Cardiopulmonary exercise testing is equally prognostic in young, middle-aged and older individuals diagnosed with heart failure

Background: Previous research has demonstrated the prognostic value of cardiopulmonary exercise testing (CPX) in elderly patients with heart failure (HF). Investigations that have comprehensively examined the value of CPX across different age groups are lacking. The purpose of the present investigation was to evaluate the prognostic value of CPX in young, middle-aged and older patients with HF. Methods: A total of 1605 subjects (age: 59.2 +/- 13.7 years, 78% male) underwent CPX and were subsequently tracked for major cardiac events. Ventilatory efficiency (VE/VCO(2) slope) and peak oxygen consumption (VO(2)), both absolute and percent-predicted, were determined. The prognostic value of these CPX variables was assessed in <= 45, 46-65 and >= 66 year subgroups. Results: The three year event rates for major cardiac events in the <= 45, 46-65 and >= 66 year subgroups were 8.8%, 6.0% and 5.7%, respectively. The VE/VCO(2) slope (Hazard ratio >= 1.07, p<0.001), peak VO(2) (Hazard ratio <= 0.87, p<0.001) and percent-predicted peak VO(2) (Hazard ratio <= 0.98, p<0.001) were all significant prognostic markers in each age subgroup. While the VE/VCO(2) slope carried the greatest prognostic strength, peak VO(2) and percent-predicted peak VO(2) were retained in multivariate analyses (Residual Chi-Square >= 5.2, p<0.05). With respect to peak VO(2), the actual value was the more robust prognostic marker in the <= 45 and >= 66 year subgroups while the percent-predicted expression provided better predictive resolution in subjects who were 46-65 years old. Conclusions: These results indicate that, irrespective of a patient's age at presentation, CPX provides valuable prognostic information in the HF population.