Incremental predictive power of B-type natriuretic peptide and tissue Doppler echocardiography in the prognosis of patients with congestive heart failure

OBJECTIVES This study was designed to determine how novel indexes of left ventricular (LV) filling pressure-transmitral early diastolic velocity/tissue Doppler mitral annular early diastolic velocity (E/Ea) and B-type natriuretic peptide (BNP)-compare to conventional predictors of outcome in patients with congestive heart failure (CHF). BACKGROUND It is known that E/Ea can predict LV filling pressure in patients with cardiac disease, including, in contrast to conventional Doppler indexes, in normal ejection fraction. B-type natriuretic peptide has also been correlated to LV filling pressure, but appears to provide more global cardiac information than E/Ea. It is unknown, however, how these novel indexes compare to conventional predictors of CHF patient outcome. METHODS A total of 116 consecutive patients hospitalized with CHF underwent simultaneous clinical assessment, BNP, and comprehensive echo-Doppler study once ready for discharge. The ability of these variables to determine the primary end point (cardiac death or rehospitalization for CHF) was determined. RESULTS Follow-up was complete on 110 of 116 patients at a mean of 527 days after hospital discharge. There were 54 patients (50%) with the primary end point (37 re-hospitalizations for CHF and 17 cardiac deaths). On Cox univariate analysis, E/Ea (chi-square = 13.6, p = 0.0001) and BNP (chi-square = 17.0, p < 0.0001) were significant predictors of the primary end point. In stepwise analysis, BNP >= 250 pg/ml and mitral E/Ea >= 15 had incremental predictive power (chi-square = 23.1, p for increment = 0.02), to which conventional predictors did not add further prognostic information. CONCLUSIONS In patients admitted to hospital with CHF, pre-discharge BNP and E/Ea are incremental predictors of outcome, to which conventional predictors do not significantly add.