Aims: Amino-terminal portion of pro-B-type natriuretic peptide (NT-pro-BNP) is a valuable diagnostic and prognostic marker in congestive heart failure (CHF). In CHF patients, elevation of natriuretic peptide levels correlate with decreased left ventricular (LV) ejection fraction (EF) and increased left atrial (LA) volumes, but a correlation with LA function that is a determinant of haemodynamic and clinical status in CHF with independent prognostic value has never been investigated. Aim of this study was to evaluate the relationship between cardiac neurohormonal activation and LA function in patients with CHF due to dilated cardiomyopathy.
Methods and results: One hundred and one patients (86% males; mean age, 64 ± 11 years) with dilated ischaemic or non-ischaemic cardiomyopathy, LV EF ≤45% (mean LV EF, 33 ± 8%), and New York Heart Association class II-IV underwent transthoracic echocardiography to evaluate LA fractional active and total emptying from M- and B-Mode images, and, on the same day, venous blood sample collection to dose NT-pro-BNP. By univariate analyses, NT-pro-BNP significantly correlated to age, LA dimensions, LA function indexes, EF, and functional class. At multivariate analysis, LV EF and M- or B-Mode indexes of LA function were the only independent predictors of NT-pro-BNP values. A NT-pro-BNP cut-off of 1480 pg/mL identified LA dysfunction with 89% specificity and 54% sensitivity.
Conclusion: In CHF patients with severely impaired systolic function, NT-pro-BNP levels reflect LA and LV dysfunction. These data should prompt studies to investigate the relationship between changes of LA function and NT-pro-BNP levels and their clinical value as prognostic and therapeutic targets in CHF.