One-day kinetics of myocardial engraftment after intracoronary injection of bone marrow mononuclear cells in patients with acute and chronic myocardial infarction

Objective: To investigate the kinetics of myocardial engraftment of bone marrow-derived mononuclear cells (BMNCs) after intracoronary injection using Tc-99m-d, l-hexamethylpropylene amine oxime (99mTc-HMPAO) nuclear imaging in patients with acute and chronic anterior myocardial infarction. Design: Nuclear imaging-derived tracking of BMNCs at 2 and 20 h after injection in the left anterior descending (LAD) coronary artery. Setting: Academical cardiocentre. Patients: Five patients with acute (mean (SD) age 58 (11) years; ejection fraction range 33-45%) and five patients with chronic (mean (SD) age 50 (6) years; ejection fraction range 28-34%) anterior myocardial infarction. Interventions: A total of 24.2 x 10(8)-57.0 x 10(8) BMNCs (20% labelled with 700-1000 MBq Tc-99m-HMPAO) were injected in the LAD coronary artery. Results: At 2 h after BMNC injection, myocardial activity was observed in all patients with acute (range 1.31-5.10%) and in all but one patient with chronic infarction (range 1.10-3.0%). At 20 h, myocardial engraftment was noted only in three patients with acute myocardial infarction, whereas no myocardial activity was noted in any patient with chronic infarction. Conclusions: Engraftment of BMNCs shows dynamic changes within the first 20 h after intracoronary injection. Persistent myocardial engraftment was noted only in a subset of patients with acute myocardial infarction.