Author + information
- Received January 2, 2013
- Revision received May 2, 2013
- Accepted May 3, 2013
- Published online October 1, 2013.
- Paul J. Chase, MEd∗,†∗ (, )
- Aarti Kenjale, MBBS, MS∗,†,
- Lawrence P. Cahalin, PhD, PT‡,
- Ross Arena, PhD, PT§,
- Paul G. Davis, PhD†,
- Jonathan Myers, PhD‖,
- Marco Guazzi, MD, PhD¶,
- Daniel E. Forman, MD#,
- Euan Ashley, MD∗∗,
- Mary Ann Peberdy, MD††,
- Erin West, MS#,
- Christopher T. Kelly, BA∗ and
- Daniel R. Bensimhon, MD∗
- ∗LeBauer Cardiovascular Research Foundation, Greensboro, North Carolina
- †Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, North Carolina
- ‡Department of Physical Therapy, Leonard M. Miller School of Medicine, University of Miami, Miami, Florida
- §Department of Physical Therapy, College of Applied Health Sciences, University of Illinois Chicago, Chicago, Illinois
- ‖Division of Cardiology, Veterans Affairs Palo Alto Health Care System, Stanford University, Palo Alto, California
- ¶Cardiology, IRCCS Policlinico San Donato, University of Milano, San Donato Milanese, Milan, Italy
- #Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts
- ∗∗Cardiovascular Medicine, Stanford University, Palo Alto, California
- ††Department of Internal Medicine, Virginia Commonwealth University, Richmond, Virginia
- ↵∗Reprint requests and correspondence:
Mr. Paul J. Chase, LeBauer Cardiovascular Research Foundation, 1200 North Elm Street, Greensboro, North Carolina 27401.
Objectives The purpose of this analysis was to evaluate the prognostic characteristics of peak oxygen consumption (Vo2) and the minute ventilation/carbon dioxide (VE/Vco2) slope of different peak respiratory exchange ratios (RERs) obtained from cardiopulmonary exercise testing in patients with heart failure (HF).
Background For patients with HF, peak Vo2 and the VE/Vco2 slope are used for assessing prognosis. Peak Vo2 is assessed in association with peak RER ≥1.10, indicating maximal effort and prognostic sensitivity. Conversely, the VE/Vco2 slope provides effort-independent prognostic discrimination.
Methods Patients with HF scheduled to undergo cardiopulmonary exercise testing were enrolled. Patients were subclassified by peak RER (RER <1.00, RER 1.00 to 1.04, RER 1.05 to 1.09, RER ≥1.10) and followed for up to 3 years for major cardiac-related events (death, left ventricular assist device implantation, or cardiac transplantation).
Results Included were 1,728 patients with HF (75% males; 40% ischemic etiology; age: 55 ± 14 years; left ventricular ejection fraction: 28 ± 10%). Two hundred seventy major events occurred, with no proportional differences across the RER subgroups. Multivariate Cox regression analysis indicated that the VE/Vco2 slope and peak Vo2 remained prognostic within each subgroup; the VE/Vco2 slope remained the strongest predictor. Receiver-operating characteristic analysis demonstrated equitable prognostic cutoffs for the VE/Vco2 slope (range: 34.9 to 35.7; area under the curve [AUC] range: 0.69 to 0.75) and peak Vo2 (range: 13.8 to 14.0 ml·kg–1·min–1; AUC range: 0.68 to 0.75).
Conclusions Peak Vo2 provided a sensitive assessment of prognosis in patients with HF in all RER subgroups. The VE/Vco2 slope provided greater prognostic discrimination in all RER subgroups. Clinical consideration may be warranted for patients with low RER, low peak Vo2, and an elevated VE/Vco2 slope.
All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received January 2, 2013.
- Revision received May 2, 2013.
- Accepted May 3, 2013.
- American College of Cardiology Foundation