An Early and Simple Predictor of Severe Left Main and/or Three-Vessel Disease in Patients With Non–ST-Segment Elevation Acute Coronary Syndrome

Clopidogrel should be initiated as soon as possible in patients with non–ST-segment elevation acute coronary syndrome (NSTE-ACS) except those who urgently require coronary artery bypass grafting (CABG). The present study assessed the ability to predict severe left main coronary artery and/or 3-vessel disease (LM/3VD) that would most likely require urgent CABG based on only clinical factors on admission in 572 patients with NSTE-ACS undergoing coronary angiography. Severe LM/3VD was defined as ≥75% stenosis of LM and/or 3VD with ≥90% stenosis in ≥2 proximal lesions of the left anterior descending coronary artery and other major epicardial arteries. Patients were divided into the 3 groups according to angiographic findings: no LM/3VD (n = 460), LM/3VD but not severe LM/3VD (n = 57), and severe LM/3VD (n = 55). Severe LM/3VD was associated with a higher rate of urgent CABG compared to no LM/3VD and LM/3VD but not severe LM/3VD (46%, 2%, and 2%, p <0.001). On multivariate analysis, degree of ST-segment elevation in lead aVR was the strongest predictor of severe LM/3VD (odds ratio 29.1, p <0.001), followed by positive troponin T level (odds ratio 1.27, p = 0.044). ST-segment elevation ≥1.0 mm in lead aVR best identified severe LM/3VD with 80% sensitivity, 93% specificity, 56% positive predictive value, and 98% negative predictive value. In conclusion, ST-segment elevation ≥1.0 mm in lead aVR on admission electrocardiogram is highly suggestive of severe LM/3VD in patients with NSTE-ACS. Selected patients with this finding might benefit from promptly undergoing angiography, withholding clopidogrel to allow early CABG.