title: Myocardial washout rate of technetium-99m-sestamibi in the chronic phase predicts myocardial damage in patients with previous myocardial infarction.
abstract: OBJECTIVE
  This study aimed to clarify the correlation between the myocardial washout rate (WR) of technetium-99m hexakis 2-methoxy-isobutyl-isonitrile ((99m)Tc-sestamibi) and cardiac enzyme levels in patients with acute myocardial infarction (AMI) 6 months after the onset.
  
  
  METHODS
  Sixty-one consecutive AMI patients (mean age, 66.2 ± 9.7 years) who underwent percutaneous coronary intervention (PCI) on admission were enrolled. Creatinine kinase MB isoenzyme (CK-MB) levels were measured every 3 h. (99m)Tc-sestamibi myocardial scintigraphic images were obtained at the early (30 min) and delayed (4 h) phases after tracer injection for calculating heart-to-mediastinum (H/M) ratios and global WRs at 2 weeks (0 M) and 6 months (6 M) after the onset of AMI. Regional WRs in the culprit lesions (culprit WR) and the extent score (ES) and severity score (SS) of myocardial damage were also calculated.
  
  
  RESULTS
  PCI was performed 8.3 ± 7.7 h after AMI onset. At 6 M, the early H/M ratio (p = 0.04), delayed H/M ratio (p = 0.02), global WR (p = 0.01), culprit WR (p = 0.002), and delayed ES (p = 0.008) were alleviated. At 0 M, the peak CK-MB level correlated with the delayed H/M ratio (p = 0.003), global WR (p = 0.003), culprit WR (p < 0.001), early ES (p = 0.03), delayed ES (p = 0.01), early SS (p = 0.001), and delayed SS (p < 0.001). At 6 M, the peak CK-MB level correlated with the delayed H/M ratio (p < 0.001), global WR (p = 0.005), culprit WR (p = 0.001), early ES (p = 0.001), delayed ES (p < 0.001), early SS (p < 0.001), and delayed SS (p < 0.001).
  
  
  CONCLUSIONS
  These results demonstrated that (99m)Tc-sestamibi WR in the chronic phase as well as that in the acute phase reflects the extent of initial myocardial damage in AMI patients after PCI. Moreover, it might indicate the myocardial condition in the clinical course.
authors.affiliation: Division of Cardiology, Department of Internal Medicine, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae-ku, Kawasaki, Kanagawa 216-8511, Japan. k2ashikaga@marianna-u.ac.jp
authors.forename: Kohei
authors.initials: K
authors.lastname: Ashikaga
authors.forename: Yoshihiro J
authors.initials: YJ
authors.lastname: Akashi
authors.forename: Kihei
authors.initials: K
authors.lastname: Yoneyama
authors.forename: Keisuke
authors.initials: K
authors.lastname: Kida
authors.forename: Kengo
authors.initials: K
authors.lastname: Suzuki
authors.forename: Fumihiko
authors.initials: F
authors.lastname: Miyake
mesh_terms: D000208:Acute Disease; D000368:Aged; D017130:Angioplasty; D002908:Chronic Disease; D003402:Creatine Kinase / Q000378:metabolism; D005260:Female; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology* / Q000628:therapy; D009206:Myocardium / Q000201:enzymology / Q000378:metabolism* / Q000473:pathology*; D020097:Natriuretic Peptide, Brain / Q000378:metabolism; D011877:Radionuclide Imaging; D017256:Technetium Tc 99m Sestamibi / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007527:Isoenzymes; D020097:Natriuretic Peptide, Brain; D017256:Technetium Tc 99m Sestamibi; D003402:Creatine Kinase