Prognostic value of left atrioventricular coupling index for the prediction of adverse cardiac outcomes in patients with hypertrophic cardiomyopathy

Abstract Background Hypertrophic cardiomyopathy (HCM) is associated with left atrial remodeling which is associated with adverse outcomes such as death, heart failure, and atrial fibrillation (AF). The Left Atrioventricular Coupling Index (LACI) has emerged as a promising biomarker reflecting left atrial and ventricular interactions, yet its prognostic utility in HCM remains unclear. Purpose To evaluate the prognostic value of cardiac magnetic resonance imaging (CMR)-derived LACI in predicting adverse clinical outcomes in HCM patients and establish optimal LACI cut-offs for clinical use. Methods This retrospective cohort study enrolled HCM patients who underwent CMR between January 2015 and October 2023. LACI was calculated as the left atrial end-diastolic volume ratio to left ventricular end-diastolic volume. Cox regression and Kaplan-Meier survival analysis assessed associations between LACI and clinical outcomes, adjusting for potential confounding factors. The primary outcome was a composite endpoint of all-cause death and hospitalization for heart failure (HHF). Secondary outcomes included all-cause death, HHF, and new-onset AF. Receiver operating characteristic (ROC) analysis with Youden’s index was used to identify an optimal LACI cut-off for interested outcomes. Results Data from 183 participants, with a median age of 62 (IQR 51.5, 73.5) years old and 41% male, were analyzed. During a median follow-up of 4.2 years, 42 patients (22.9%) experienced the primary endpoint. Elevated LACI beyond the cut-offs independently predicted the primary composite endpoint (LACI ≥ 0.41: adjusted hazard ratio (aHR) 2.38, 95% confident interval (CI): 1.19, 4.78, p = 0.015) and HHF (LACI ≥ 0.44: aHR 4.79, 95% CI: 1.31, 17.54, p = 0.018) but not for all-cause death (LACI ≥ 0.37: aHR 1.03, 95% CI: 0.46, 2.28, p = 0.952) and new-onset AF (LACI ≥ 0.44: aHR 2.15, 95% CI: 0.89, 5.24, p = 0.090). Conclusion LACI is a robust prognostic marker for predicting a composite outcome of all-cause death and HHF in patients with HCM.Kaplan-Meier curves. ROC analysis.