Physiological parameters during the initial stages of cardiopulmonary exercise testing in patients with chronic heart failure. Their value in the assessment of clinical severity and prognosis.

AIMS

To analyse the relationship between initial exercise parameters and peak oxygen consumption and prognosis in 96 patients with congestive heart failure.

METHODS AND RESULTS

Comparison of responses during the initial 6 min of cardiopulmonary exercise testing (Naughton modified protocol) in patients stratified to the Weber classification, and analysis of their predictive value with respect to peak oxygen uptake and prognosis. All patients had a left ventricular ejection fraction < 0.45 and a valid cardiopulmonary exercise test, during which they remained in sinus rhythm. Significant differences in several parameters were seen in the initial stages, including oxygen pulse (P < 0.04) and ventilation equivalent for oxygen (P < 0.004). These parameters remained as independent predictors of peak oxygen uptake in the algorithm derived from baseline and initial stage variables. In a multivariate Cox proportional hazards model, the predicted peak oxygen uptake (P < 0.003) was an independent predictor of mortality.

CONCLUSION

In patients with congestive heart failure, the initial 6 min parameters of a cardiopulmonary exercise test have additional value in the assessment of clinical severity and prognosis. This may be of clinical relevance since a limited incremental exercise protocol may be more objective than more traditional 6 min walking tests and less demanding.