Comparison of plasma N-brain natriuretic peptide, peak oxygen consumption, and left ventricular ejection fraction for severity of chronic heart failure.

We investigated whether a simple blood test of plasma N-brain natriuretic peptide (N-BNP), compared with echocardiographic left ventricular ejection fraction (LVEF), both measured at rest, correlated well with aerobic exercise capacity (peak oxygen consumption [VO(2)]) in patients with chronic heart failure. Plasma N-BNP was found to significantly correlate with peak VO(2) (p <0.001) and exercise duration (p = 0.001), whereas LVEF showed very poor correlations with peak VO(2) and exercise duration (both p >0.3). The results suggest that N-BNP actually reflects functional cardiac impairment better than LVEF.