Usefulness of Granulocyte Colony-Stimulating Factor in Patients With a Large Anterior Wall Acute Myocardial Infarction to Prevent Left Ventricular Remodeling (The Rigenera Study)

Intracoronary injection of bone marrow stem cells seems to improve left ventricular (LV) function after acute myocardial infarction (AMI). Granulocyte colony-stimulating factor (G-CSF) could improve myocardial function and perfusion noninvasively through mobilization of stem cells into peripheral blood, although previous clinical trials have produced controversial results. Forty-one patients with large anterior wall AMI at high risk of unfavorable remodeling were randomized 1:2 to G-CSF (10 μg/kg/day for 5 days) or to conventional therapy. All patients underwent successful primary or rescue percutaneous coronary intervention. LV function was assessed by echocardiography before G-CSF administration, ≥5 days after AMI, and at follow-up. Only patients with a LV ejection fraction <50% at baseline were enrolled in the study. After a median follow-up of 5 months (range 4 to 6) patients treated with G-CSF exhibited improvement in LV ejection fraction, from 40 ± 6% to 45 ± 6% (p = 0.068) in the absence of LV dilation (LV end-diastolic volume from 147 ± 33 to 144 ± 46 ml at follow-up, p = 0.77). In contrast, patients treated conventionally exhibited significant LV dilation (LV end-diastolic volume from 141 ± 35 to 168 ± 41 ml, p = 0.002) in the absence of change in LV ejection fraction (from 38 ± 6% to 38 ± 8%, p = 0.95). However, when comparing patients treated with G-CSF with controls, variations in these parameters were significantly different at 2-way analysis of variance (p = 0.04 for LV end-diastolic volume, p = 0.02 for LV ejection fraction). In conclusion, G-CSF prevents unfavorable LV remodeling and improves LV function in patients with large anterior wall AMI and decreased LV ejection fraction after successful percutaneous coronary intervention.