Clinical studies found that poor ST-segment resolution (STR) in electrocardiogram (ECG) occurred in major adverse cardiovascular events (MACE), arrhythmia and heart failure was significantly higher . In clinical work, in patients have poor ST-segment decline, the investigators found by CMR-LGE the corresponding myocardium become thinner and other signs of myocardial scar.

The investigators aimed to establish whether poor ST-segment resolution in ECG, as well as CMR-LGE, could detect the presence of myocardial scar in early STEMI patients. In order to provide convenient, cheap and widely used test method for patients who cannot tolerate CMR-LGE.

42 STEMI patients with single-branch coronary artery stenosis or occlusion were enrolled. ST-segment elevations were measured on the baseline and 24 hours after PCI. The study population was divided into two groups by late gadolinium enhanced cardiac magnetic resonance (LGE- CMR), with transmural myocardial scar (>75%) or non-transmural myocardial scar (<75%).

Inclusion Criteria:

1. Single-branch coronary artery stenosis or occlusion
2. Restoration of coronary perfusion to TIMI flow grade 3 after PCI

Exclusion Criteria:

1. A prior history of the acute coronary syndrome
2. Coronary revascularization
3. Severe chronic kidney disease
4. Intracardiac pacing leads or other implants precluding CMR-LGE
5. Hemodynamic instability
6. Known claustrophobia

42 patients.