Comparison of ventilatory expired gas parameters used to predict hospitalization in patients with heart failure.
BACKGROUND
Several ventilatory expired gas measures obtained during exercise testing demonstrate prognostic value in the heart failure (HF) population. Comparison of prognostic efficacy between pertinent measures is sparse.


METHODS
The ability of various expressions of peak oxygen consumption (VO2), the relationship between minute ventilation (VE) and carbon dioxide production (VCO2), and the partial pressure of end-tidal carbon dioxide (P(ET)CO2) were assessed to determine which measure(s) best predicted cardiac-related hospitalization over a 1-year period in subjects diagnosed with HF.


RESULTS
Univariate Cox regression analysis found that several expressions of peak VO 2, VE-VCO2 relationship, and P(ET)CO2 were significant predictors of hospitalization. Multivariate Cox regression analysis revealed that the VE/VCO2 slope significantly predicted hospitalization (chi2 = 29.1, P <.00001). Peak VO 2 and P(ET)CO2 did not provide additional predictive value.


CONCLUSIONS
The prognostic superiority of the VE/VCO2 slope over peak VO2 may be a result of the latter measure's partial dependence on subject effort and skeletal muscle function.
Arena
Ross
R
Department of Physical Therapy, New York University, New York, NY 10010, USA. ra56@nyu.ed
Humphrey
Reed
R
D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001944:Breath Tests; D002245:Carbon Dioxide / Q000378:metabolism*; D005080:Exercise Test; D005260:Female; D006333:Heart Failure / Q000378:metabolism / Q000503:physiopathology*; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010313:Partial Pressure; D011379:Prognosis; D012372:ROC Curve; D012044:Regression Analysis; D012119:Respiration
D002245:Carbon Dioxide