title: Electrocardiogram-based predictors of clinical outcomes: a meta-analysis of the prognostic value of ventricular repolarization.
abstract: OBJECTIVE
  To estimate age- and sex-specific prognostic values of eight electrocardiographic repolarization descriptors to predict various mortality endpoints.
  
  
  BACKGROUND
  Using electrocardiographic markers for risk stratification is well studied; however, the prognostic value of many markers is controversial, and their clinical utility remains debatable. No meta-analyses exist that address the prognostic value of ECG markers.
  
  
  METHODS
  Data were synthesized from 106 primary studies using a random-effect variance model. Age and sex subgroups were analyzed using sensitivity analysis.
  
  
  RESULTS
  Four classic (i.e., duration, amplitude, inversion, and ST-T changes) and four novel (i.e., axis, loop, wavefront direction, and waveform complexity) repolarization descriptors were studied. These novel descriptors were particularly useful in predicting sudden death. Abnormal repolarization duration, vectors, and loops have greater impact on negative cardiovascular outcomes in women compared to men; additionally, ischemic repolarization changes have greater impact on negative cardiovascular outcomes in younger versus older adults.
  
  
  CONCLUSIONS
  Assessing repolarization abnormalities is particularly helpful in women and younger adults. Researchers need to further explore the clinical utility of these abnormalities in management algorithms.
authors.affiliation: University of Pittsburgh, Pittsburgh, PA, USA. Electronic address: ssa33@pitt.edu.
authors.forename: Salah S
authors.initials: SS
authors.lastname: Al-Zaiti
authors.affiliation: The State University of New York University at Buffalo, Buffalo, NY, USA; The VA of WNY Healthcare System, Buffalo, NY, USA.
authors.forename: James A
authors.initials: JA
authors.lastname: Fallavollita
authors.affiliation: The State University of New York University at Buffalo, Buffalo, NY, USA.
authors.forename: Yow-Wu B
authors.initials: YW
authors.lastname: Wu
authors.affiliation: The State University of New York University at Buffalo, Buffalo, NY, USA.
authors.forename: Machiko R
authors.initials: MR
authors.lastname: Tomita
authors.affiliation: The Strong Memorial Hospital at University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Mary G
authors.initials: MG
authors.lastname: Carey
mesh_terms: D000367:Age Factors; D000368:Aged; D002318:Cardiovascular Diseases / Q000401:mortality / Q000503:physiopathology*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012306:Risk; D012737:Sex Factors
keywords: Electrocardiogram; Meta-analysis; Mortality; Repolarization