Left atrioventricular coupling index (LACI), an index coupling left atrial to left ventricular (LV) volume at end-diastole, has been shown to be associated with prognosis in different clinical settings. However, the relation between LACI and LV diastolic dysfunction (DD) remains to be established. The aims of the present study were to investigate the association between LACI and LV DD and to assess its prognostic value in patients with heart failure (HF).

A total of 1,158 patients with HF in stable condition, on optimal medical therapy, were retrospectively analyzed (derivation cohort). Clinical and echocardiographic features were characterized across LACI tertiles. The independent prognostic value of LACI (end point: all-cause death or HF hospitalization) was assessed using Cox regression. Results were validated in an external cohort of 242 patients with HF.

In the derivation cohort, the median LACI value was 0.29 (interquartile range, 0.19-0.42). Patients in the third tertile (LACI > 0.36) were older and presented with more advanced HF symptoms. Although the prevalence of grade 1 DD (American Society of Echocardiography/European Association of Cardiovascular Imaging classification) progressively decreased across LACI tertiles, the prevalence of grade 3 DD significantly increased (8%, 23%, and 46%, respectively; P < .0001). A cutoff value of ≥0.26 identified moderate to severe DD with an area under the curve of 0.75. During follow-up (median, 28 months; interquartile range, 11-53 months), 407 patients (35%) reached the end point. On multivariable analysis, LACI was independently associated with outcomes (hazard ratio for a 1-SD increase, 1.16; 95% CI, 1.06-1.28; P = .002), showing incremental predictive value over the DD grading system (net reclassification improvement = 0.150, P < .0001). The prognostic value of LACI was consistent in the external validation cohort.

LACI is associated with DD severity and is an independent predictor of outcomes in patients with HF.

Association among LACI, DD, and prognosis in patients with HF. The figure summarizes the main findings of the present study. The top left panel illustrates how LACI can be assessed on conventional echocardiography. The top right panel shows the association between LACI and LV DD. The bottom left panel (unadjusted) and bottom right panel (adjusted) show the association between LACI and outcomes in patients with HF. EDV, End-diastolic volume.