Coronary Angiography
Coronary angiography (CAG) was performed within 90 minutes of hospital admission. All patients received dual antiplatelet therapy with aspirin (300 mg) and clopidogrel (600 mg) or ticagrelor (180 mg) loading dose before CAG. Preprocedural anticoagulation consisted of intravenous unfractionated heparin (70 IU/kg) in all cases. Coronary angiograms were recorded to digital media for quantitative analysis (DICOM viewer, MedCom GmbH, Darmstadt, Germany). Digital angiograms were evaluated by 2 experienced cardiologists who were blinded to other patient information. In case of any conflicts regarding the assessments, an agreement was reached by consensus. The degree of coronary flow before PCI was classified by thrombolysis in myocardial infarction (TIMI) grade flow as assessed by the investigators. Patients with TIMI grade 2 or 3 flow in the IRA were considered to have a patent vessel. Primary PCI with stent implantation was performed according to current guidelines. The purpose of the p-PCI procedure was to obtain residual stenosis of <20% in IRA by visual evaluation. An optimal angiographic result was defined as the presence of TIMI grade 3 flow in the IRA following p-PCI. An unsuccessful procedure was defined as a procedure resulting in TIMI grade 0-1. Use of glycoprotein IIb/IIIa inhibitors (i.e. tirofiban) was left to the discretion of the attending physician. Complete ST-segment resolution was defined as a reduction of >70% in the summed 12-lead extent of ST-segment elevation from baseline to the post-procedural electrocardiogram, which was recorded at 90th minute after the first balloon inflation.