title: Multi-scale symbolic entropy analysis provides prognostic prediction in patients receiving extracorporeal life support.
abstract: BACKGROUND
  Extracorporeal life support (ECLS) can temporarily support cardiopulmonary function, and is occasionally used in resuscitation. Multi-scale entropy (MSE) derived from heart rate variability (HRV) is a powerful tool in outcome prediction of patients with cardiovascular diseases. Multi-scale symbolic entropy analysis (MSsE), a new method derived from MSE, mitigates the effect of arrhythmia on analysis. The objective is to evaluate the prognostic value of MSsE in patients receiving ECLS. The primary outcome is death or urgent transplantation during the index admission.
  
  
  METHODS
  Fifty-seven patients receiving ECLS less than 24 hours and 23 control subjects were enrolled. Digital 24-hour Holter electrocardiograms were recorded and three MSsE parameters (slope 5, Area 6-20, Area 6-40) associated with the multiscale correlation and complexity of heart beat fluctuation were calculated.
  
  
  RESULTS
  Patients receiving ECLS had significantly lower value of slope 5, area 6 to 20, and area 6 to 40 than control subjects. During the follow-up period, 29 patients met primary outcome. Age, slope 5, Area 6 to 20, Area 6 to 40, acute physiology and chronic health evaluation II score, multiple organ dysfunction score (MODS), logistic organ dysfunction score (LODS), and myocardial infarction history were significantly associated with primary outcome. Slope 5 showed the greatest discriminatory power. In a net reclassification improvement model, slope 5 significantly improved the predictive power of LODS; Area 6 to 20 and Area 6 to 40 significantly improved the predictive power in MODS. In an integrated discrimination improvement model, slope 5 added significantly to the prediction power of each clinical parameter. Area 6 to 20 and Area 6 to 40 significantly improved the predictive power in sequential organ failure assessment.
  
  
  CONCLUSIONS
  MSsE provides additional prognostic information in patients receiving ECLS.
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. austinr34@gmail.com.
authors.forename: Yen-Hung
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. hchuangster@ntuh.gov.tw.
authors.forename: Hui-Chun
authors.initials: HC
authors.lastname: Huang
authors.affiliation: Graduate Institute of Communication Engineering, National Taiwan University, Taipei, Taiwan. tako0215@hotmail.com.
authors.forename: Yi-Chung
authors.initials: YC
authors.lastname: Chang
authors.affiliation: Research Center for Adaptive Data Analysis, National Central University, No. 300, Jhongda Rd, Taoyuan County, 32001, Taiwan. dreamtheater.lin@gmail.com.
authors.forename: Chen
authors.initials: C
authors.lastname: Lin
authors.affiliation: Research Center for Adaptive Data Analysis, National Central University, No. 300, Jhongda Rd, Taoyuan County, 32001, Taiwan. mzlo@ncu.edu.tw.
authors.forename: Men-Tzung
authors.initials: MT
authors.lastname: Lo
authors.affiliation: Department of Agronomy, Biometry Division, National Taiwan University, Taipei, Taiwan. lyliu@ntu.edu.tw.
authors.forename: Li-Yu Daisy
authors.initials: LY
authors.lastname: Liu
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. pirutsai@yahoo.com.tw.
authors.forename: Pi-Ru
authors.initials: PR
authors.lastname: Tsai
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. yschen1234@gmail.com.
authors.forename: Yih-Sharng
authors.initials: YS
authors.lastname: Chen
authors.affiliation: Department of Surgery, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. kowj@ntu.edu.tw.
authors.forename: Wen-Je
authors.initials: WJ
authors.lastname: Ko
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. ylho@ntu.edu.tw.|Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, 7 Chung-Shan South Road, Taipei, Taiwan. ylho@ntu.edu.tw.
authors.forename: Yi-Lwun
authors.initials: YL
authors.lastname: Ho
authors.affiliation: Department of Internal Medicine, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan. mfchen@ntuh.gov.tw.
authors.forename: Ming-Fong
authors.initials: MF
authors.lastname: Chen
authors.affiliation: Research Center for Adaptive Data Analysis, National Central University, No. 300, Jhongda Rd, Taoyuan County, 32001, Taiwan. ckpeng@comcast.net.|Division of Interdisciplinary Medicine and Biotechnology, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, Massachusetts, USA. ckpeng@comcast.net.
authors.forename: Chung-Kang
authors.initials: CK
authors.lastname: Peng
authors.affiliation: Department of Surgery, Emory University School of Medicine, Atlanta, Georgia, USA. tbuchma@emory.edu.
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Buchman
mesh_terms: D000328:Adult; D000368:Aged; D019277:Entropy; D005112:Extracorporeal Circulation / Q000379:methods* / Q000706:statistics & numerical data; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008021:Life Support Systems / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies