The correlation of left atrial volume index to the level of N-terminal pro-BNP in heart failure with a preserved ejection fraction.

BACKGROUND: Patients with heart failure with a preserved ejection fraction (HFPEF) have high N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) level and a high ratio of early transmitral inflow to diastolic velocity of the mitral annulus (E/E') derived from tissue Doppler imaging (TDI). Because left atrial volume indexed to body surface area (LAVI) is believed to reflect chronic diastolic dysfunction, we assessed the ability of LAVI and E/E' ratio to predict NT-pro-BNP level in patients with HFPEF.
METHODS: One hundred forty-eight patients with HFPEF (ejection fraction >or= 50%, NT-pro-BNP >or= 100 pg/ml) underwent conventional echocardiography including LAVI and E/E' ratio, which were compared with NT-pro-BNP level.
RESULTS: In the overall patient population, modest correlations were found between NT-pro-BNP level and peak systolic TDI (S') (P = 0.009), LAVI (P = 0.009), and E/E' ratio (P = 0.017). However, in patients with E/E' ratio >or=13, LAVI was the most important predictor of NT-pro-BNP level (P < 0.001), whereas in those with E/E' ratio <13 it was S' (P < 0.001) in multivariate analysis.
CONCLUSION: In patients with HFPEF evidenced by high NT-pro-BNP level, LAVI correlates with NT-pro-BNP level in the setting of elevated E/E' ratio. However, in the setting of low E/E' ratio, LAVI does not seem to be associated with NT-pro-BNP level.