Granulocyte-colony stimulating factor for large anterior ST-elevation myocardial infarction: rationale and design of the prospective randomized phase III STEM-AMI OUTCOME trial.

BACKGROUND: Granulocyte-colony stimulating factor (G-CSF) has been clinically tested in ST-elevation myocardial infarction (STEMI) with mixed results. Our 3-year follow-up data from STEM-AMI trial documented a sustained benefit of G-CSF on adverse ventricular remodeling after large anterior STEMI, when administered early and at a high-dose in patients with left ventricular (LV) dysfunction. The Aim of the present trial is to establish whether G-CSF improves hard clinical long-term outcomes.

METHODS: The STEM-AMI OUTCOME is a prospective, multicenter, randomized, open-label, phase III trial. It will include 1,530 patients with anterior STEMI undergoing primary percutaneous coronary intervention 2 to 24 hours after symptoms onset and with LV ejection fraction ≤45% after successful reperfusion. Patients will be randomized 1:1 to G-CSF and/or standard treatment. The primary end point is a reduced occurrence of all-cause death, recurrence of myocardial infarction, or hospitalization due to heart failure in G-CSF-treated patients. Left ventricular remodeling will be assessed via cardiac ultrasound and a substudy with cardiac magnetic resonance will be carried out in 120 subjects. Accrual and follow-up periods will last 3 and 2 years, respectively.

CONCLUSIONS: The STEM-AMI OUTCOME study is designed to be a rigorous controlled phase III trial with adequate statistical power to conclusively assess efficacy of G-CSF treatment in STEMI.