Prognostic characteristics of cardiopulmonary exercise testing in heart failure: comparing American and European models.

BACKGROUND: Cardiopulmonary exercise testing (CPET) in the heart failure population is a standard of care in both American and European clinics, although the mode of exercise typically differs. The purpose of the present study was to compare the prognostic characteristics of peak oxygen consumption (VO2) and the minute ventilation-carbon dioxide production (VE/VCO2) slope between two independent heart failure groups.

DESIGN AND METHODS: One hundred and two subjects underwent maximal exercise CPET using bicycle ergometry at San Paolo Hospital in Milan, Italy (SPH) and 105 subjects underwent treadmill CPET at Virginia Commonwealth University in Richmond, Virginia (VCU). Subjects were tracked for cardiac-related mortality for a 1-year period after CPET.

RESULTS: There were 13 cardiac-related deaths over the 1-year tracking period in both groups. Optimal prognostic threshold values for peak VO2 were 12.9 ml O2/kg per min (sensitivity 81%, specificity 69%) in the SPH group and 12.0 ml O2/kg per min (sensitivity 74%, specificity 69%) in the VCU group. An optimal prognostic threshold value for the VE/VCO2 slope was 34.4 in the SPH (sensitivity 61%, specificity 85%) and 34.5 in the VCU (sensitivity 64%, specificity 93%) groups.

DISCUSSION: The prognostic characteristics of peak VO2 and the VE/VCO2 slope were similar between the two centers. These results suggest that the mode of exercise does not greatly impact the prognostic utility of CPET responses in heart failure. They further suggest that prognostic guidelines for the application of CPET in heart failure may be applied globally, irrespective of differences in testing modality.