 mL/kg/min and 14.6 mL/kg/min in the ischemic and nonischemic groups, respectively. Optimal prognostic threshold values for the V E/V CO 2 slope were 34.2 and 34.5 in the ischemic and nonischemic groups, respectively. Conclusions: Baseline and exercise characteristics were different between ischemic and nonischemic patients with HF. However, the prognostic power of the major CPX variables was strikingly similar. Different prognostic classification schemes based on HF etiology may therefore not be necessary when analyzing CPX responses in clinical practice.
European Heart Journal, 2005
Aims Predicting survival from peak exercise oxygen uptake (peak VO 2) in chronic heart failure (CHF) is hindered by its reduction if exercise duration is submaximal. The oxygen uptake efficiency slope (OUES) is a non-linear description of the ventilatory response to exercise, which has the potential to describe abnormalities even early in exercise. We evaluated the physiology of OUES and assessed its potential for prognostic information in patients with CHF. Methods and results Two hundred and forty-three patients with CHF (mean age 59 + 12 years) underwent cardiopulmonary exercise testing between May 1992 and July 1996. Mean peak VO 2 was 16.2 + 6.7 mL/kg/min, VE/VCO 2 slope 38 + 12.5, ventilatory anaerobic threshold 10.9 + 3.5 mL/kg/min, and OUES 1.6 + 0.7 L/min. The value for each variable fell across the New York Heart Association classes (P , 0.0001 by analysis of variance for each). When only the first 50% of each exercise test was used to calculate the variables, the value obtained for OUES changed the least (peak VO 2 25% difference and OUES 1% difference). After a median of 9 years of follow-up, 139 patients (57%) had died. Each of the exercise variables was a significant univariate predictor of prognosis but in a multivariable model, only OUES was identified as the sole significant independent prognostic variable. Conclusion OUES provides an effective, independent measure of pathological exercise physiology. Its numerical value is relatively insensitive to the duration of exercise data from which it is calculated. Its prognostic value seems to be stronger than the best available existing measures of exercise physiology.
Ventilatory abnormalities during exercise in heart failure: a mini review
2007
Heart Failure (HF) is a significant health care concern with in both the United States and Europe. While there are a number of mechanisms that lead to HF, a decline in the response to exercise is common amongst the various etiologies. Cardiopulmonary exercise testing (CPET) is a well established diagnostic and prognostic tool in the HF population. This exercise testing technique allows for the measurement of oxygen consumption (VO 2 ), carbon dioxide production (VCO 2 ) and minute ventilation (VE) across time. Cardiovascular and skeletal muscle dysfunction is considered central to the often abnormal exercise response observed in the HF population. As such, VO 2 at peak exercise is the most recognized CPET variable in patients with HF. In recent years however, the importance of assessing VE during exercise, either alone or in combination with expired gases, has been highlighted in a number of investigations. The VE-VCO 2 relationship, exercise periodic breathing (EPB) and the oxygen uptake efficiency slope (OUES) are, to this point, the most studied CPET measurements incorporating VE in the HF population. Of these, the VE-VCO 2 relationship has received the greatest amount of attention. This review will address the clinical significance of these CPET measurements in the HF population.
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.
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)