title: Microvascular obstruction on delayed enhancement cardiac magnetic resonance imaging after acute myocardial infarction, compared with myocardial (201)Tl and (123)I-BMIPP dual SPECT findings.
abstract: BACKGROUND
  The hypo-enhanced regions within the hyper-enhanced infarct areas detected by cardiac magnetic resonance (CMR) imaging reflect microvascular obstruction (MO) after acute myocardial infarction (AMI). The combined myocardial thallium-201 ((201)Tl)/iodine-123-15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid ((123)I-BMIPP) dual single-photon emission computed tomography (SPECT) is a useful tool for detecting myocardial reversibility after AMI. We evaluated whether MO could be an early predictor of irreversible myocardial damage in comparison with (201)Tl and (123)I-BMIPP dual SPECT findings in AMI patients.
  
  
  METHODS
  Sixty-two patients with initial AMI who successfully underwent coronary revascularization were enrolled. MO was defined by CMR imaging. Patients were divided into 2 groups as follows: MO group (n=32) and non-MO group (n=30). Scintigraphic defect scores were calculated using a 17-segment model with a 5-point scoring system. The mismatch score (MMS) was calculated as follows: the total sum of (Σ) (123)I-BMIPP defect score minus Σ(201)Tl defect score. The percentage mismatch score (%MMS) was calculated as follows: MMS/(Σ(123)I-BMIPP score)×100 (%).
  
  
  RESULTS
  The percentage infarct size (%IS) was significantly greater in the MO group than in the non-MO group (32.2±13.8% vs. 18.3±12.1%, p<0.001). The %MMS significantly correlated with the %IS and the percentage MO (r=-0.26, p=0.03; r=-0.45, p<0.001, respectively). The %MMS was significantly greater in the non-MO group than in the MO group (45.4±42.4% vs. 13.3±28.0%, p=0.001), and was an independent predictor for MO (OR 0.97, 95%CI 0.94-0.99, p=0.02).
  
  
  CONCLUSIONS
  Our results reconfirm that, in comparison with myocardial dual scintigraphy, MO is an important structural abnormality. CMR imaging is useful for the early detection of irreversible myocardial damage after AMI.
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan; Department of Cardiology, Kainan Hospital, Yatomi, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mori
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan. Electronic address: sisobe@med.nagoya-u.ac.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Isobe
authors.affiliation: Department of Cardiology, Kainan Hospital, Yatomi, Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Sakai
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Yamada
authors.affiliation: Department of Cardiology, Kainan Hospital, Yatomi, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Department of Cardiology, Kainan Hospital, Yatomi, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Miura
authors.affiliation: Department of Cardiology, Yokkaichi Municipal Hospital, Yokkaichi, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Uchida
authors.affiliation: Department of Cardiology, Yokkaichi Municipal Hospital, Yokkaichi, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Kanashiro
authors.affiliation: Department of Cardiology, Yokkaichi Municipal Hospital, Yokkaichi, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ichimiya
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okumura
authors.affiliation: Department of Cardiology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media; D005227:Fatty Acids; D005260:Female; D006801:Humans; D007089:Image Enhancement; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D055806:Microvessels / Q000000981:diagnostic imaging / Q000473:pathology; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000175:diagnosis; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014652:Vascular Diseases / Q000150:complications / Q000175:diagnosis*
chemical_list: D003287:Contrast Media; D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; C049338:iodofiltic acid
keywords: (201)Tl and (123)I-BMIPP dual SPECT; Acute myocardial infarction; Magnetic resonance imaging; Microvascular obstruction