The purpose of this trial is to investigate the effect of treatment with granulocyte-colony stimulating factor (G-CSF) bone marrow stimulation on circulating stem cells' ability to develop new blood vessels in the myocardium after an acute myocardial infarction.

Intracoronary infusion of bone-marrow stem cells after a ST elevation myocardial infarction (STEMI) seems to improve cardiac function. An alternative strategy is increase of circulating stem cells by mobilisation from the bone marrow with Granulocyte-Colony Stimulating Factor (G-CSF).

Objective: To determine the short-term (30 days) safety of G-CSF therapy after a STEMI treated with acute percutaneous coronary intervention (PCI).

Methods: Patients with STEMI treated with PCI <12 hours after symptom onset were randomised (1:1) to G-CSF (10 μg/kg/d) or placebo for 6 days in a double-blind design. Other inclusion criteria: age 20-70 years, culprit lesion in a large coronary artery, and peak CKMB >100 microgram/L. Follow-up was done after 1, 5 and 6 months, with an angiogram at 5 months.

Inclusion Criteria:

• Patients between 20 and 70 years with STEMI were eligible if they had a successful PCI within 12 hours after onset of symptoms.
• The target lesion had to be located in the proximal section of the left anterior descending (LAD), left circumflex (LCX) or right coronary artery (RCA).
• Only patients with creatine kinase [CK]-MB >100 microgram/L or development of Q waves in the electrocardiogram were included.

Exclusion Criteria:

• Ventricular arrhythmia after PCI requiring treatment
• Pregnancy
• Unprotected left main stem lesion
• History of prior myocardial infarction
• Diagnosed or suspected cancer
• New York Heart Association (NYHA) class 3-4
• Known severe claustrophobia
• Significant stenosis in another coronary vessel than the acutely treated vessel, that might demand treatment with PCI or coronary artery bypass graft surgery (CABG) prior to the last follow-up exam.