The left atrium (LA) and left ventricle (LV) parameters have both a good prognostic value for CV events when they are taken separately. Based on the close physiological interactions between LA and LV, we hypothesise the simultaneous assessment of the left atrioventricular coupling could be even more accurate to predict CV events.

This study aimed to investigate the prognostic value of a novel left atrioventricular coupling index (LACI) and to assess its predictive value for CV events.

A total of 4124 participants in the Multi-Ethnic Study of Atherosclerosis (MESA) underwent a cardiac MRI study. The LACI by cardiac MRI was defined by the ratio of the indexed LA end-diastolic volume divided by the indexed LV end-diastolic volume. Cox proportional hazard models were constructed to predict the endpoints of atrial fibrillation (AF), heart failure (HF), hard CV events, and CV death. In univariable and multivariable Cox analyses, the association between LACI or all other LA and LV variables and time-to-event was analysed, adjusting for after adjustment for established risk factors and biomarkers.

A total of 1151 (27.9%) CV events were observed during a median (IQR) follow-up period of 15.9 (12.9–16.6) years. In univariate analysis, LACI was associated with AF (HR: 2.13, 95% CI [1.97–2.31]), heart failure (HR: 1.70, 95% CI [1.56–1.86]), hard CV events (HR: 1.35, 95% CI [1.25–1.46]) (Fig. 1), and CV death (HR: 1.53, 95% CI [1.38–1.70]; for all P<0.0001). In Cox multivariate analysis, LACI had a significant independent predictive value for AF (HR: 1.86, 95% CI [1.69–2.04]), heart failure (HR: 1.45, 95% CI [1.31–1.61]), hard CV events (HR: 1.20, 95% CI [1.10–1.31]), and CV death (HR: 1.28, 95% CI [1.14–1.44]; for all P<0.0001). For hard CV events, C-statistic for LACI (0.65) was greater than LVGFI (0.63), LAVI_min (0.61), LA strain (0.59), or LVEF (0.55) (Fig. 1).

The LACI is a powerful predictor of incident HF, AF, hard CV events, and CV death.