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

Vainshelboim B, Amin A, Christle JW, Hebbal S, Ashley EA, Myers J

Int J Cardiol. 2017 Dec 15;249:287-291. doi: 10.1016/j.ijcard.2017.09.028. Epub
2017 Sep 14.

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 VO2 and VE/VCO2 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.