Background: Novel cardioprotective strategies are required to improve clinical outcomes in higher-risk patients undergoing coronary artery bypass graft (CABG) with or without valve surgery. Remote ischaemic preconditioning (RIPC) in which brief episodes of non-lethal ischaemia and reperfusion are applied to the arm or leg has been demonstrated to reduce perioperative myocardial injury (PMI) following CABG with or without valve surgery.
Objective: To investigate whether or not RIPC can improve clinical outcomes in this setting in the Effect of Remote Ischaemic preconditioning on Clinical outcomes in patients undergoing Coronary Artery bypass graft surgery (ERICCA) study in patients undergoing CABG surgery.
Design: Multicentre, double-blind, randomised sham controlled trial.
Setting: The study was conducted across 30 cardiothoracic centres in the UK between March 2010 and March 2015.
Participants: Eligible patients were higher-risk adult patients (aged > 18 years of age; additive European System for Cardiac Operative Risk of ≥ 5) undergoing on-pump CABG with or without valve surgery with blood cardioplegia.
Interventions: Patients were randomised to receive either RIPC (four 5-minute inflations/deflations of a standard blood pressure cuff placed on the upper arm) or the sham control procedure (simulated RIPC protocol) following anaesthetic induction and prior to surgical incision. Anaesthetic management and perioperative care were not standardised.
Main outcome measures: The combined primary end point was the rate of major adverse cardiac and cerebral events comprising cardiovascular death, myocardial infarction, coronary revascularisation and stroke within 12 months of randomisation. Secondary end points included perioperative myocardial and acute kidney injury (AKI), intensive care unit and hospital stay, inotrope score, left ventricular ejection fraction, changes in quality of life and exercise tolerance.
Results: In total, 1612 patients (sham control group, n = 811; RIPC group, n = 801) were randomised in 30 cardiac surgery centres in the UK. There was no difference in the primary end point at 12 months between the RIPC group and the sham control group (26.5% vs. 27.7%; hazard ratio 0.95, 95% confidence interval 0.79 to 1.15; p = 0.58). Furthermore, there was no evidence for any differences in either adverse events or the secondary end points of PMI (72-hour area under the curve for serum high-sensitivity troponin T), inotrope score, AKI, intensive therapy unit and hospital stay, 6-minute walk test and quality of life.
Conclusions: In patients undergoing elective on-pump CABG with or without valve surgery, without standardisation of the anaesthetic regimen, RIPC using transient arm ischaemia–reperfusion did not improve clinical outcomes. It is important that studies continue to investigate the potential mechanisms underlying RIPC, as this may facilitate the translation of this simple, non-invasive, low-cost intervention into patient benefit. The limitations of the study include the lack of standardised pre-/perioperative anaesthesia and medication, the level of missing and incomplete data for some of the secondary end points and the incompleteness of the data for the echocardiography substudy.
Trial registration: ClinicalTrials.gov NCT01247545.
Funding: This project was funded by the Efficacy and Mechanism Evaluation programme, a MRC and NIHR partnership, and the British Heart Foundation.
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Effect of remote ischemic preconditioning on clinical outcomes in patients undergoing coronary artery bypass graft surgery (ERICCA): rationale and study design of a multi-centre randomized double-blinded controlled clinical trial.Clin Res Cardiol. 2012 May;101(5):339-48. doi: 10.1007/s00392-011-0397-x. Epub 2011 Dec 21. Clin Res Cardiol. 2012. PMID: 22186969 Clinical Trial.
Remote Ischemic Preconditioning and Outcomes of Cardiac Surgery.N Engl J Med. 2015 Oct 8;373(15):1408-17. doi: 10.1056/NEJMoa1413534. Epub 2015 Oct 5. N Engl J Med. 2015. PMID: 26436207 Clinical Trial.
Effect of remote ischaemic preconditioning on clinical outcomes in patients undergoing cardiac bypass surgery: a randomised controlled clinical trial.Heart. 2015 Feb;101(3):185-92. doi: 10.1136/heartjnl-2014-306178. Epub 2014 Sep 24. Heart. 2015. PMID: 25252696 Clinical Trial.
Remote ischaemic preconditioning for coronary artery bypass grafting (with or without valve surgery).Cochrane Database Syst Rev. 2017 May 5;5(5):CD011719. doi: 10.1002/14651858.CD011719.pub3. Cochrane Database Syst Rev. 2017. PMID: 28475274 Free PMC article. Review.
REmote preconditioning for Protection Against Ischaemia–Reperfusion in renal transplantation (REPAIR): a multicentre, multinational, double-blind, factorial designed randomised controlled trial.Southampton (UK): NIHR Journals Library; 2015 May. NIHR Journals Library. 2015. PMID: 26020087 Free Books & Documents. Review.