Left atrioventricular coupling index measured by echocardiography in heart failure with preserved ejection fraction

Abstract

Heart failure (HF) is a global health burden, with high hospitalization and mortality rates. Timely diagnosis is crucial in the management of HF. While noninvasive imaging techniques generally assess changes in the left atrium (LA) or left ventricle (LV) alone, the application of physiological connections between these chambers as echocardiographic parameters, such as the left atrioventricular coupling index (LACI), may be valuable as an early marker of HF. We conducted a cross-sectional study in which 1145 Vietnamese individuals were selected and 160 subjects met the inclusion criteria. These participants were divided into patient and healthy control groups, with 60 HF patients. LACI levels were significantly greater in HF patients, especially those with preserved ejection fraction (HFpEF), than in those with reduced ejection fraction (HFrEF) and controls (59.16 ± 17.94% vs. 41.28 ± 15.27% and 13.15 ± 3.92%, respectively). The LACI showed strong diagnostic value for HFpEF, with an area under the curve (AUC) of 0.951 and an optimal threshold of 33.07 (sensitivity: 97.1%, specificity: 87.3%). Multivariate analysis confirmed LACI as an independent predictor of HFpEF (OR = 1.144, 95% CI 1.087-1.205). Overall, LACI has emerged as an accessible, promising tool for diagnosing HFpEF.

Keywords: Echocardiography; Heart failure with preserved ejection fraction; Heart failure with reduced ejection fraction; Left atrioventricular coupling index.

Fig. 1

Measurement of the LAEDV and LVEDV via the biplane method to calculate the LACI index via two-dimensional echocardiography. In cases where an electrocardiogram is not simultaneously recorded during echocardiography or when it is difficult to identify the cardiac cycle during LACI measurement, the LAEDV can be considered the smallest LA volume, and the LVEDV can be considered the largest LV volume. Panel A: Measurement of the LV volume in the apical four-chamber view. Panel B: Measurement of the LV volume in the apical two-chamber view. Panel C: Measurement of LA volume in the apical four-chamber view. Panel D: Measurement of LA volume in the apical two-chamber view.

Fig. 2

Heatmap illustrating the relationships between echocardiographic parameters. The color of each cell corresponds to the magnitude and direction of the correlation coefficient, with blue indicating a positive correlation and red indicating a negative correlation. The numerical values within the cells represent the two-way correlation coefficient. NT-proBNP, N-terminal pro–B-type natriuretic peptide; LAVI, left atrial volume index; LVMI, left ventricular mass index; LV EF, left ventricular ejection fraction; E/A, ratio of early to late diastolic filling velocities; e’ lateral, lateral early diastolic mitral annular velocity; e’ septal, septal early diastolic mitral annular velocity; E/e’ ratio, average ratio of early diastolic mitral inflow velocity to early diastolic mitral annular velocity; TRV, maximum tricuspid regurgitant velocity; LV GLS, left ventricular global longitudinal strain; LASr, left atrial reservoir strain; LAScd, left atrial conduit strain; LASct, left atrial contractile strain; LACI, left atrioventricular coupling index.

Fig. 3

ROC curves of LASr, LAScd, LACI, and LAVI for diagnosing HFpEF. LAVI, left atrial volume index; LASr, left atrial reservoir strain; LAScd, left atrial conduit strain; LACI, left atrioventricular coupling index.

Fig. 4

Bland-Altman plot with marginal histograms for interobserver and intraobserver agreement in assessing the reliability of LACI measurement. Panel A: Intraobserver variability of LACI. Panel B: Interobserver variability of LACI. Bias, mean of differences between the two experts, Upper LoA, upper level of limits of agreement = mean of differences + 1.96 standard deviations; Lower LoA, lower level of limits of agreement = mean of differences − 1.96 standard deviations; r, Pearson correlation coefficients; ICC, Intraclass correlation coefficient; SEM, standard error of measurement.