Predicting survival probability for major congestive heart failure events in patients attaining a low peak respiratory exchange ratio during cardiopulmonary exercise testing

Many congestive heart failure (CHF) patients may not be able to attain a peak respiratory exchange ratio (RERpeak) >1.10 during maximal cardiopulmonary exercise (CPX) testing. Although this is usually attributed to a submaximal effort, a portion of this population may not be able to attain this RERpeak level due to pathophysiological complications of heart failure. Currently, little is known about the predictive value of CPX testing in CHF patients with a RERpeak 34, LVEF 1.10) group within the same V.O2peak stratum. Exploratory multivariate proportional hazard analysis in this particular group revealed that no use of beta-blockers, V.E/V.CO2 slope >45, LVEF <25% and ischemic etiology of CHF were the significant independent predictors of CHF-related events