BACKGROUND: Although parameters obtained during submaximal exercise are known to be useful for predicting mortality in cardiac patients, it has been a matter of debate whether the submaximal parameters are superior to peak oxygen uptake (VO(2)). For this purpose, we aimed to determine the best index among exercise variables in predicting long-term mortality in patients with chronic heart disease. METHODS: The study population consisted of 385 consecutive patients with chronic heart disease who performed a symptom-limited incremental exercise test on a cycle ergometer. Breath-by-breath respiratory gas analysis was used to estimate the peak VO(2), the ratio of the increase in VO(2) to the increase in work rate (WR) [VO(2)/Delta WR], and the ratio of the increase in minute ventilation E to the increase in carbon dioxide output (VCO(2)) [Delta VE/Delta VCO(2)]. RESULTS: After 1,899 +/- 495 days of follow-up (mean +/- SD), 33 cardiovascular-related deaths occurred. Nonsurvivors achieved lower peak VO(2), lower VO(2)/Delta VWR, and higher Delta VE/Delta VCO(2) compared to the survivors. In the univariate Cox proportional hazards analysis, peak VO(2), VO(2)/Delta VWR, and Delta VE/Delta VCO(2) were found to be significant prognostic indexes of survival. However, multivariate analysis revealed O(2)/Delta VWR as an independent predictor of mortality and Delta VE/delta VCO(2) as a slightly weaker predictor. In this analysis, the prognostic power of peak O(2) was insignificant. CONCLUSION: Submaximal respiratory gas indexes are very likely to be more sensitive than peak VO(2) for predicting poor survival in ambulatory patients with chronic heart disease.
BACKGROUND: Although parameters obtained during submaximal exercise are known to be useful for predicting mortality in cardiac patients, it has been a matter of debate whether the submaximal parameters are superior to peak oxygen uptake (VO(2)). For this purpose, we aimed to determine the best index among exercise variables in predicting long-term mortality in patients with chronic heart disease. METHODS: The study population consisted of 385 consecutive patients with chronic heart disease who performed a symptom-limited incremental exercise test on a cycle ergometer. Breath-by-breath respiratory gas analysis was used to estimate the peak VO(2), the ratio of the increase in VO(2) to the increase in work rate (WR) [VO(2)/Delta WR], and the ratio of the increase in minute ventilation E to the increase in carbon dioxide output (VCO(2)) [Delta VE/Delta VCO(2)]. RESULTS: After 1,899 +/- 495 days of follow-up (mean +/- SD), 33 cardiovascular-related deaths occurred. Nonsurvivors achieved lower peak VO(2), lower VO(2)/Delta VWR, and higher Delta VE/Delta VCO(2) compared to the survivors. In the univariate Cox proportional hazards analysis, peak VO(2), VO(2)/Delta VWR, and Delta VE/Delta VCO(2) were found to be significant prognostic indexes of survival. However, multivariate analysis revealed O(2)/Delta VWR as an independent predictor of mortality and Delta VE/delta VCO(2) as a slightly weaker predictor. In this analysis, the prognostic power of peak O(2) was insignificant. CONCLUSION: Submaximal respiratory gas indexes are very likely to be more sensitive than peak VO(2) for predicting poor survival in ambulatory patients with chronic heart disease.
Authors: Ross Arena; Dean MacCarter; Thomas P Olson; Sophie Lalande; Maile L Ceridon; Lyle J Olson; Bruce Johnson Journal: J Card Fail Date: 2009-02-10 Impact factor: 5.712
Authors: Ahmad Sabbahi; Richard Severin; Cemal Ozemek; Shane A Phillips; Ross Arena Journal: Expert Rev Respir Med Date: 2020-01-03 Impact factor: 3.772