title: Relationship between late ventricular potentials and myocardial 123I-metaiodobenzylguanidine scintigraphy in patients with dilated cardiomyopathy with mild to moderate heart failure: results of a prospective study of sudden death events.
abstract: OBJECTIVE
  Late ventricular potentials (LPs) are considered to be useful for identifying patients with heart failure at risk of developing ventricular arrhythmias. (123)I-metaiodobenzylguanidine (MIBG) scintigraphy, which is used to evaluate cardiac sympathetic activity, has demonstrated cardiac sympathetic denervation in patients with malignant ventricular tachyarrhythmias. This study was undertaken to clarify the relationship between LPs and (123)I-MIBG scintigraphy findings in patients with dilated cardiomyopathy (DCM).
  
  
  METHODS
  A total of 56 patients with DCM were divided into an LP-positive group (n = 24) and an LP-negative group (n = 32). During the compensated period, the delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS), and washout rate (WR) were determined from (123)I-MIBG images and plasma brain natriuretic peptide (BNP) concentrations were measured. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular ejection fraction (LVEF) were simultaneously determined by echocardiography.
  
  
  RESULTS
  LVEDV, LVESV, LVEF and plasma BNP concentrations were similar in the two groups. However, TDS was significantly higher (35 ± 8 vs. 28 ± 6, p < 0.005), the H/M ratio was significantly lower (1.57 ± 0.23 vs. 1.78 ± 0.20, p < 0.005), and the WR was significantly higher (60 ± 14% vs. 46 ± 12%, p < 0.001) in the LP-positive than in the LP-negative group. The average follow-up time was 4.5 years, and there were nine sudden deaths among the 56 patients (16.1%). In logistic regression analysis, the incidences of sudden death events were similar in those LP-negative with WR <50%, LP-negative with WR ≥ 50% and LP-positive with WR <50% (0%, 10.0% and 14.3%, respectively), but was significantly higher (41.2%) in those LP-positive with WR ≥ 50% (p < 0.01, p < 0.05, and p < 0.05, respectively).
  
  
  CONCLUSIONS
  The present study demonstrated that the values of cardiac (123)I-MIBG scintigraphic parameters were worse in LP-positive DCM patients than in LP-negative DCM patients. Furthermore, in LP-positive DCM patients with a high WR, the incidence of sudden death events was higher than that in other subgroups of DCM patients.
authors.affiliation: Department of Medicine and Biological Science, Cardiovascular Medicine, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma 371-0034, Japan. s-kasama@bay.wind.ne.jp
authors.forename: Shu
authors.initials: S
authors.lastname: Kasama
authors.forename: Takuji
authors.initials: T
authors.lastname: Toyama
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Kaneko
authors.forename: Toshiya
authors.initials: T
authors.lastname: Iwasaki
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sumino
authors.forename: Hisao
authors.initials: H
authors.lastname: Kumakura
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Minami
authors.forename: Shuichi
authors.initials: S
authors.lastname: Ichikawa
authors.forename: Naoya
authors.initials: N
authors.lastname: Matsumoto
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sato
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kurabayashi
mesh_terms: D019797:3-Iodobenzylguanidine; D000200:Action Potentials; D001145:Arrhythmias, Cardiac / Q000150:complications; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000000981:diagnostic imaging* / Q000473:pathology*; D003645:Death, Sudden; D005260:Female; D006333:Heart Failure / Q000150:complications* / Q000473:pathology; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011877:Radionuclide Imaging; D012306:Risk
chemical_list: D019797:3-Iodobenzylguanidine