## Abstract

PURPOSE: While patients with heart failure who achieve a peak oxygen uptake (peak (Equation is included in full-text article.)VO _{2}) of 10 mL•kg ^{-1}•min ^{-1} or less are often considered for intensive surveillance or intervention, those achieving 14 mL•kg ^{-1}•min ^{-1} or more are generally considered to be at lower risk. Among patients in the "intermediate" range of 10.1 to 13.9 mL•kg ^{-1}•min ^{-1}, optimally stratifying risk remains a challenge. METHODS: Patients with heart failure (N = 1167) referred for cardiopulmonary exercise testing were observed for 21 ± 13 months. Patients were classified into 3 groups of peak (Equation is included in full-text article.)Vo _{2} (≤10, 10.1-13.9, and ≥14 mL•kg ^{-1}•min ^{-1}). The ability of heart rate recovery at 1 minute (HRR1) and the minute ventilation/carbon dioxide output ((Equation is included in full-text article.)E/(Equation is included in full-text article.)co _{2}) slope to complement peak (Equation is included in full-text article.)Vo _{2} in predicting cardiovascular mortality were determined. RESULTS: Peak (Equation is included in full-text article.)Vo _{2}, HRR _{1} (2 slope (>34) were independent predictors of mortality (hazard ratio 1.6, 95% CI: 1.2-2.29, P = .006; hazard ratio 1.7, 95% CI: 1.1-2.5, P = .008; and hazard ratio 2.4, 95% CI: 1.6-3.4, P <.001, respectively). Compared with those achieving a peak (Equation is included in full-text article.)Vo _{2} ≥ 14 mL•kg ^{-1}•min ^{-1}, patients within the intermediate range with either an abnormal (Equation is included in full-text article.)E/(Equation is included in full-text article.)co _{2} slope or HRR1 had a nearly 2-fold higher risk of cardiac mortality. Those with both an abnormal HRR1 and (Equation is included in full-text article.)E/(Equation is included in full-text article.)co _{2} slope had a higher mortality risk than those with a peak (Equation is included in full-text article.)Vo _{2} ≤ 10 mL•kg ^{-1}•min ^{-1}. Survival was not different between those with a peak (Equation is included in full-text article.)Vo _{2} ≤ 10 mL•kg ^{-1}•min ^{-1} and those in the intermediate range with either an abnormal HRR1 or (Equation is included in full-text article.)E/(Equation is included in full-text article.)co _{2} slope. CONCLUSIONS: HRR1 and the (Equation is included in full-text article.)E/(Equation is included in full-text article.)co _{2} slope effectively stratify patients with peak (Equation is included in full-text article.)Vo _{2} within the intermediate range into distinct groups at high and low risk.

Original language | English |
---|---|

Pages (from-to) | 141-146 |

Number of pages | 6 |

Journal | Journal of Cardiopulmonary Rehabilitation and Prevention |

Volume | 32 |

Issue number | 3 |

DOIs | |

Publication status | Published - May 2012 |

## Keywords

- cardiopulmonary exercise test
- heart failure
- mortality

## ASJC Scopus subject areas

- Rehabilitation
- Cardiology and Cardiovascular Medicine
- Pulmonary and Respiratory Medicine