Myocardial blood flow and infarct size after CD133+ cell injection in large myocardial infarction with good recanalization and poor reperfusion: Results from a randomized controlled trial

OBJECTIVE: Large acute ST-elevation myocardial infarction (STEMI) sometimes leaves extensive ischemic damage despite timely and successful primary angioplasty. This clinical picture of good recanalization with incomplete reperfusion represents a good model to assess the reparative potential of locally administered cell therapy. Thus, we conducted a randomized controlled trial aimed at evaluating the effect of intracoronary administration of CD133 stem cells on myocardial blood flow and function in this setting. METHODS: Fifteen patients with large anterior STEMI, myocardial blush grade 0-1 and more than 50% ST-elevation recovery after optimal coronary recanalization (TIMI 3 flow) with stenting were randomly assigned to receive CD133 cells from either bone marrow (group A) or peripheral blood (group B), or to stay on drug therapy alone (group C). The cells were intracoronary injected within 10-14 days of STEMI. Infarct-related myocardial blood flow (MBF) was evaluated by NH positron emission tomography 2-5 days before cell administration and after 1 year. RESULTS: MBF increased in the infarct area from 0.419 (0.390-0.623) to 0.544 (0.371-0.729) ml/min per g in group A, decreased from 0.547 (0.505-0.683) to 0.295 (0.237-0.472) ml/min per g in group B and only slightly changed from 0.554 (0.413-0.662) to 0.491 (0.453-0.717) ml/min per g in group C (A vs. C: P = 0.023; B vs. C: P = 0.066). Left ventricular volume tended to increase more in groups B and C than in group A, ejection fraction and wall motion score index remained stable in the three groups. CONCLUSION: These findings support the hypothesis that intracoronary administration of bone marrow-derived, but not peripheral blood-derived CD133 cells 10-14 days after STEMI may improve long-term perfusion.