title: Effects of delayed remote ischemic preconditioning on peri-operative myocardial injury in patients undergoing cardiac surgery - A randomized controlled trial.
abstract: BACKGROUND
  Remote ischemic preconditioning (RIPC) has two time windows for organ protection: acute and delayed. Previous studies have mainly focused on the acute time window to evaluate organ protection by RIPC. We evaluated myocardial protection by delayed RIPC in adult patients undergoing cardiac surgery.
  
  
  METHODS
  A total of 160 adult patients undergoing cardiac surgery with cardiopulmonary bypass were randomized to receive either delayed RIPC (four cycles of 5min of ischemia followed by 5min of reperfusion by inflation to 200mmHg and deflation of a blood pressure cuff on the upper arm) or the control treatment 24-48h before surgery. The primary endpoint was post-operative troponin I levels serially measured for 72h. Secondary endpoints included post-operative serum creatinine levels, acute kidney injury, and composite complications.
  
  
  RESULTS
  There were no significant differences in post-operative troponin I values. The incidence of acute kidney injury, defined by the Acute Kidney Injury Network staging system, was lower in the delayed RIPC group compared to the control group (30.0% vs. 47.5%; relative risk, 0.768; 95% confidence interval, 0.599-0.985; p=0.023). Moreover, the occurrence of composite complications was lower in the delayed RIPC group compared with the control group (65.0% vs. 81.3%; relative risk, 0.536; 95% confidence interval, 0.311-0.924; p=0.020).
  
  
  CONCLUSIONS
  While RIPC did not provide cardioprotective effects in patients undergoing cardiac surgery, it appeared to reduce acute kidney injury, as well as the rate of composite complications.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Tae Kyong
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Jeong Jin
authors.initials: JJ
authors.lastname: Min
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Youn Joung
authors.initials: YJ
authors.lastname: Cho
authors.affiliation: The Hatter Cardiovascular Institute, University College London, London, UK; The National Institute of Health Research, University College London Hospitals Biomedical Research Center, London, UK; National Heart Research Institute Singapore, National Heart Center Singapore, Singapore, Singapore; Cardiovascular and Metabolic Disorders Program, Duke-National University of Singapore, Singapore, Singapore.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Hausenloy
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Hyuk
authors.initials: H
authors.lastname: Ahn
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Kyung-Hwan
authors.initials: KH
authors.lastname: Kim
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Ho Young
authors.initials: HY
authors.lastname: Hwang
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Deok Man
authors.initials: DM
authors.lastname: Hong
authors.affiliation: Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea. Electronic address: jeonyunseok@gmail.com.
authors.forename: Yunseok
authors.initials: Y
authors.lastname: Jeon
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D000367:Age Factors; D000368:Aged; D000704:Analysis of Variance; D019540:Area Under Curve; D006348:Cardiac Surgical Procedures / Q000379:methods* / Q000401:mortality; D002315:Cardiopulmonary Bypass / Q000379:methods* / Q000401:mortality; D004311:Double-Blind Method; D005260:Female; D017052:Hospital Mortality; D006785:Hospitals, University; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015428:Myocardial Reperfusion Injury / Q000517:prevention & control*; D011182:Postoperative Care; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D011379:Prognosis; D056910:Republic of Korea; D018570:Risk Assessment; D012737:Sex Factors; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D016896:Treatment Outcome; D020107:Troponin T / Q000097:blood*
chemical_list: D020107:Troponin T
keywords: Cardiac surgery; Cardioprotection; Preconditioning; Remote ischemic preconditioning