Introduction: Determination of exercise oscillatory ventilation (EOV) is subjective and the inter-reviewer agreement has not been reported. The purpose of this study was, among patients with heart failure (HF): (1) determine the inter-reviewer agreement for EOV; and (2) describe a novel, objective, and quantifiable measure of EOV.
Methods: This was a secondary analysis of the HEART Camp: Promoting Adherence to Exercise in Patients with Heart Failure study. EOV was determined through a blinded review by 6 individuals based on their interpretation of the EOV literature. Inter-reviewer agreement was assessed with Fleiss kappa ([kappa]). Final determination of EOV was based on agreement by 4 of the 6 reviewers. A new measure (ventilation dispersion index; VDI) was calculated for each test and its ability to predict EOV was assessed with the receiver operator characteristics curve (ROC).
Results: Among 243 patients with HF (age=60+/-12 years; 45% women) the inter-reviewer agreement for EOV was fair ([kappa]=0.303) with 10-s discrete data averages and significantly better, but only moderate ([kappa]= 0.429) with 30-s rolling data averages. Prevalence of positive and indeterminate EOVs were 18% and 30% with the 10-s discrete averages and 14% and 13% with the 30-s rolling averages, respectively. VDI was strongly associated with EOV with area under the ROC= 0.852 to 0.890.
Conclusions: Inter-reviewer agreement for EOV in patients with HF is fair to moderate which can negatively affect risk stratification. VDI has strong predictive validity with EOV; as such it might be a useful measure of prognosis in patients with HF.
(C) 2017 American College of Sports Medicine