Abstract 17081: Predicting Outcomes Using an Algorithm Based on Percent Predicted VO2 and Ventilatory Class in Patients With HFrEF: Data From the HF-ACTION Study
Introduction: Despite numerous prognostic variables from a cardiopulmonary exercise (CPX) test, estimating absolute risk that is clinically-relevant among patients with heart failure (HF) remains a challenge.
Purpose: Validate a simple and clinically-actionable, risk stratification algorithm for patients with HF with reduced ejection fraction (HFrEF) based on % predicted oxygen uptake (ppVO2) and ventilatory class (VC; i.e., categories of VE/VCO2 slope) using data from the HF-ACTION (Heart Failure: A Controlled Trial Investigating Outcomes of Exercise TraiNing) study.
Methods: A 5 category risk stratification algorithm (endpoint= all-cause mortality) based on a combination of ppVO2 and VC was previously developed on patients with HFrEF (n= 1,113; EF<40%; 33% female; age= 54±13 y) who had a CPX test at Henry Ford Hospital. Kaplan-Meier (KM) survival curves, life tables, and Cox regression adjusted for the MAGGIC (Meta-Analysis Global Group in Chronic Heart Failure) risk score were used to assess the relationship between the Henry Ford risk categories and time to all-cause mortality/hospitalization in the HF-ACTION cohort.
Results: Among 2,063 HF-ACTION subjects, complete data was available on 1,757 (EF=25±7%; 17% female; age=59±13 y). During 1.5±1.2 y (mean±sd) of follow-up, there were 1,195 (68%) events. Based on KM estimates, there was significant variation (χ2=126; p<.001) in unadjusted events rates between risk categories. As shown in the Table, compared to the lowest risk group, each of the remaining categories were associated with significantly greater adjusted risk for the endpoint.
Conclusion: The combination of ppVO2 and VC can be used to simply and effectively risk-stratify patients with HFrEF into categories that a clinician might consider for clinical decision making.
Author Disclosures: C.A. Brawner: None. D.E. Lanfear: None. J.K. Ehrman: None. S.J. Keteyian: None.
- © 2016 by American Heart Association, Inc.