Diagnostic value of ST-segment elevation in lead aVR exceeding V1 for identifying significant left main coronary artery disease in acute coronary syndrome

BACKGROUND: Left main coronary artery (LMCA) disease carries high morbidity and mortality and requires early identification. Although ST-segment elevation in lead aVR has been associated with severe coronary artery disease, its diagnostic value relative to lead V1 remains unclear. METHODS: This cross-sectional study included 180 patients with acute coronary syndrome undergoing coronary angiography. Patients were stratified according to ST-segment elevation in lead aVR greater than V1 versus ≤ V1. Significant LMCA stenosis was defined as ≥50% luminal narrowing. Diagnostic performance was evaluated using validity measures, receiver operating characteristic (ROC) analysis, and multivariable logistic regression. CONCLUSIONS: ST-segment elevation in lead aVR exceeding that in lead V1 was independently associated with LMCA disease in patients with acute coronary syndrome and provided effective diagnostic stratification in this cohort. This simple ECG finding may assist early risk stratification and prompt consideration of urgent invasive evaluation, although external validation in larger prospective studies is warranted.