The value of cardiopulmonary exercise testing and brain natriuretic peptide plasma levels in predicting the prognosis of patients with chronic heart failure

Abstract

Background A peak VO 2 above 14 ml/min/kg at cardiopulmonary exercise testing and brain natriuretic peptide (BNP) levels is used to estimate survival in patients with chronic heart failure (CHF). Limited data, however, exist comparing the prognostic value of both markers simultaneously in patients with mild to moderate CHF. Methods We prospectively studied 85 consecutive patients (59 ± 13 years, 63 men) with CHF (mean LVEF 26 ± 6%). All patients underwent cardiopulmonary exercise testing with determination of peak VO 2 and measurement of plasma BNP at rest. The incidence of cardiac decompensation and cardiac death was recorded in the follow-up. Results During a mean follow-up of 427 ± 150 days, four deaths and ten cardiac decompensations occurred. Kaplan–Meier estimates of freedom from clinical events differed significantly for patients above and below the median BNP of 292 pg/ml and also for patients above and below a peak VO 2 of 14 ml/min/kg ( p < 0.05 each). BNP and peak VO 2 (area under the ROC 0.75 vs. 0.72) showed a comparable discrimination of CHF patients with adverse cardiac events. The prognostic information of BNP was at least as powerful as that derived from peak VO 2. A BNP above 324 pg/ml was associated with a risk ratio of 8.8 for adverse cardiac events. Conclusions In patients with mild to moderate CHF, BNP measurements appear to be an alternative to peak VO 2 determined by cardiopulmonary exercise testing for the assessment of prognosis in CHF. BNP may facilitate the ambulatory management of patients with mild to moderate CHF since it is less expensive, less time-consuming, and free of procedural risk compared to exercise testing.