title: Intracoronary stem-cell injection after myocardial infarction: microcirculation sub-study.
abstract: BACKGROUND
  The injection of stem cells in the context of acute myocardial infarction (AMI) has been tested almost exclusively by anterograde intra-arterial coronary (IAC) delivery. The retrograde intravenous coronary (IVC) delivery may be an additional route.
  
  
  OBJECTIVE
  To compare the cell distribution and retention pattern in the anterograde and retrograde routes. To investigate the role of microvascular obstruction by magnetic resonance imaging in cell retention by cardiac tissue after the injection of bone marrow mononuclear cells (BMMC) in AMI.
  
  
  METHODS
  This was a prospective, open label, randomized study. Patients with AMI who presented: (1) successful chemical or mechanical reperfusion within 24 hours of symptom onset and (2) infarction involving more than 10% of the left ventricle (LV) at the myocardial scintigraphy were included in the study. One hundred million BMMC were injected into the infarction-related artery through IAC route, or vein through the IVC route. One percent of the injected cells were labeled with 99mTc-hexamethyl-propylene-amine-oxime (99mTc-HMPAO). Cell distribution was evaluated at 4 and 24 hours after the myocardial scintigraphy injection. Cardiac magnetic resonance imaging was performed before cell injection.
  
  
  RESULTS
  Thirty patients were randomized into three groups. There were no serious adverse events related to the procedure. The early and late retention of labeled cells was higher in the IAC group than in IVC group, regardless of the presence of microcirculation obstruction.
  
  
  CONCLUSIONS
  The injection using the retrograde approach was feasible and safe. Cell retention by cardiac tissue was higher using the anterograde approach. More studies are needed to confirm these findings.
authors.affiliation: Hospital Pro-Cardíaco, Botafogo, Brazil. rodrigocm@cardiol.br
authors.forename: Rodrigo de Carvalho
authors.initials: Rde C
authors.lastname: Moreira
authors.forename: Andréa Ferreira
authors.initials: AF
authors.lastname: Haddad
authors.forename: Suzana Alves
authors.initials: SA
authors.lastname: Silva
authors.forename: André Luiz Silveira
authors.initials: AL
authors.lastname: Souza
authors.forename: Fábio Antônio Abrantes
authors.initials: FA
authors.lastname: Tuche
authors.forename: Mônica Amorim de
authors.initials: MA
authors.lastname: Oliveira
authors.forename: Cláudio Tinoco
authors.initials: CT
authors.lastname: Mesquita
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Rochitte
authors.forename: Radovan
authors.initials: R
authors.lastname: Borojevic
authors.forename: Hans Fernando Rocha
authors.initials: HF
authors.lastname: Dohmann
mesh_terms: D016026:Bone Marrow Transplantation / Q000009:adverse effects / Q000379:methods*; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007269:Injections, Intra-Arterial / Q000379:methods; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D018709:Statistics, Nonparametric; D033581:Stem Cell Transplantation / Q000009:adverse effects / Q000379:methods*; D019690:Technetium Tc 99m Exametazime
chemical_list: D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime