Sex‐Specific Prognostic Value of Left Atrioventricular Coupling Index in Acute Coronary Syndrome: Insights From Artificial Intelligence‐Enhanced 3‐Dimensional Echocardiography

Background Left atrioventricular coupling index (LACI) has emerged as a prognostic biomarker, but its sex‐specific relevance in acute coronary syndrome remains unclear. Methods This retrospective cohort included 880 patients with acute coronary syndrome (625 men; 255 women) undergoing percutaneous coronary intervention between February 2022 and June 2023. LACI was automatically quantified from 3‐dimensional echocardiography using an artificial intellgience‐based dynamic heart model. Patients were stratified by sex‐specific median LACI values and followed for major adverse cardiovascular events. Cox proportional hazards and Fine–Gray competing risk models evaluated associations between LACI and outcomes. A sensitivity analysis was performed in 3 ways: (1) using propensity score matching, (2) excluding patients with atrial fibrillation, and (3) repeating propensity score matching in the cohort after excluding patients with atrial fibrillation. Results were verified in 3 independent cohorts: 285 internal validation, 124 coronary computed tomography angiography, and 128 external 3‐dimensional echocardiography cohorts. Results Over a median 18‐month follow‐up, 219 major adverse cardiovascular events occurred. Women had significantly higher median LACI values than men. LACI was significantly associated with increased major adverse cardiovascular event risk in men (hazard ratio [HR], 1.23 [95% CI, 1.03–1.46]; P =0.020; P for interaction=0.027) but not in women. Restricted cubic spline analysis demonstrated a linear dose–response association in men. Fine–Gray analysis demonstrated a significant association between LACI and major adverse cardiovascular events in men. Findings remained consistent after AF exclusion, PSM, and across all validation cohorts. Conclusions Artificial intelligence‐derived LACI from 3‐dimensional echocardiography demonstrates clear sex‐specific prognostic value in acute coronary syndrome, and is significantly associated with adverse cardiovascular outcomes in men but not in women. These results support sex‐specific risk stratification and highlight the clinical relevance of atrioventricular coupling assessment. Registration URL: https://www.chictr.org.cn/ . Unique identifier: ChiCTR2500099592.