title: Identifying patients with less potential to benefit from implantable cardioverter-defibrillator therapy: comparison of the performance of four risk scoring systems.
abstract: OBJECTIVE
  Patients at high non-sudden cardiac death risk may gain no significant benefit from implantable cardioverter-defibrillator (ICD) therapy. A number of approaches have been proposed to identify these patients, including single clinical markers and more complex scoring systems. The aims of this study were to use the proposed scoring systems to (1) establish how many current ICD recipients may be too high risk to derive significant benefit from ICD therapy and (2) evaluate how well the scoring systems predict short-term mortality in an unselected ICD cohort.
  
  
  METHODS
  We performed a single-centre retrospective observational study of all new ICD implants over 5 years (2009-2013). We used four published scoring systems (Bilchick, Goldenberg, Kramer and Parkash) and serum urea to identify new ICD recipients whose short-term predicted mortality risk was high. We evaluated how well the scoring systems predicted death.
  
  
  RESULTS
  Over 5 years, there were 406 new implants (79% male, mean age 70 (60-76), 58% primary prevention). During a follow-up of 936 ± 560 days, 96 patients died. Using the scoring systems, the proportion of ICD recipients predicted to be at high short-term mortality risk were 5.9% (Bilchick), 34.7% (Goldenberg), 7.4% (Kramer), 21.4% (Parkash) and 25% (urea, cut-off of >9.28 mM). All four risk scores predicted mortality (P < 0.0001); however, none outperformed urea for the prediction of 1- or 3-year mortality.
  
  
  CONCLUSIONS
  Using published scoring systems, a significant proportion of current ICD recipients are at high short-term mortality risk. Although all four scoring systems predicted mortality during follow-up, none significantly outperformed serum urea.
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK. amitkaura@nhs.net.|Hammersmith Hospital, Du Cane Road, London, W12 0HS, UK. amitkaura@nhs.net.
authors.forename: Amit
authors.identifier: http://orcid.org/0000-0003-4613-4656
authors.initials: A
authors.lastname: Kaura
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Sunderland
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Ravi
authors.initials: R
authors.lastname: Kamdar
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Edward
authors.initials: E
authors.lastname: Petzer
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Theresa
authors.initials: T
authors.lastname: McDonagh
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Francis
authors.initials: F
authors.lastname: Murgatroyd
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Para
authors.initials: P
authors.lastname: Dhillon
authors.affiliation: King's College Hospital, Denmark Hill, London, SE5 9RS, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Scott
mesh_terms: D000368:Aged; D015415:Biomarkers; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D005260:Female; D006801:Humans; D008131:London; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D011322:Primary Prevention; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors
chemical_list: D015415:Biomarkers
keywords: Implantable cardioverter-defibrillator; Mortality; Scoring system; Urea