A method for determining exercise oscillatory ventilation in heart failure: Prognostic value and practical implications

摘要

Abstract Background Exercise oscillatory ventilation (EOV) has been shown to be a powerful prognostic marker in chronic heart failure (CHF). However, EOV is poorly defined, its measurement lacks standardization and it is underutilized in clinical practice. The purpose of this pilot study was to investigate the prognostic value of a modified definition of EOV in patients with CHF. Methods Eighty-nine CHF patients (56.5±8.4years) (64% NYHA class III-IV) underwent cardiopulmonary exercise testing. EOV was defined as meeting all the following criteria: (1) ≥3 consecutive cyclic fluctuations of ventilation during exercise; (2) average amplitude over 3 ventilatory oscillations ≥5L; and (3) an average length of three oscillatory cycles 40s to 140s. Adverse cardiac events were tracked during 28±19months follow up. Cox proportional hazard analysis was used to determine the association between cardiac events and EOV. Results Forty-eight patients (54%) met all three criteria and were determined to have EOV. These patients exhibited significantly increased risk for adverse cardiac events [hazard ratio=2.2, 95% CI (1.2 to 4.1), p=0.011] compared to patients without EOV. After adjusting for age and established prognostic covariates (peak VO 2 and V E /VCO 2 slope), the modified EOV definition was the only significant variable in the multivariate model [hazard ratio=2.0, 95% CI (1.1 to 3.7), p=0.035]. Conclusions The proposed method for determining EOV was independently associated with increased risk for adverse cardiac events in CHF patients. While larger prospective studies are needed, this definition provides a relatively simple and more objective characterization of EOV, suggesting its potential application in clinical practice.