EDN1 and diabetes mellitus: When adding big ET-1 (as a continuous variable), a diagnosis of diabetes, and the interaction term of big ET-1 × diagnosis of diabetes (big ET-1 × diabetes) into a Cox regression, after adjusting for traditional and angiographic risk factors, we found that the interaction term was statistically significant for predicting both MACEs and the secondary end points (p for interaction < 0.0001).