Left atrial expansion index predicts left ventricular filling pressure in ischemic cardiomyopathy

The aim of the study was to assess the power of left atrial expansion index (LAEI) to predict left ventricular filling pressures and its relation with N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in patients with ischemic cardiomyopathies. This prospective study analyzed 66 patients (mean age 62 ± 11 years, range 37–89, 86.4% male) with ischemic cardiomyopathy (mean Left ventricular ejection fraction 46.4 ± 12.8%). All patients underwent transthoracic echocardiography and NT-proBNP measurement within 24 hours. The LAEI was calculated as (Vol max − Vol min) × 100%/Vol min, where Vol max was defined as maximal LA volume and Vol min was defined as minimal volume. Simple regression analysis demonstrated a significant linear correlation between LAEI and Log NT-proBNP(r = 0.723, P < 0.0001). Significant but weaker correlations were found between Log NT-proBNP and E/E’ (r = 0.504, P < 0.0001), indexed LA maximum volume (LAVI max) (r = 0.308, P = 0.012), mitral deceleration time (TDE) (r = 0.365, P = 0.003), E/A (r = 0.362, P = 0.003). Significant correlations were also found between LAEI and E/E’ (r = −0.543, P < 0.0001), LAVI max (r = 0.360, P = 0.003), E/A (r = 0.403, P = 0.001). The receiver-operating characteristic curve showed that LAEI had good diagnostic power for E/E’ > 15 at cutoff value of 66.8% with a sensitivity of 74.5% and a specificity of 83.3% while the area under the curve was of 0.875. Multivariate analysis techniques with Log-NT-proBNP as dependent variable and age, E/A, TDE, E/E’, LAVI max and LAEI as predictors, showed that the relation to LAEI was the strongest (β = −0.725). We suggest that evaluation of LAEI may be useful to predict LV filling pressures in ischemic cardiomyopathies. The power of this index exceeds that of other well-established echocardiographic parameters such as E/E’ and LVAI max.