title: Impact of remote ischaemic preconditioning on major clinical outcomes in patients undergoing cardiovascular surgery: A meta-analysis with trial sequential analysis of 32 randomised controlled trials.
abstract: BACKGROUND
  The impact of remote ischaemic preconditioning (RIPC) on major clinical outcomes in patients undergoing cardiovascular surgery remains controversial. We systematically reviewed the available evidence to evaluate the potential benefits of RIPC in such patients.
  
  
  METHODS
  PubMed, Embase, and Cochrane Library databases were searched for relevant randomised controlled trials (RCTs) conducted between January 2006 and March 2016. The pooled population of patients who underwent cardiovascular surgery was divided into the RIPC and control groups. Trial sequential analysis was applied to judge data reliability. The pooled relative risks (RRs) with 95% confidence intervals (CIs) between the groups were calculated for all-cause mortality, major adverse cardiovascular and cerebral events (MACCEs), myocardial infarction (MI), and renal failure.
  
  
  RESULTS
  RIPC was not associated with improvement in all-cause mortality (RR, 1.04; 95%CI, 0.82-1.31; I2=26%; P>0.05) or MACCE incidence (RR, 0.90; 95%CI, 0.71-1.14; I2=40%; P>0.05) after cardiovascular surgery, and both results were assessed by trial sequential analysis as sufficient and conclusive. Nevertheless, RIPC was associated with a significantly lower incidence of MI (RR, 0.87; 95%CI, 0.76-1.00; I2=13%; P≤0.05). However, after excluding a study that had a high contribution to heterogeneity, RIPC was associated with increased rates of renal failure (RR, 1.53; 95%CI, 1.12-2.10; I2=5%; P≤0.05).
  
  
  CONCLUSIONS
  In patients undergoing cardiovascular surgery, RIPC reduced the risk for postoperative MI, but not that for MACCEs or all-cause mortality, a discrepancy likely related to the higher rate of renal failure associated with RIPC.
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Shifei
authors.initials: S
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Hairui
authors.initials: H
authors.lastname: Li
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Nvqin
authors.initials: N
authors.lastname: He
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Yili
authors.initials: Y
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Shengcun
authors.initials: S
authors.lastname: Guo
authors.affiliation: Department of Oncology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Wangjun
authors.initials: W
authors.lastname: Liao
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Yulin
authors.initials: Y
authors.lastname: Liao
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China. Electronic address: yanmei0812@126.com.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Organ Failure Research, Department of Cardiology, Nanfang Hospital, Southern Medical University, Guangzhou, China. Electronic address: jianpingbin@126.com.
authors.forename: Jianping
authors.initials: J
authors.lastname: Bin
mesh_terms: D013504:Cardiovascular Surgical Procedures / Q000009:adverse effects / Q000401:mortality / Q000639:trends*; D006801:Humans; D019157:Ischemic Preconditioning, Myocardial / Q000379:methods / Q000401:mortality / Q000639:trends*; D011183:Postoperative Complications / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D015203:Reproducibility of Results
keywords: Cardiovascular surgery; Clinical outcomes; Meta-analysis; Randomised controlled trial; Remote ischemic preconditioning