The purpose of this study is to evaluate left ventricular systolic ejection fraction and anterior or apical akinesis 1 month and 3 months after a myocardial infarction treated with primary PCI to determine whether improvement at 1 month differs from improvement at 3 months.

Inclusion Criteria:

• Older than 18 years old
• ST elevation myocardial infarction treated with primary PCI
• Anterior or apical akinesis and left ventricular ejection fraction ≤ 45% on early echocardiography (48hours - 7 days post myocardial infarction)
• Initial ECG showing at least 1 mm ST elevation in 2 leads corresponding to the same vascular territory

Exclusion Criteria:

• Known left ventricular systolic dysfunction before myocardial infarction
• Left bundle branch block
• Vital prognosis less than 6 months
• Cardiogenic shock
• Rescue PCI
• Sub-optimal echocardiographic imaging (contrast use is allowed)
• Significant valvular heart disease (moderate or severe)
• Surgical revascularization
• Pregnancy or breastfeeding
• Incapacity to provide informed consent

Patients presenting to teaching hospital or sent from community hopitals to teaching hospital for primary PCI