Plasma Big Endothelin-1 Level and the Severity of New-onset Stable Coronary Artery Disease

Aim: To investigate the usefulness of the plasma big endothelin-1 (big ET-1) level in predicting the severity of new-onset stable angiography-proven coronary artery disease (CAD). Methods: A total of 963 consecutive stable CAD patients with more than 50% stenosis in at least one main vessel were enrolled. The patients were classified into the three groups according to the tertile of the Gensini score (GS, low GS < 20, n=300; intermediate GS 20-40, n=356 and high GS > 40, n=307), and the relationship between the big ET-1 level and GS was evaluated. Results: The plasma levels of big ET-1 increased significantly in association with increases in the GS tertile (p=0.007). A multivariate analysis suggested that the plasma big ET-1 level was an independent predictor for a high GS (OR=2.26, 95% CI: 1.23-4.15, p=0.009), and there was a positive correlation between the big ET-1 level and the GS (r=0.20, p=0.000). The area under the receiver operating characteristic curve (AUC) for the big ET-1 level in predicting a high GS was 0.64 (95% CI 0.60-0.68, p=0.000), and the optimal cutoff value for the plasma big ET-1 level for predicting a high GS was 0.34 fmol/mL, with a sensitivity of 62.6% and specificity of 60.3%. In the high-big ET-1 level group (>= 0.34 fmol/mL), there were significantly increased rates of three-vessel disease (43.6% vs. 35.4%, p=0.017) and a high GS [31 (17-54) vs. 24 (16-44), p=0.001] compared with that observed in the low-big ET-1 level group. Conclusions: The present findings indicate that the plasma big ET-1 level is a useful predictor of the severity of new-onset stable CAD associated with significant stenosis.