Incremental value of N-terminal pro-brain natriuretic peptide over left ventricle ejection fraction and aerobic capacity for estimating prognosis in heart failure patients.

Background: N-terminal pro-brain natriuretic peptide (NT-proBNP) plasma levels have been associated with indices of left ventricular (LV) function and aerobic capacity in heart failure.

Methods: We prospectively followed-up 149 patients with impaired left ventricular function for 30 +/- 10 months. During this period, 22 patients died and 5 underwent heart transplantation. Blood samples for NT-proBNP assessment were taken at baseline and before cardiopulmonary exercise to estimate peak oxygen consumption (Vo(2)). LV cavity diameter, left atrial size and LV ejection fraction (LVEF) were measured by echocardiography.

Results: NT-proBNP plasma levels >1,164 pg/ml showed 85% sensitivity and 82% specificity for detecting Vo(2)<14 ml/kg/min (area under the curve [AUC] = 90%, p < 0.001). Patients above this cutoff showed a 13.6-fold greater hazard ratio compared with those with values below this cutoff (p < 0.001). NT-proBNP plasma levels of >760 pg/ml showed 77% sensitivity and 69% specificity for detecting LVEF <28% (AUC = 77%, p < 0.001). Patients with values above this cutoff showed a 15.85-fold greater hazard ratio compared to those with values below this cutoff (p < 0.001). The addition of NT-proBNP to an assessment model that includes peak Vo(2), LVEF and New York Heart Association (NYHA) classification can significantly improve predictive ability.

Conclusions: Assessment of NT-proBNP should be performed to detect candidates for heart transplantation because of the useful prognostic information that it can provide.