title: Magnetic resonance imaging (MRI) of inflamed myocardium using iron oxide nanoparticles in patients with acute myocardial infarction - preliminary results.
abstract: OBJECTIVE
  Superparamagnetic iron oxide nanoparticle (SPIO)-based molecular imaging agents targeting macrophages have been developed and successfully applied in animal models of myocardial infarction. The purpose of this clinical trial was to investigate whether magnetic resonance imaging (MRI) of macrophages using ferucarbotran (Resovist®) allows improved visualisation of the myocardial (peri-)infarct zone compared to conventional gadolinium-based necrosis/fibrosis imaging in patients with acute myocardial infarction.
  
  
  METHODS
  The clinical study NIMINI-1 was performed as a prospective, non-randomised, non-blinded, single agent phase III clinical trial (NCT0088644). Twenty patients who had experienced either an acute ST-elevation or non-ST-elevation myocardial infarction (STEMI/NSTEMI) were included to this study. Following coronary angiography, a first baseline cardiovascular magnetic resonance (CMR) study (pre-SPIO) was performed within seven days after onset of cardiac symptoms. A second CMR study (post-SPIO) was performed either 10 min, 4h, 24h or 48h after ferucarbotran administration. The CMR studies comprised cine-CMR, T2-weighted "edema" imaging, T2-weighted cardiac imaging and T1-weighted late-gadolinium-enhancement (LGE) imaging.
  
  
  RESULTS
  The median extent of short-axis in-plane LGE was 28% (IQR 19-31%). Following Resovist® administration the median extent of short-axis in-plane T2-weighted hypoenhancement (suggestive of intramyocardial haemorrhage and/or SPIO accumulation) was 0% (IQR 0-9%; p=0.68 compared to pre-SPIO). A significant in-slice increase (>3%) in the extent of T2-weighted "hypoenhancement" (post-SPIO compared to pre-SPIO) was seen in 6/16 patients (38%). However, no patient demonstrated "hypoenhancement" in T2-weighted images following Resovist® administration that exceeded the area of LGE.
  
  
  CONCLUSIONS
  T2/T2-weighted MRI aiming at non-invasive myocardial macrophage imaging using the approved dose of ferucarbotran does not allow improved visualisation of the myocardial (peri-) infarct zone compared to conventional gadolinium-based necrosis/fibrosis imaging.
authors.affiliation: Division of Cardiology, Robert-Bosch-Krankenhaus, Stuttgart, Germany. ali.yilmaz@rbk.de
authors.forename: Ali
authors.initials: A
authors.lastname: Yilmaz
authors.forename: Sabine
authors.initials: S
authors.lastname: Rösch
authors.forename: Karin
authors.initials: K
authors.lastname: Klingel
authors.forename: Reinhard
authors.initials: R
authors.lastname: Kandolf
authors.forename: Xavier
authors.initials: X
authors.lastname: Helluy
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Hiller
authors.forename: Peter M
authors.initials: PM
authors.lastname: Jakob
authors.forename: Udo
authors.initials: U
authors.lastname: Sechtem
mesh_terms: D005260:Female; D005290:Ferric Compounds; D006801:Humans; D008264:Macrophages; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis*; D009206:Myocardium / Q000473:pathology*; D053758:Nanoparticles; D011446:Prospective Studies
chemical_list: D005290:Ferric Compounds; C000499:ferric oxide