***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: BACKGROUND Whether remote ischemic preconditioning ( transient ischemia and reperfusion of the arm ) can improve clinical outcomes in patients undergoing coronary-artery bypass graft ( CABG ) surgery is not known . We investigated this question in a r and omized trial . METHODS We conducted a multicenter , sham-controlled trial involving adults at increased surgical risk who were undergoing on-pump CABG ( with or without valve surgery ) with blood cardioplegia .  After anesthesia induction and before surgical incision , patients were r and omly assigned to remote ischemic preconditioning ( four 5-minute inflations and deflations of a st and ard blood-pressure cuff on the upper arm ) or sham conditioning ( control group ) . Anesthetic management and perioperative care were not st and ardized . The combined primary end point was death from cardiovascular causes , nonfatal myocardial infa rct ion , coronary revascularization , or stroke , assessed 12 months after r and omization . RESULTS We enrolled a total of 1612 patients ( 811 in the control group and 801 in the ischemic-preconditioning group ) at 30 cardiac surgery centers in the United Kingdom . There was no significant difference in the cumulative incidence of the primary end point at 12 months between the patients in the remote ischemic preconditioning group and those in the control group ( 212 patients [ 26.5 % ] and 225 patients [ 27.7 % ] , respectively ; hazard ratio with ischemic preconditioning , 0.95 ; 95 % confidence interval , 0.79 to 1.15 ; P=0.58 ) . Furthermore , there were no significant between-group differences in either adverse events or the secondary end points of perioperative myocardial injury ( assessed on the basis of the area under the curve for the high-sensitivity assay of serum troponin T at 72 hours ) , inotrope score ( calculated from the maximum dose of the individual inotropic agents administered in the first 3 days after surgery ) , acute kidney injury , duration of stay in the intensive care unit and hospital , distance on the 6-minute walk test , and quality of life . CONCLUSIONS Remote ischemic preconditioning did not improve clinical outcomes in patients undergoing elective on-pump CABG with or without valve surgery . ( Funded by the Efficacy and Mechanism Evaluation Program [ a Medical Research Council and National Institute of Health Research partnership ] and the British Heart Foundation ; ERICCA Clinical Trials.gov number , NCT01247545 . ) Background : Two preconditioning stimuli should induce a more consistent overall cell protection . We hypothesized that remote ischemic preconditioning ( RIPC , second preconditioning stimulus ) applied during isoflurane inhalation ( first preconditioning stimulus ) would provide more protection to the myocardium of patients undergoing on-pump coronary artery bypass grafting . Methods : In this placebo-controlled r and omized controlled study , patients in the RIPC group received four 5-min cycles of 300 mmHg cuff inflation/deflation of the leg before aortic cross-clamping . Anesthesia consisted of opioids and propofol for induction and isoflurane for maintenance . The primary outcome was high-sensitivity cardiac troponin T release . Secondary endpoints were plasma levels of N-terminal pro-brain natriuretic peptide , high-sensitivity C-reactive protein , S100 protein , and short- and long-term clinical outcomes . Gene expression profiles were obtained from atrial tissue using microarrays . Results : RIPC ( n = 27 ) did not reduce high-sensitivity cardiac troponin T release when compared with placebo ( n = 28 ) . Likewise , N-terminal pro-brain natriuretic peptide , a marker of myocardial dysfunction ; high-sensitivity C-reactive protein , a marker of perioperative inflammatory response ; and S100 , a marker of cerebral injury , were not different between the groups . The incidence for the perioperative composite endpoint combining new arrhythmias and myocardial infa rct ions was higher in the RIPC group than the placebo group ( 14/27 vs. 6/28 , P = 0.036 ) . However , there was no difference in the 6-month cardiovascular outcome . N-terminal pro-brain natriuretic peptide release correlated with isoflurane-induced transcriptional changes in fatty-acid metabolism ( P = 0.001 ) and DNA-damage signaling ( P < 0.001 ) , but not with RIPC-induced changes in gene expression . Conclusions : RIPC applied during isoflurane inhalation provides no benefit to the myocardium of patients undergoing on-pump coronary artery bypass grafting BACKGROUND Remote ischemic preconditioning ( RIPC ) is reported to reduce biomarkers of ischemic and reperfusion injury in patients undergoing cardiac surgery , but uncertainty about clinical outcomes remains . METHODS We conducted a prospect i ve , double-blind , multicenter , r and omized , controlled trial involving adults who were scheduled for elective cardiac surgery requiring cardiopulmonary bypass under total anesthesia with intravenous propofol .  The trial compared upper-limb RIPC with a sham intervention . The primary end point was a composite of death , myocardial infa rct ion , stroke , or acute renal failure up to the time of hospital discharge . Secondary end points included the occurrence of any individual component of the primary end point by day 90 . RESULTS A total of 1403 patients underwent r and omization . The full analysis set comprised 1385 patients ( 692 in the RIPC group and 693 in the sham-RIPC group ) . There was no significant between-group difference in the rate of the composite primary end point ( 99 patients [ 14.3 % ] in the RIPC group and 101 [ 14.6 % ] in the sham-RIPC group , P=0.89 ) or of any of the individual components : death ( 9 patients [ 1.3 % ] and 4 [ 0.6 % ] , respectively ; P=0.21 ) , myocardial infa rct ion ( 47 [ 6.8 % ] and 63 [ 9.1 % ] , P=0.12 ) , stroke ( 14 [ 2.0 % ] and 15 [ 2.2 % ] , P=0.79 ) , and acute renal failure ( 42 [ 6.1 % ] and 35 [ 5.1 % ] , P=0.45 ) . The results were similar in the per- protocol analysis . No treatment effect was found in any subgroup analysis . No significant differences between the RIPC group and the sham-RIPC group were seen in the level of troponin release , the duration of mechanical ventilation , the length of stay in the intensive care unit or the hospital , new onset of atrial fibrillation , and the incidence of postoperative delirium . No  RIPC-related adverse events were observed . CONCLUSIONS Upper-limb RIPC performed while patients were under propofol-induced anesthesia did not show a relevant benefit among patients undergoing elective cardiac surgery . ( Funded by the German Research Foundation ; RIPHeart Clinical Trials.gov number , NCT01067703 . ) Background One or more brief episodes of coronary artery occlusion protect or “ precondition ” the myocardium perfused by that artery from a subsequent episode of sustained ischemia . We sought to determine whether ischemic preconditioning protects only those myocytes subjected to brief coronary occlusion or whether brief occlusions in one vascular bed also limit infa rct size and for attenuate contractile dysfunction in remote virgin myocardium subjected to subsequent sustained coronary occlusion . Methods and Results In the preliminary limb of the study , six anesthetized dogs underwent four episodes of 5-minute circumflex branch occlusion plus 5-minute reperfusion , followed by 1 hour of sustained left anterior descending coronary artery occlusion and 4.5 hours of reflow . Subendocardial blood flow during left anterior descending coronary artery occlusion ( measured by injection of radiolabeled microspheres ) was 0.07±0.03 mL. min-1 . g tissue-1 , similar to the value of 0.07±0.02 mL. min-1 . g-1 observed in a group of eight concurrent control dogs . However , infa rct size ( assessed by triphenyltetrazolium staining ) in the circumflex preconditioned group averaged 4±1 % of the myocardium at risk , significantly less ( p<0.05 ) than the value of 13 + 4 % observed in the concurrent controls . An additional 18 dogs were then r and omized to undergo either four episodes of circumflex branch occlusion ( n=8 ) or no intervention ( n=10 ) before 1 hour of left anterior descending coronary artery occlusion and 4.5 hours of reflow . Subendocardial blood flow averaged 0.08±0.02 versus 0.08±0.03 mL. min-1 . g-1 in the control versus circumflex preconditioned groups , yet infa rct size was significantly smaller in circumflex preconditioned dogs than in the controls ( 6±2 % versus 16±5 % of the risk region ; p<0.05 ) . At 4.5 hours following reperfusion , segment shortening in the left anterior descending coronary artery bed ( assessed by sonomicrometry ) averaged -21 + 19%o of baseline in control animals versus 13±12 % of baseline in the preconditioned group ( p = NS ) . Circumflex preconditioning did not , however , have an independent beneficial effect on contractile function : Regression analysis revealed that the trend toward improved function in circumflex preconditioned dogs reflected the smaller infa rct sizes in this group . Conclusions Brief episodes of ischemia in one vascular bed protect remote , virgin myocardium from subsequent sustained coronary artery occlusion in this canine model . These data imply that preconditioning may be mediated by factor(s ) activated , produced , or transported throughout the heart during brief ischemia/reperfusion Acute kidney injury ( AKI ) is a frequent complication of cardiac surgery and usually occurs in patients with preexisting chronic kidney disease ( CKD ) .  Remote ischemic preconditioning ( RIPC ) may mitigate the renal ischemia-reperfusion injury associated with cardiac surgery and may be a preventive strategy for postsurgical AKI . We undertook a r and omized controlled trial of RIPC to prevent AKI in 86 patients with CKD ( estimated glomerular filtration rate under 60 ml/min per 1.73 m(2 ) ) undergoing coronary artery bypass graft ( CABG ) surgery . Forty-three patients each were r and omized to receive st and ard care with or without RIPC consisting of three 5-minute cycles of forearm ischemia followed by reperfusion . The primary end point was the development of AKI defined as an increase in serum creatinine concentration over 0.3 mg/dl within 48 h of surgery . Secondary end points included a comparison between the study and control groups of several serum biomarkers of renal injury including cystatin-C , neutrophil gelatinase-associated lipocalin ( NGAL ) , and interleukin-18 ( IL-18 ) , and urinary biomarkers including NGAL , IL-18 , and kidney injury molecule-1 measured at 6 , 12 , and 24 h after CABG , and the 72-h serum troponin T concentration area under the curve as a marker of myocardial injury . Clinical and operative characteristics were similar between the preconditioned and control groups . AKI developed in 12 patients in both groups within 48 h of CABG . There were no significant differences between the two groups in the concentrations of any of the serum or urinary biomarkers of renal or cardiac injury after CABG . Thus , RIPC induced by forearm ischemia-reperfusion had no effect on the frequency of AKI after CABG in patients with CKD OBJECTIVES The aim of the present study was to assess the efficacy of remote ischemic post-conditioning ( RIPC ) by repeated intermittent balloon inflations in preventing  acute kidney injury ( AKI ) in patients with a non-ST-segment elevation myocardial infa rct ion undergoing percutaneous coronary intervention ( PCI ) .  BACKGROUND AKI complicating PCI is associated with increased morbidity and mortality . Remote ischemic preconditioning , using cycles of upper limb ischemia-reperfusion as a conditioning stimulus , has been recently shown to prevent AKI in patients undergoing elective coronary angiography . METHODS Eligible patients were r and omized to receive RIPC by cycles of inflation and deflation of the stent balloon during PCI or a sham procedure ( control patients ) . The primary endpoint was AKI , defined as an increase of ≥ 0.5 mg/dl or ≥ 25 % in serum creatinine within 96 h from PCI . The 30-day rate of death or re-hospitalization for any cause was one of the secondary endpoints . RESULTS A total of 225 patients were included ( median age , 68 years ; 36 % female ) .  The AKI rate in the RIPC group was 12.4 % versus 29.5 % in the control group ( p = 0.002 ; odds ratio : 0.34 ; 95 % confidence interval : 
    Output:
    
Our meta- analysis suggests that RIC for preventing AKI following CABG has faced with challenges in terms of AKI , the requirement for RRT , and mortality .
However , RIC shows a renoprotective benefit for PCI .
Hence , our findings may infer the preserved renal effects of RIC in CABG with preconditioning before the coronary angiography , or in HCR