2.2. Coronary angiogram

All patients underwent an emergent cardiac catheterization. An independent cardiologist blinded to the clinical data reviewed coronary angiography, and the assessment was compared with the primary assessment by the treating cardiologist. In case of any discrepancy between the assessments, a third investigator made the final interpretation. Obstructive coronary artery disease (CAD) was defined as stenosis ≧50% in the left main coronary artery and 70% in any other epicardial coronary arteries. Long LAD artery was defined as LAD artery supplying blood flow to more than one‐fourth of the inferior wall of the left ventricle in the right anterior oblique projection. Coronary blood flow was graded according to TIMI criteria (TIMI Study Group, ¹⁹⁸⁵). The site of the culprit lesion was determined by the angiographic appearance of thrombus or ulcerated plaque. Revascularization procedures including primary percutaneous coronary intervention (PCI) and CABG were performed at the discretion of the treating physician. A successful primary PCI was defined as a TIMI 3 flow after the procedure.