Although left atrial (LA) and left ventricular (LV) structural and functional parameters have independent prognostic value as predictors of heart failure (HF), the close physiological relationship between LA and LV suggest that the assessment of LA/LV coupling could be more accurate. To assess the prognostic value of a left atrioventricular coupling index (LACI), measured by cardiac MRI, as well as change in LACI to predict incident HF in MESA.

In the MESA, 2250 study participants, free of CV disease at baseline, had LACI assessed by CMR at baseline (Exam 1, 2000), and 10 years later (Exam 5, 2010). LACI was defined as the ratio of LA to LV end-diastolic volumes. Cox proportional hazard models were used to evaluate the associations of LACI and annualized change in LACI (ΔLACI) with HF after adjustment on traditional HF risk factors.

Among the 2250 participants (mean age 59.3±9.3 years and 48% male participants), 50 incident HF events occurred over 6.8±1.3 years after the second CMR exam. After adjustment, greater LACI and ΔLACI were independently associated with HF (adjusted HR 1.44, 95%CI [1.25–1.66] and adjusted HR 1.55, 95%CI [1.30–1.85], respectively; both P<0.0001). Adjusted models for LACI showed significant improvement in model discrimination and reclassification compared to currently used HF risk score model for predicting HF incidence (C-statistic:0.81 vs. 0.77; NRI=0.411; IDI=0.043). After adjustment, ΔLACI showed also significant improvement in model discrimination compared to the multivariable model with traditional HF risk factors for predicting incident HF (C-statistic:0.82 vs. 0.77; NRI=0.491; IDI=0.058) (Fig. 1).

In a multi-ethnic population, atrioventricular coupling (LACI) and coupling change (ΔLACI) are independently associated with incident HF. Both have incremental prognostic value for predicting HF over traditional HF risk factors.