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

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Aarti Kenjale (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/
Advisor
Paul Davis

Abstract: 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 <1.10. Hence, the purpose of this study was to identify significant predictors of CHF-related adverse events in patients with a low RERpeak. The variables analyzed for predicting two-year survival of CHF-related events included V.E/V.CO2 slope, left ventricular ejection fraction (LVEF), etiology of CHF, beta-blocker usage, age, sex and body mass index (BMI). No use of beta-blockers, V.E/V.CO2 slope >34, LVEF <25%, and ischemic etiology of CHF were associated with significantly lower two-year CHF-related event-free survival probability within the V.O2peak <14 ml/kg/min stratum. This probability was comparable to the high RERpeak (>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.

Additional Information

Publication
Thesis
Language: English
Date: 2008
Keywords
Cardiopulmonary Exercise Testing, Respiratory Exchange Ratio, Congestive heart failure, Heart transplantation, Beta-blocker, VE/VCO2 slope
Subjects
Congestive heart failure $x Pathophysiology.
Exercise tests.
Pulmonary gas exchange.
Adrenergic beta blockers.