Authors

1. Arena, Ross PhD, PT
2. Guazzi, Marco MD, PhD
3. Myers, Jonathan PhD
4. Chase, Paul Med
5. Bensimhon, Daniel MD
6. Cahalin, Lawrence P. PhD, PT
7. Peberdy, Mary Ann MD
8. Ashley, Euan MD
9. West, Erin MS
10. Forman, Daniel E. MD

Abstract

INTRODUCTION: While the medical management strategy for patients with heart failure (HF) has dramatically changed, cardiopulmonary exercise testing (CPX) procedures and the data obtained have remained relatively stable. We are unaware of any previous investigation that has assessed differences in the prognostic utility of CPX in HF according to time period, reflecting differences in the clinical management of systolic HF.

METHODS: Subjects (n = 381) underwent CPX between April 1, 1993, and December 31, 2005, and the remaining 511 were tested between January 1, 2006, and October 28, 2010. Peak oxygen uptake (VO₂) and the minute ventilation/carbon dioxide production (VE/VCO₂) slope were ascertained for all tests.

RESULTS: Both the VE/VCO₂ slope and peak VO₂ were strong univariate predictors of adverse events in both subgroups. In the multivariate analysis, the VE/VCO₂ slope was the strongest predictive marker while peak VO₂ added predictive value and was retained in the regression for all scenarios. In subjects undergoing CPX before 2006, a VE/VCO₂ slope 45 or greater and a peak VO₂ of less than 10 mL [middle dot] kg^-1 [middle dot] min^-1 generated a hazard ratio of 4.2 (95% CI: 1.9-9.1, P < .001) when considering only mortality as an endpoint. In subjects undergoing CPX after 2006, a VE/VCO₂ slope 45 or greater and a peak VO₂ of less than 10 mL [middle dot] kg^-1 [middle dot] min^-1 generated a hazard ratio of 8.2 (95% CI: 4.7-14.3, P < .001) when considering only mortality as an endpoint.

CONCLUSION: The results of this study indicate that CPX continues to be a valuable clinical assessment in the present-day HF management.