Abstract 3253: Mobilization of Stem Cells is a Predictor of LVEF Improvement After Intracoronary Infusion of Bone Marrow-derived Selected CD34+CXCR4+Cells in Patients With Acute MI
Acute MI induces mobilization of CD34+CXCR4+ cells which are enriched in early cardiac and endothelial markers. REGENT trial using intracoronary infusion of CXCR4+ cells showed no significant improvement of LVEF, however subgroup with baseline LVEF <37% had a significant increase of LVEF.
AIM: assessment of association between mobilization of stem cell and improvement of LVEF and reduction of the infarct size treated with intracoronary infusion of CD34+CXCR4+ cells.
PATIENTS AND METHODS: Inclusion criteria: anterior AMI, successful PCI, reduced LVEF <40%. Patients were randomized to receive intracoronary infusion of selected CD34+CXCR4+ cells (SEL, n=30) and control group without cell infusion (n=30). CD34+CXCR4+ cells were isolated from 100 –120ml of bone marrow using two-step immunomagnetic selection and infused using stop-flow technique. The median number of CD34+CXCR4+ cells was 1.90 × 106. Change of LV ejection fraction (LVEF), volumes, infarct size (LE) and adenosine perfusion test were measured by MRI before and 6 months after the procedure. Number of circulating CD34+CXCR4+ cells was measured before and 6 months after cells infusion.
RESULTS: Number of circulating CD34+CXCR4+ cells 24 hours after primary PCI was positively correlated with LVEF (r=0.51, p=0.004) and inversely with LE (r=−0.42, p=0.03) measured before cell infusion. Mobilization of cells was significantly higher in patients who had significant (Δ≥5%) absolute increase of LVEF 6 months after cell infusion [median, 6.2 (2.7–7.8) vs. 3.5 (1.3– 6.4) cells/μL, p<0.001). Number of cells was positively correlated with absolute increase of LVEF (r=0.49, p=0.003) and absolute reduction of LE (r=0.35, p=0.04) after 6 months. Number of circulating CD34+CXCR4+ cells was positively correlated with adenosine-induced stress test perfusion measured 6 months after cell infusion (r=0.43, p=0.03). In multivariate analysis number of circulating cells [OR 7.1 (2.4 –11.8)], baseline LVEF and time from the onset of symptoms to primary PCI were independent predictors of significant improvement of LVEF after 6 months in patients treated with BMC.
CONCLUSION: Mobilization of stem cells in acute MI is a predictor of LVEF improvement 6 months after intracoronary infusion of CD34+CXCR4+ cells.