Left Atrioventricular Coupling Index for Predicting Adverse Cardiac Outcomes in Patients with Ischemic Cardiomyopathy

Abstract

Background: Risk stratification in ischemic cardiomyopathy (ICM) traditionally relies on ventricular parameters like left ventricular ejection fraction (LVEF), which may not fully demonstrate the complex interplay between atrial and ventricular remodelling. The left atrioventricular coupling index (LACI) has emerged as a promising integrative marker. This study evaluated the prognostic value of cardiovascular magnetic resonance (CMR)-derived LACI in patients with ICM. Methods: This retrospective cohort study included 276 patients with ICM who underwent CMR between 2015 and 2024. LACI was calculated as LAEDV/LVEDV. The primary endpoint was a composite of cardiovascular mortality, non-fatal myocardial infarction, heart failure hospitalization (HFH), and major ventricular arrhythmic events. Optimal LACI cut-off values were determined using receiver operating characteristic (ROC) analysis. Results: During a median follow-up of 3.2 years, the primary endpoint occurred in 100 patients (36.2%). The optimal LACI cut-off for predicting the primary outcome was 0.35. Patients with LACI ≥ 0.35 had a significantly higher incidence of the primary outcome compared to those below the threshold (52.3% vs. 31.3%; p = 0.002). In multivariate Cox regression analysis, LACI ≥ 0.35 was an independent predictor of the primary outcome (adjusted HR 1.83; 95% CI 1.06–3.16; p = 0.029). Among secondary outcome, LACI ≥ 0.35 was strongly associated with HFH (aHR 3.33; 95% CI 1.58–6.72; p < 0.001), though it did not reach statistical significance for all-cause or cardiovascular mortality. Conclusions: CMR-derived LACI is an independent predictor of adverse cardiovascular outcomes, particularly HFH, in patients with ICM. While its standalone diagnostic accuracy is modest, LACI provides incremental prognostic value beyond traditional metrics like LVEF.