Abstract 3720: Early Treatment Initiation of Granulocyte-colony Stimulating Factor (G-CSF) after Late Revascularized Sub-acute Myocardial Infarction does not result in Better Improvement of Myocardial Function
G-CSF was demonstrated to improve myocardial function and perfusion after myocardial infarction in various animal studies. Recent data demonstrate, that the time point of treatment initiation may be crucial for the efficacy of G-CSF. We investigated the influence of G-CSF treatment initiation on myocardial function and stem cell mobilization in patients undergoing delayed percutaneous coronary intervention (PCI) for ST segment elevation myocardial infarction (STEMI).
Methods: Forty-four patients with late revascularized sub-acute STEMI were treated with either G-CSF or placebo over 5 days after successful PCI in a prospective, randomized, double-blinded, placebo-controlled phase 2 study. Of the G-CSF group (n=23, angina to PCI interval 32±45h), 13 patients received G-CSF early (started within 24h after PCI, mean 16±6, Group I). In 10 patients, G-CSF was initiated late (>24 hours after PCI, mean 49±26, Group II). Myocardial function and perfusion were assessed from baseline to 3 months after PCI using MRI. Mobilized stem cell populations were assessed by flow cytometry.
Results: Baseline ejection fraction was comparable in both groups (Group I: 42±15%, Group II: 40±10%, p=0.75). After 3 months, ejection fraction had increased by 4.5±11% in Group I, and by 8.1%±6% in Group II patients (p=0.39). None of the groups were superior to placebo treatment. No significant difference in myocardial perfusion could be observed in both groups. Group I patients demonstrated a slightly stronger mobilization of progenitor cells (CD34/CD133 57±31 cells/μL, CD34/CD31 56±31 cells/μL, CD34/c-kit 49±26 cell/μL) when compared to Group II patients (CD34/CD133 18±17 cells/μL, CD34/CD31 20±20 cells/μL, CD34/c-kit 16±5 cell/μL, p=0.06, p=0.08, p=0.09, respectively).
Conclusions: Although early administration of G-CSF is associated with a slightly increased capacity of stem cell mobilization, myocardial function of patients suffering from late revascularized STEMI does not benefit from G-CSF regardless the time point of treatment initiation.