Abstract 2670: Time to Granulocyte-Colony Stimulating Factor Treatment after Acute Myocardial Infarction Does Not Affect Left Ventricular Recovery: Results from the STEMMI Trial
Introduction: Granulocyte-colony stimulating factor (G-CSF) therapy after a STEMI does not affect left ventricular systolic function when compared to placebo. However, recent human and animal studies suggest that the timing of G-CSF therapy is crucial.
Hypothesis: G-CSF improves recovery of left ventricular ejection fraction if administered very early after a STEMI.
Methods: The STEMMI trial MRI-subpopulation was analyzed. The trial included 58 patients (47 men; 56 [SD 9] years) with STEMI treated with primary PCI <12 hours after symptom onset. Patients were randomized to double blind treatment with G-CSF (10 μg/kg/day) or placebo for 6 days. Treatment with G-CSF (time to G-CSF) was initiated 30 hours (range 17 – 65) after PCI. Left ventricular function was evaluated with cardiac MRI and analyzed by an independent blinded core laboratory.
Results: Circulating CD34+ cells increased during G-CSF therapy. However, there was no correlation between time to G-CSF and maximum plasma concentration of CD34+ cells (r=-0.3, p=0.2). Baseline ejection fraction was independent of time to G-CSF. The recovery of ejection fraction from baseline to 6 months was not associated with time to G-CSF (regression coefficient 0.2/hour, 95% CI -0.2 to 0.5), an identical improvement was found in the placebo group (p=0.8). There was no association between plasma concentrations of CD34+ cells and improvement in left ventricular function.
Conclusions: We found no indication that early initiation of treatment with G-CSF improves recovery of left ventricular ejection fraction as compared to both late G-CSF and placebo. It remains to be determined if treatment initiation <17 hours after PCI improves recovery.