title: Extracorporeal life support and survival after out-of-hospital cardiac arrest in a nationwide registry: A propensity score-matched analysis.
abstract: BACKGROUND
  The benefit of extracorporeal life support (ECLS) in highly selective patients with out-of-hospital cardiac arrest (OHCA) is supported by previous studies; however, it is unclear whether the effects of ECLS are observed at a population level. This study aimed to determine whether ECLS is associated with improved survival outcomes compared to conventional CPR (cardiopulmonary resuscitation) at a national level.
  
  
  METHODS
  We used a Korean national OHCA cohort database from 2009 to 2013. The inclusion criteria were OHCA adults with presumed cardiac aetiology and resuscitation by emergency medical services (EMS). Patients were excluded if their information on prehospital time intervals or clinical outcomes at hospital discharge was incomplete or not captured. The primary outcome was neurologically favourable survival to discharge. We compared the primary outcomes between the ECLS and non-ECLS groups using a multivariable logistic regression and a propensity score matching analysis.
  
  
  RESULTS
  Of the 119,077 patients with OHCA, 36,547 were included in the analysis. There were 320 patients who received ECLS. There was no significant difference in neurologically favourable survival to discharge between the ECLS group and the non-ECLS group after adjusting for covariates (adjusted OR, 0.65; 95% CI, 0.41-1.04). In the propensity score-matched cohort, there was also no significant difference between the two groups (adjusted OR, 0.94; 95% CI, 0.41-2.14).
  
  
  CONCLUSIONS
  In this propensity score-matched cohort using a nationwide OHCA database, OHCA victims who received ECLS did not show better survival outcomes than those who did not receive ECLS.
authors.affiliation: Dept. of Emergency Medicine, Seoul National University Bundang Hospital, 166 Gumi-ro Bundang-gu, Seongnam 463-707, Republic of Korea. Electronic address: emergencychoi@gmail.com.
authors.forename: Dong Sun
authors.initials: DS
authors.lastname: Choi
authors.affiliation: Biomedical Research Institute, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea; Dept. of Emergency Medicine, Gyeongsang National University Hospital, 79 Gangnam-ro, Jinju-si, Gyeongsangnam-do 52727, Republic of Korea. Electronic address: emkity@gmail.com.
authors.forename: Taeyun
authors.initials: T
authors.lastname: Kim
authors.affiliation: Biomedical Research Institute, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: ro.youngsun7@gmail.com.
authors.forename: Young Sun
authors.initials: YS
authors.lastname: Ro
authors.affiliation: Biomedical Research Institute, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: arendt@gmail.com.
authors.forename: Ki Ok
authors.initials: KO
authors.lastname: Ahn
authors.affiliation: Dept. of Emergency Medicine, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: ironlyj@gmail.com.
authors.forename: Eui Jung
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Dept. of Social Medicine, Inha University School of Medicine, 27 Inhang-ro Jung-gu, Incheon 400-711, Republic of Korea. Electronic address: cyberdoc73@gmail.com.
authors.forename: Seung Sik
authors.initials: SS
authors.lastname: Hwang
authors.affiliation: Dept. of Emergency Medicine, Jeju National University Hospital, 15 Aran13-gil, Jeju-si, Jeju 63241, Republic of Korea. Electronic address: sungwook78@gmail.com.
authors.forename: Sung Wook
authors.initials: SW
authors.lastname: Song
authors.affiliation: Dept. of Emergency Medicine, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: skciva@gmail.com.
authors.forename: Kyoung Jun
authors.initials: KJ
authors.lastname: Song
authors.affiliation: Dept. of Emergency Medicine, Seoul National University Hospital, 101 Daehak-ro Jongno-gu, Seoul 110-744, Republic of Korea. Electronic address: shinsangdo@medimail.co.kr.
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Shin
mesh_terms: D000368:Aged; D016887:Cardiopulmonary Resuscitation; D015331:Cohort Studies; D015199:Extracorporeal Membrane Oxygenation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D010351:Patient Discharge; D057216:Propensity Score; D012042:Registries; D056910:Republic of Korea; D012189:Retrospective Studies; D015996:Survival Rate
keywords: Extracorporeal circulation; Out-of-hospital cardiac arrest; Propensity score; Survival