Comparison of the prognostic value of cardiopulmonary exercise testing between male and female patients with heart failure.
BACKGROUND
Cardiopulmonary exercise testing (CPX) clearly holds prognostic value in the heart failure (HF) population. Studies investigating the prognostic value of CPX in individuals with HF have consistently examined predominantly male groups. The purpose of the present study was to examine the prognostic value of CPX in a female HF group.


METHODS
Seventy-five female and 337 male subjects diagnosed with HF participated in this study. The ability of peak oxygen consumption (VO(2)) and the minute ventilation/carbon dioxide production (VE/VCO(2)) slope to predict cardiac-related events were assessed.


RESULTS
In the year following CPX, the female group suffered 26 cardiac-related events (8 deaths/18 hospitalizations), while the male group suffered 89 cardiac-related events (20 deaths/69 hospitalizations). The hazard ratios for peak VO(2) and the VE/VCO(2) slope were 4.0 (95% confidence interval: 2.6-6.1, p<0.001) and 4.2 (95% confidence interval: 2.7-6.6, p<0.001) in the male group and 3.8 (95% confidence interval: 1.7-8.5, p<0.001) and 4.3 (95% confidence interval: 1.8-9.8, p<0.001) in the female group. In both the male and female groups, Cox multivariate analysis revealed VE/VCO(2) slope was the strongest predictor of cardiac-related events while peak VO(2) added significant predictive value and was retained in the regression.


CONCLUSION
The results of the present study indicate that the prognostic value of peak VO(2) and the VE/VCO(2) slope are similar in men and women diagnosed with HF. In both men and women, the prognostic power of the VE/VCO(2) slope is greater than that of peak VO(2).