The invention provides various methods of identifying myocardial infarction (MI) patients who have microvascular obstruction (MO), persistent microvascular obstruction (PMO), reperfusion hemorrhage, iron deposition, chronic iron deposition, and/or fat infiltration/accumulation. The invention provides various methods of identifying myocardial infarction (MI) patients who are at risk of prolonged inflammation burden in heart, adverse cardiac remodeling, electrical abnormality, mechanical abnormality, malignant cardiac arrhythmia, ischemic heart failure, and/or sudden cardiac death. The invention also provides various methods of treating these MI patients with chelation drugs, anti-inflammatory drugs, fat-lowering drugs, cooling therapies, or device therapies, or their combinations.