Abstract 11330: Predictors of Response to Intracoronary Delivery of CD34+CXCR4+ Enriched Bone Marrow Derived Stem Cells (AMR-001) Early After STEMI
Background. High dose CD34+/CXCR4+ stem cells improve myocardial perfusion when administered via the infarct related artery early after STEMI by homing to hypoxic tissue in response to stromal derived factor (SDF-1) release. We investigated predictors of physiologic response.
Methods: 14 of 16 STEMI patients with LVEF < 50% were treated with AMR-001 6-10 days post stent placement. Clinical evaluation after 6 months included echo for contractile reserve (Stress-Rest LVEF), SPECT sestamibi scan and cardiac MRI. Changes in myocardial perfusion were measured by resting total severity score (RTSS, Emory Cardiac Toolbox) and by percent left ventricular infarct (%LVInf) via SPECT and MRI. AMR-001 release testing included cell counts (CD34+, CXCR4+), purity and mobility (migration to SDF-1 reflecting ischemia).
Results: Responders tended to receive more mobile cells and have bigger infarcts with less contractile reserve (Tables). Improvement in RTSS correlated significantly with: number of mobile cells (r=0.75, p=0.002), lack of contractile reserve (r=-0.55, p=0.04) and %LVInf by SPECT (r=0.63, p=0.02) and CMR (r=0.74, p=0.003). Improvement in %LVInf (CMR) correlated significantly with number of mobile cells administered (r=0.67, p=0.02) [all Spearman’s]. Neither total CD34+ nor total CXCR4+ cells correlated with changes in LV physiology. Analyses were similar when patients were grouped by median values.
Conclusions: These data support the importance of CD34+ cell mobility and the biologic relevance of CXCR4+ as SDF-1 ligand for preserving myocardium early after STEMI. Larger trials will investigate the clinical importance of these physiologic observations.
- © 2012 by American Heart Association, Inc.