title: Selective improvement in Seattle Heart Failure Model risk stratification using iodine-123 meta-iodobenzylguanidine imaging.
abstract: BACKGROUND
  The Seattle Heart Failure Model (SHFM) is a multivariable model that uses demographic and clinical markers to predict survival in patients with heart failure. Inappropriate activation of the sympathetic nervous system, which contributes to the progression of heart failure and increased mortality, can be assessed using iodine-123 meta-iodobenzylguanidine (MIBG) cardiac imaging. This study investigated the incremental value of MIBG cardiac imaging when added to the SHFM for prediction of all-cause mortality.
  
  
  METHODS
  Survival data from 961 NYHA II-III subjects in the ADMIRE-HFX trial were included in this analysis. The predictive value of the SHFM alone and in combination with MIBG heart-to-mediastinum ratio (H/M) was compared for all-cause mortality (101 deaths during a median follow-up of 2 years).
  
  
  RESULTS
  The addition of H/M to the SHFM in a Cox model significantly improved risk prediction (P < .0001), with a greater utility in higher risk SHFM patients. The observed 2-year mortality in the highest-risk SHFM subjects (rounded SHFM score of 1) was 24%, but varied from 46% with H/M <1.2 to 0% with H/M >1.8. Net reclassification improvement was 22.7% (P < .001), with 14.9% of subjects who died reclassified into a higher risk category than suggested by SHFM score alone (P = .01) and 7.9% of subjects who survived reclassified into a lower risk category (P < .0001). The 2-year integrated discrimination improvement (+4.14%, P < .0001) and the 1-year area under the receiver-operator characteristic curve (+0.04, P = .026) both showed significant improvement for the combined model with H/M compared to the SHFM alone.
  
  
  CONCLUSIONS
  The addition of MIBG imaging to the SHFM improves risk stratification, especially in higher risk patients. MIBG may have clinical utility in higher risk patients who are being considered for devices such as ICD, CRT-D, LVAD, and cardiac transplantation.
authors.affiliation: Division of Cardiology, University of Washington, 1959 NE Pacific Street, PO Box 356422, Seattle, WA, USA. eketchum@washington.edu
authors.forename: Eric S
authors.initials: ES
authors.lastname: Ketchum
authors.forename: Arnold F
authors.initials: AF
authors.lastname: Jacobson
authors.forename: James H
authors.initials: JH
authors.lastname: Caldwell
authors.forename: Roxy
authors.initials: R
authors.lastname: Senior
authors.forename: Manuel D
authors.initials: MD
authors.lastname: Cerqueira
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Thomas
authors.forename: Denis
authors.initials: D
authors.lastname: Agostini
authors.forename: Jagat
authors.initials: J
authors.lastname: Narula
authors.forename: Wayne C
authors.initials: WC
authors.lastname: Levy
mesh_terms: D019797:3-Iodobenzylguanidine; D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000401:mortality / Q000628:therapy; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012306:Risk
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine