Left atrioventricular coupling and myocardial scar burden predict mortality after hospitalization for congestive heart failure, regardless of left ventricular ejection fraction

Background/Introduction Heart failure (HF) hospitalization marks a critical point in the disease trajectory and identifies patients at particularly high risk of subsequent mortality1. While left ventricular ejection fraction (LVEF) remains the cornerstone for HF classification, its prognostic ability is limited across heterogeneous HF phenotypes2. Cardiac magnetic resonance (CMR) improves HF phenotyping, but prognostic data during the critical period following a decompensated HF episode remain limited. Purpose To evaluate and compare the prognostic value of CMR-derived biomarkers, specifically the Left Atrioventricular Coupling Index (LACI) which is defined as the minimum LA volume to LV End Diastolic Volume ratio3, and myocardial scar burden (Fig1), for predicting all-cause mortality in a real-world cohort of patients hospitalized for congestive HF, irrespective of LVEF. Methods This retrospective study included 278 consecutive patients (mean age 65 ± 14 years; 66% male) hospitalized for decompensated HF who underwent CMR. Patients were stratified by LVEF (≤40%, n=198; >40%, n=80). The primary endpoint was all-cause mortality. Cox proportional hazards models were used to calculate hazard ratios (HR) and evaluate predictive model performance using Harrell’s C-index. Results Over a mean follow-up of 3.8 ± 1.7 years, 86 patients (31%) died. In multivariable Cox regression analysis, neither LVEF nor Global Longitudinal Strain (GLS) was independently associated with mortality. In contrast, LACI > 0.51 (HR 2.2, 95% CI 1.39-3.51, p<0.001) and late gadolinium enhancement (LGE) extent >2 segments (HR 1.71, 95% CI 1.12-2.61, p=0.014) were robust independent predictors of death. Incorporating LACI and LGE extent into a baseline clinical model (comprising age, diabetes, and BNP) significantly improved risk discrimination, increasing the C-index from 0.683 to 0.719 (p<0.014)(Fig2). Importantly, both LACI and LGE remained predictive across both LVEF strata (≤40% and >40%). Conclusion(s) Among patients evaluated after hospitalization for HF, LACI and myocardial scar burden are powerful, independent predictors of mortality. These CMR-derived indices provide incremental prognostic value beyond LVEF and established clinical risk factors, enhancing risk stratification across the full spectrum of heart failure phenotypes.