title: Significance of performing 123I-metaiodobenzylguanidine myocardial scintigraphy at different times for the long-term prediction of cardiac events in patients with dilated cardiomyopathy.
abstract: OBJECTIVE
  Although it has been reported that (123)I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy is useful for assessing the prognosis of dilated cardiomyopathy (DCM), there have been no reports regarding how interval MIBG imaging should be performed during follow-up. We investigated the significance of performing MIBG at different times for the long-term prediction of cardiac events in DCM patients.
  
  
  METHODS
  The participants were 36 DCM patients who did not sustain cardiac events for 2 years after beta-blocker induction. MIBG was performed 6 months and 2 years after beta-blocker induction and the images analyzed to obtain the extent score, severity score (SEV), and the washout rate. Echocardiography was performed at the same time.
  
  
  RESULTS
  Eight patients experienced a cardiac event during follow-up (cardiac death: two patients; heart failure requiring hospitalization: six patients). Although no significant difference was found in any MIBG parameters or left ventricular ejection fraction between patients who experienced a cardiac event and those who did not after 6 months, early extent score, early SEV, delayed SEV, and washout rate were found to be significantly higher for patients who experienced a cardiac event after 2 years. In multivariate analysis using Cox proportional hazard model, none of the MIBG parameters or left ventricular ejection fraction after 6 months was identified as a predictor of cardiac events. However, delayed SEV after 2 years (hazard ratio 1.067, P = 0.0435) was a significant predictor of cardiac events.
  
  
  CONCLUSIONS
  The study suggested that performing MIBG at least once every 2 years allows long-term prediction of cardiac events in the follow-up of DCM patients.
authors.affiliation: Department of Cardiovascular Medicine, Toho University Omori Medical Center, 6-11-1 Omori-nishi, Ohta-ku, Tokyo 143-8541, Japan.
authors.forename: Rine
authors.initials: R
authors.lastname: Nakanishi
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Yuko
authors.initials: Y
authors.lastname: Utanohara
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takamura
authors.forename: Aritomo
authors.initials: A
authors.lastname: Inoue
authors.forename: Shohei
authors.initials: S
authors.lastname: Yamashina
authors.forename: Atsushi
authors.initials: A
authors.lastname: Namiki
authors.forename: Junichi
authors.initials: J
authors.lastname: Yamazaki
mesh_terms: D019797:3-Iodobenzylguanidine; D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000704:Analysis of Variance; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D055414:Myocardial Perfusion Imaging; D011379:Prognosis; D013997:Time Factors
chemical_list: D000319:Adrenergic beta-Antagonists; D019797:3-Iodobenzylguanidine