Abstract 556: Early, Simple, Noninvasive Predictors of Left Main or 3-Vessel Disease in Patients with Non-ST-Segment Elevation Acute Coronary Syndrome
In patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS), identification of left main or 3-vessel disease (LM/3VD) is crucial for deciding whether to initiate early treatment with clopidgrel, which may increase the risk of surgical bleeding. To identify an early, simple predictor of LM/3VD, we evaluated clinical variables on admission in 501 patients with NSTE-ACS. Patients with bundle branch block, left ventricular hypertrophy, and paced rhythm were excluded. ST-segment shifts and the widest QRS duration were measured on admission 12-lead ECG. Troponin T (TnT), brain natriuretic peptide (BNP), and high-sensitivity C-reactive protein (hsCRP) were also measured on admission. All patients underwent coronary angiography a mean of 3 days after admission. Ninety-six patients had LM/3VD. Patients with LM/3VD were older (68±11 vs 66±11 years, p=0.03) and had higher incidences of diabetes mellitus (49 vs 31 %, p<0.01), Killip class ≥2 (21 vs 5 %, p<0.01) and positive TnT (54 vs 29 %, p<0.01) than did those without LM/3VD. Patients with LM/3VD also had greater ST-segment depression in all leads except aVR (8±6 vs 3±4 mm, p<0.01), greater ST-segment elevation in lead aVR (0.7±0.6 vs 0.1±0.3 mm, p<0.01), a longer QRS duration (102±10 vs 84±8 ms, p<0.01), and higher levels of BNP (284±312 vs 162±281 pg/ml, p<0.01) and hsCRP (0.488±0.906 vs 0.351±0.612 mg/dl, p=0.09). The frequency of death, (re)infarction, or urgent revascularization 30 days after admission were 48% and 10% with and without LM/3VD, respectively (p<0.01). On multivariable analysis, QRS duration (OR 9.04, p<0.01), the degree of ST-segment elevation in lead aVR (OR 7.10, p<0.01), and positive TnT (OR 1.52, p<0.05) were independent predictors of LM/3VD. QRS duration >90 ms and ST-segment elevation in lead aVR ≥0.5 mm best identified LM/3VD. QRS duration >90 ms, ST-segment elevation in lead aVR ≥0.5 mm, and positive TnT identified LM/3VD with sensitivities of 88%, 76%, and 54% (p<0.01), and specificities of 88%, 86%, and 71% (p<0.01), respectively. In patients with NSTE-ACS, prolonged QRS duration, ST-segment elevation in lead aVR, and positive TnT on admission are useful predictors of LM/3VD. QRS duration >90 ms is the most sensitive predictor of LM/3VD.