Abstract 14036: An Algorithm to Guide Prognosis Based on the Combination of Peak VO2 and VE-VCO2 slope in Patients with HFrEF: The Henry Ford HospITal CardioPulmonary EXercise Testing (FIT-CPX) Project
Many studies have reported the prognostic significance of peak oxygen consumption (VO2) and VE-VCO2 slope in patients with heart failure (HF). However, there are limited data stratifying risk based on a combination of these measures and how to best use them.
Purpose: Describe 1 and 3-y event rates for the composite endpoint of mortality, left ventricular assist device (LVAD), or cardiac transplant (CT) based on the combined evaluation of peak VO2 and VE-VCO2 slope in patients with HF with reduced ejection fraction (≤ 40%; HFrEF).
Methods: Patients (n= 1,116; 33% female; age= 54 ± 13 y) with a cardiopulmonary exercise test between 1997 and 2010 and confirmed HFrEF were identified. Endpoint data was obtained through 2011. Patients were grouped based on peak VO2 (< 12, 12 to18, and > 18 mL/kg/min) and (VE-VCO2 slope ≥ 34 or < 34). Cumulative events were identified from life tables. Cox regression with adjustment for age, gender, ejection fraction, and beta-blocker therapy was used to calculate the hazard ratio for VE-VCO2 slope ≥ 34 within each peak VO2 group.
Results: The 1 and 3-y event rates are shown in the Table. Among patients with a peak VO2 < 12, 1 and 3-y events were 23% and 44%, respectively. Within this group, VE-VCO2 slope ≥ 34 represented more than twice the risk at both 1 y (HR 2.42, 95% CI 1.09, 5.38) and 3 y (HR 2.32, 95% CI 1.33, 4.05). Among patients with a peak VO2 12 to 18, 1 and 3-y events were 14% and 30%, respectively. Within this group, a VE-VCO2 slope ≥ 34 was associated with increased risk at both 1 y (HR 1.80, 95% CI 1.13, 2.87) and 3 y (HR 1.80, 95% CI 1.30, 2.50). Among patients with peak VO2 > 18, 1 and 3-y events were 2% and 10%, respectively, and VE-VCO2 slope was not statistically associated with increased risk.
Conclusion: Among patients with a peak VO2 ≤ 18, VE-VCO2 slope ≥ 34 further refines the risk for a composite endpoint of mortality, LVAD, or CT at both 1 and 3 y.
Author Disclosures: C.A. Brawner: None. A. Shafiq: None. H.A. Aldred: None. R. Hassan: None. S. Vasko: None. J.K. Ehrman: None. Y. Selektor: None. C. Tita: None. M. Velez: None. C.T. Williams: None. D.E. Lanfear: None. S.J. Keteyian: None.
- © 2014 by American Heart Association, Inc.