title: Risk stratification of patients with prior myocardial infarction and advanced left ventricular dysfunction by gated myocardial perfusion SPECT imaging.
abstract: BACKGROUND
  The Multicenter Automatic Defibrillator Implantation Trial II (MADIT-II) has shown that the prophylactic implantable cardiac defibrillator improves the survival rate of patients with prior myocardial infarction and advanced left ventricular (LV) dysfunction. However, a more accurate noninvasive predictor should be found to identify subgroups at high risk, one that would allow implantable cardiac defibrillator therapy to be directed specifically to the patients who would benefit most.
  
  
  RESULTS
  To elucidate whether technetium 99m tetrofosmin electrocardiogram-gated single photon emission computed tomography (SPECT) imaging at rest can determine the risk of arrhythmic death, 106 patients who met the MADIT-II criteria (LV ejection fraction <or=0.3, myocardial infarction >1 month earlier, and no sustained ventricular tachyarrhythmia) were recruited from a pool of 4628 consecutive patients who had undergone resting Tc-99m tetrofosmin SPECT imaging. By use of the endpoints of lethal arrhythmic events, which included documentation of sustained ventricular tachycardia, ventricular fibrillation, or diagnosis of sudden cardiac death, we performed follow-up for a mean of 30 months. Lethal arrhythmic events occurred in 14 patients. Patients with lethal arrhythmic events had a lower LV ejection fraction, greater LV end-systolic and end-diastolic volume indices, and a greater perfusion defect volume than the remaining patients. By receiver operating characteristic curve analysis, myocardial defect volume was the strongest predictor for the development of lethal arrhythmic events.
  
  
  CONCLUSIONS
  Our results confirm that perfusion defect volume by Tc-99m tetrofosmin scintigraphy is the most pivotal predictor of the future occurrence of lethal arrhythmic events and of sudden cardiac death. Tc-99m tetrofosmin SPECT images may assist in identifying subsets of patients with a greater likelihood of arrhythmic death among patients with LV dysfunction.
authors.affiliation: Department of Cardiology, Ogaki Municipal Hospital, Ogaki, Japan.
authors.forename: Itsuro
authors.initials: I
authors.lastname: Morishima
authors.forename: Takahito
authors.initials: T
authors.lastname: Sone
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tsuboi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Mukawa
authors.forename: Michitaka
authors.initials: M
authors.lastname: Uesugi
authors.forename: Shuji
authors.initials: S
authors.lastname: Morikawa
authors.forename: Kensuke
authors.initials: K
authors.lastname: Takagi
authors.forename: Toru
authors.initials: T
authors.lastname: Niwa
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Morita
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Murakami
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Numaguchi
authors.forename: Toyoaki
authors.initials: T
authors.lastname: Murohara
authors.forename: Kenji
authors.initials: K
authors.lastname: Okumura