title: The relationship of left ventricular mechanical dyssynchrony and cardiac sympathetic denervation to potential sudden cardiac death events in systolic heart failure.
abstract: BACKGROUND
  Patients with heart failure (HF) are at increased risk for left ventricular (LV) dyssynchrony which is associated with sudden cardiac death (SCD). This study examined the association of LV mechanical dyssynchrony and cardiac sympathetic denervation with potential SCD events in symptomatic patients with HF and reduced ejection fraction (HFrEF).
  
  
  METHODS
  Of the 917 HFrEF patients in ADMIRE-HF, 92 experienced adjudicated potential SCD events during a 17 months median follow-up. Propensity scores were used to assemble a matched cohort of 85 pairs of patients with and without potential SCD events. ADMIRE-HF subjects had rest gated SPECT Tc-99m and I-123 MIBG imaging. Perfusion images were processed using phase analysis software to derive phase standard deviation (SD), an index of mechanical dyssynchrony.
  
  
  RESULTS
  Of the 92 patients who experienced adjudicated potential SCD events 23 had SCD, 5 fatal myocardial infarction, 7 resuscitated cardiac arrest, 46 had appropriate ICD therapy, and 11 had sustained ventricular tachycardia. Patients who experienced potential SCD events had significantly wider phase SD than matched control patients (62.3 ± 2.4º vs 55.5 ± 2.3º, P = .03) and were more likely to have a phase SD ≥ 60º (53 % vs 35 %, P = .03). Fewer patients with potential SCD events (6 % vs 15 % of the controls, P = .08) had an MIBG heart/mediastinum uptake-ratio ≥1.6.
  
  
  CONCLUSIONS
  Among symptomatic HFrEF patients, LV mechanical dyssynchrony is independently associated with potential SCD events. Phase analysis may provide incremental prognostic information on top of current indicators of SCD risk in HFrEF.
authors.affiliation: University of Alabama at Birmingham, Zeigler Research Building 1024, 703 19th Street South, Birmingham, AL, 35294, USA, fadihage@uab.edu.
authors.forename: Fadi G
authors.initials: FG
authors.lastname: Hage
authors.forename: Himanshu
authors.initials: H
authors.lastname: Aggarwal
authors.forename: Kanan
authors.initials: K
authors.lastname: Patel
authors.forename: Ji
authors.initials: J
authors.lastname: Chen
authors.forename: Arnold F
authors.initials: AF
authors.lastname: Jacobson
authors.forename: Jaekyeong
authors.initials: J
authors.lastname: Heo
authors.forename: Ali
authors.initials: A
authors.lastname: Ahmed
authors.forename: Ami E
authors.initials: AE
authors.lastname: Iskandrian
mesh_terms: D019797:3-Iodobenzylguanidine; D000368:Aged; D015331:Cohort Studies; D016757:Death, Sudden, Cardiac; D005260:Female; D005500:Follow-Up Studies; D006321:Heart / Q000000981:diagnostic imaging; D054143:Heart Failure, Systolic / Q000000981:diagnostic imaging* / Q000401:mortality; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009474:Neurons / Q000473:pathology; D010477:Perfusion; D011379:Prognosis; D012984:Software; D013564:Sympathetic Nervous System / Q000503:physiopathology; D013667:Technetium; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
chemical_list: D019797:3-Iodobenzylguanidine; D013667:Technetium