The Correlation of Left Atrial Volume Index to the Level of N-Terminal Pro-BNP in Heart Failure with a Preserved Ejection Fraction

Abstract

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 ≥ 50%, NT- pro-BNP ≥ 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 ≥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. (ECHOCARDIOGRAPHY, Volume 25, October 2008)