Remote ischemic postconditioning as a strategy to reduce acute kidney injury during primary PCI: a post-hoc analysis of a randomized trial

Contrast-Associated Acute Kidney Injury

Contrast-associated acute kidney injury (CA-AKI) is an impairment of renal function, which occurs within days of intravascular administration of iodinated contrast media. Taking into account that minimally invasive cardiac interventions are becoming increasingly popular, compared to traditional surgery, given their impact on prognosis and costs, CA-AKI remains a subject of increasing interest for patients and physicians. This review summarizes the epidemiology and risk stratification, diagnostic criteria, pathophysiology and clinical implications of CA-AKI, providing evidence for the most studied preventive strategies.

Acute Renal Failure/Acute Kidney Injury (AKI) Associated with Endovascular Procedures

AKI is one of the most common yet underdiagnosed postoperative complications that can occur after any type of surgery. Contrast-induced nephropathy (CIN) is still poorly defined and due to a wide range of confounding individual variables, its risk is difficult to determine. CIN mainly affects patients with underlying chronic kidney disease, diabetes, sepsis, heart failure, acute coronary syndrome and cardiogenic shock. Further research is necessary to better understand pathophysiology of contrast-induced AKI and consequent implementation of effective prevention and therapeutic strategies. Although many therapies have been tested to avoid CIN, the only potent preventative strategy involves aggressive fluid administration and reduction of contrast volume. Regardless of surgical technique—open or endovascular—perioperative AKI is associated with significant morbidity, mortality and cost. Endovascular procedures always require administration of a contrast media, which may cause acute tubular necrosis or renal vascular embolization leading to renal ischemia and as a consequence, contribute to increased number of post-operative AKIs.

Renoprotective effect of remote ischemic postconditioning in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

Background

Whether upper arm remote ischemic postconditioning (RIPostC) exerts protection to kidney in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) remains unknown.

Methods

Sixty-four patients with STEMI were randomized to PPCI + RIPostC (n=29) and PPCI (n=35) groups. RIPostC consisting of 4 cycles of 5 minutes occlusion/reperfusion by cuff inflation/deflation of the upper arm was started within 1 minute after the first balloon dilatation. Peripheral venous blood samples were collected before PPCI and at 0.5, 8, 24, 48, and 72 hours after PPCI to detect serum creatinine (SCr) and creatine kinase-MB (CK-MB). Acute kidney injury (AKI) rate and estimated glomerular filtration rate (eGFR) were calculated. The transthoracic echocardiography was performed 7 days after PPCI to assess left ventricular ejection fraction (LVEF).

Results

The patients in the PPCI + RIPostC group had a lower AKI rate compared with those in the PPCI group (P=0.04). The eGFR after PPCI increased in the PPCI + RIPostC group compared to the PPCI group (P<0.01). The peak of CK-MB concentration in the PPCI + RIPostC group was significantly lower than that in the PPCI group (P<0.01). The area under the curve of CK-MB decreased in the PPCI + RIPostC group compared with that in the PPCI group. LVEF in the PPCI + RIPostC group was significantly higher than that in the PPCI group (P=0.04).

Conclusion

Upper arm RIPostC exerts renal and cardiac protection following cardiac ischemia–reperfusion in patients with STEMI.

Remote Ischemic Postconditioning (RIPC) of the Upper Arm Results in Protection from Cardiac Ischemia-Reperfusion Injury Following Primary Percutaneous Coronary Intervention (PCI) for Acute ST-Segment Elevation Myocardial Infarction (STEMI)

BACKGROUND The aim of this study was to evaluate the role of remote ischemic postconditioning (RIPC) of the upper arm on protection from cardiac ischemia-reperfusion injury following primary percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). MATERIAL AND METHODS Eighty patients with STEMI were randomized into two groups: primary PCI (N=44) and primary PCI+RIPC (N=36). RIPC consisted of four cycles of 5 minutes of occlusion and five minutes of reperfusion by cuff inflation and deflation of the upper arm, commencing within one minute of the first PCI balloon dilatation. Peripheral venous blood samples were collected before PCI and at 0.5, 8, 24, 48, and 72 hours after PCI. Levels of creatine kinase-MB (CK-MB), serum creatinine (Cr), nitric oxide (NO), and stromal cell-derived factor-1α (SDF-1α) were measured. The rates of acute kidney injury (AKI) and the estimated glomerular filtration rate (eGFR) were calculated. RESULTS Patients in the primary PCI+RIPC group, compared with the primary PCI group, had significantly lower peak CK-MB concentrations (P<0.01), a significantly increased left ventricular ejection fraction (LVEF) (P=0.01), a significantly lower rate of AKI (P<0.01) a significantly increased eGFR (P<0.01), and decreased area under the curve (AUC) of CK-MB, NO and SDF-1α. CONCLUSIONS RIPC of the upper arm following primary PCI in patients with acute STEMI might provide cardiac and renal protection from ischemia-reperfusion injury via the actions of SDF-1α, and NO.

Remote ischemic conditioning improves myocardial parameters and clinical outcomes during primary percutaneous coronary intervention: a meta-analysis of randomized controlled trials

We conducted a systematic review and meta-analysis to evaluate the effects of remote ischemic conditioning on myocardial parameters and clinical outcomes in ST segment elevation acute myocardial infarction (STEMI) patients undergoing primary percutaneous coronary intervention. Ten eligible randomized controlled trials with 1006 STEMI patients were identified. Compared with controls, remote ischemic conditioning reduced the myocardial enzyme levels (standardized mean difference =-0.86; 95% CI: -1.44 to -0.28; P = 0.004; I2 = 94.5%), and increased the incidence of complete ST-segment resolution [odds ratio (OR) = 1.74; 95% CI: 1.09 to 2.77; P = 0.02; I2 = 47.9%]. Remote ischemic conditioning patients had a lower risk of all-cause mortality (OR = 0.27; 95% CI: 0.12 to 0.62; P = 0.002; I2 = 0.0%) and lower major adverse cardiovascular and cerebrovascular events rate (OR=0.45; 95% CI: 0.27 to 0.75; P = 0.002; I2 = 0.0%). Meta-analysis suggested that remote ischemic conditioning conferred cardioprotection by reducing myocardial enzymes and increasing the incidence of complete ST-segment resolution in patients after STEMI. As a result, clinical outcomes were improved in terms of mortality and incidence of major adverse cardiovascular and cerebrovascular events.

Remote ischemic conditioning for the prevention of contrast-induced acute kidney injury in patients undergoing intravascular contrast administration: a meta-analysis and trial sequential analysis of 16 randomized controlled trials

Objective

We conducted this meta-analysis to examine the effect of remote ischemic conditioning (RIC) on contrast-induced acute kidney injury (CI-AKI) in patients undergoing intravascular contrast administrationon.

Methods

Pubmed, Embase, and Cochrane Library were comprehensively searched to identify all eligible studies by 15th March, 2017. Risk ratio (RR) and weighted mean difference with the corresponding 95% confidence intervals (CI) were used to examine the treatment effect. The heterogeneity and statistical significance were assessed with Q-test and Z-test, respectively.

Results

A total of 16 RCTs including 2175 patients were eventually analyzed. Compared with the control group, RIC could significantly decrease the incidence of CI-AKI (RR=0.58; 95% CI: 0.46, 0.74; P < 0.001), which was further confirmed by the trial sequential analysis. Subgroup analyses showed that remote ischemic preconditioning (RIPrC) and remote ischemic postconditioning (RIPoC) were both obviously effective, and perioperative hydration might enhance the efficiency of RIC. RIC also significantly reduced the major adverse cardiovascular events within six months.

Conclusion

RIC, whether RIPrC or RIPoC, could effectively exert renoprotective role in intravascular contrast administration and reduce the incidence of relevant adverse events.

Impact of Remote Ischemic Postconditioning during Primary Percutaneous Coronary Intervention on Left Ventricular Remodeling after Anterior Wall ST-Segment Elevation Myocardial Infarction: A Single-Center Experience

The role of remote ischemic postconditioning (RIPostC) in improving left ventricular (LV) remodeling after primary percutaneous coronary intervention (PCI) is not well established. To determine the efficacy and safety of RIPostC in improving LV remodeling and cardiovascular outcomes after primary PCI for anterior ST-elevation myocardial infarction (STEMI). Seventy-one patients with anterior STEMI were randomized to primary PCI with RIPostC protocol ( n  = 36) versus conventional primary PCI ( n  = 35). Primary outcomes included LV remodeling and LV ejection fraction (LVEF) at 6 month follow-up using transthoracic echocardiography. Secondary outcomes included infarct size, ST-segment resolution (STR) ≥70%, Thrombolysis in Myocardial Infarction (TIMI) flow grade, and myocardial blush grade (MBG). Major adverse cardiac events (MACEs) were also assessed at 6 months. Safety outcome included incidence of acute kidney injury (AKI) postprimary PCI. Sixty patients completed the study. At 6 months, there was no significant decrease in the incidence of LV remodeling with RIPostC group ( p  = 0.42). Similarly, RIPostC failed to show significant improvement in LVEF. However, STR ≥ 70% after primary PCI was achieved more in the RIPostC group ( p  = 0.04), with a trend toward less AKI in the RIPostC group ( p  = 0.08). All other secondary end points, including MACEs at 6 months, were similar in both groups. RIPostC might be associated with better STR after reperfusion as well as less incidence of AKI in patients undergoing primary PCI for anterior wall STEMI, indicating potential benefit in those patients. Whether this role can be translated to better outcomes after primary PCI warrants further investigation.

Remote Ischemic Conditioning and Renal Protection

Over the course of the last 2 decades, the concept of remote ischemic conditioning (RIC) has attracted considerable research interest, because RIC, in most of its embodiments offers an inexpensive way of protecting tissues against ischemic damage inflicted by a number of medical conditions or procedures. Acute kidney injury (AKI) is a common side effect in the context of various medical procedures, and RIC has been suggested as a means of reducing its incidence. Outcomes regarding kidney function have been reported in numerous studies that evaluated the effects of RIC in a variety of settings (eg, cardiac surgery, interventions requiring intravenous administration of contrast media). Although several individual studies have implied a beneficial effect of RIC in preserving kidney function, 3 recently published randomized controlled trials evaluating more than 1000 patients each (Effect of Remote Ischemic Preconditioning in the Cardiac Surgery, Remote Ischaemic Preconditioning for Heart Surgery, and ERICCA) were negative. However, AKI or any other index of renal function was not a stand-alone primary end point in any of these trials. On the other hand, a range of meta-analyses (each including thousands of participants) have reported mixed results, with the most recent among them showing benefit from RIC, pinpointing at the same time a number of shortcomings in published studies, adversely affecting the quality of available data. The present review provides a critical appraisal of the current state of this field of research. It is the opinion of the authors of this review that there is a clear need for a common clinical trial framework for ischemic conditioning studies. If the current babel of definitions, procedures, outcomes, and goals persists, it is most likely that soon ischemic conditioning will be "yesterday's news" with no definitive conclusions having been reached in terms of its real clinical utility.

Ischaemic preconditioning for the reduction of renal ischaemia reperfusion injury

BACKGROUND

Ischaemia reperfusion injury can lead to kidney dysfunction or failure. Ischaemic preconditioning is a short period of deprivation of blood supply to particular organs or tissue, followed by a period of reperfusion. It has the potential to protect kidneys from ischaemia reperfusion injury.

OBJECTIVES

This review aimed to look at the benefits and harms of local and remote ischaemic preconditioning to reduce ischaemia and reperfusion injury among people with renal ischaemia reperfusion injury.

SEARCH METHODS

We searched Cochrane Kidney and Transplant's Specialised Register to 5 August 2016 through contact with the Information Specialist using search terms relevant to this review.

SELECTION CRITERIA

We included all randomised controlled trials measuring kidney function and the role of ischaemic preconditioning in patients undergoing a surgical intervention that induces kidney injury. Kidney transplantation studies were excluded.

DATA COLLECTION AND ANALYSIS

Studies were assessed for eligibility and quality; data were extracted by two independent authors. We collected basic study characteristics: type of surgery, remote ischaemic preconditioning protocol, type of anaesthesia. We collected primary outcome measurements: serum creatinine and adverse effects to remote ischaemic preconditioning and secondary outcome measurements: acute kidney injury, need for dialysis, neutrophil gelatinase-associated lipocalin, hospital stay and mortality. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes.

MAIN RESULTS

We included 28 studies which randomised a total of 6851 patients. Risk of bias assessment indicated unclear to low risk of bias for most studies. For consistency regarding the direction of effects, continuous outcomes with negative values, and dichotomous outcomes with values less than one favour remote ischaemic preconditioning. Based on high quality evidence, remote ischaemic preconditioning made little or no difference to the reduction of serum creatinine levels at postoperative days one (14 studies, 1022 participants: MD -0.02 mg/dL, 95% CI -0.05 to 0.02; I2 = 21%), two (9 studies, 770 participants: MD -0.04 mg/dL, 95% CI -0.09 to 0.02; I2 = 31%), and three (6 studies, 417 participants: MD -0.05 mg/dL, 95% CI -0.19 to 0.10; I2 = 68%) compared to control.Serious adverse events occurred in four patients receiving remote ischaemic preconditioning by iliac clamping. It is uncertain whether remote ischaemic preconditioning by cuff inflation leads to increased adverse effects compared to control because the certainty of the evidence is low (15 studies, 3993 participants: RR 3.47, 95% CI 0.55 to 21.76; I2 = 0%); only two of 15 studies reported any adverse effects (6/1999 in the remote ischaemic preconditioning group and 1/1994 in the control group), the remaining 13 studies stated no adverse effects were observed in either group.Compared to control, remote ischaemic preconditioning made little or no difference to the need for dialysis (13 studies, 2417 participants: RR 0.85, 95% CI 0.37 to 1.94; I2 = 60%; moderate quality evidence), length of hospital stay (8 studies, 920 participants: MD 0.17 days, 95% CI -0.46 to 0.80; I2 = 49%, high quality evidence), or all-cause mortality (24 studies, 4931 participants: RR 0.86, 95% CI 0.54 to 1.37; I2 = 0%, high quality evidence).Remote ischaemic preconditioning may have slightly improved the incidence of acute kidney injury using either the AKIN (8 studies, 2364 participants: RR 0.76, 95% CI 0.57 to 1.00; I2 = 61%, high quality evidence) or RIFLE criteria (3 studies, 1586 participants: RR 0.91, 95% CI 0.75 to 1.12; I2 = 0%, moderate quality evidence).

AUTHORS' CONCLUSIONS

Remote ischaemic preconditioning by cuff inflation appears to be a safe method, and probably leads to little or no difference in serum creatinine, adverse effects, need for dialysis, length of hospital stay, death and in the incidence of acute kidney injury. Overall we had moderate-high certainty evidence however the available data does not confirm the efficacy of remote ischaemic preconditioning in reducing renal ischaemia reperfusion injury in patients undergoing major cardiac and vascular surgery in which renal ischaemia reperfusion injury may occur.

Limited Clinical Utility of Remote Ischemic Conditioning in Renal Transplantation: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

We conducted this meta-analysis of randomized controlled trials (RCTs) to investigate whether remote ischemic conditioning (RIC) could improve graft functions in kidney transplantation.

METHODS

PubMed, Web of Science, and Cochrane Library were comprehensively searched to identify all eligible studies by October 5, 2016. The treatment effects were examined with risk ratio (RR) and weighted mean difference with the corresponding 95% confidence intervals (CI). The statistical significance and heterogeneity were assessed with both Z-test and Q-test.

RESULTS

A total of six RCTs including 651 recipients, were eventually identified. Compared to the controls, RIC could reduce the incidence of delayed graft function (DGF) after kidney transplantation (random-effects model: RR = 0.89; fixed-effect model: RR = 0.84). However, the decrease did not reveal statistical significance. The subgroup analysis by RIC type demonstrated no significant difference among the three interventions in protecting renal allografts against DGF. Furthermore, no significant difference could be observed in the incidence of acute rejection, graft loss, 50% fall in serum creatinine, as well as the estimated glomerular filtration rate and hospital stay between the RIC and Control groups.

CONCLUSIONS

This meta-analysis suggested that RIC might exert renoprotective functions in human kidney transplantation, and further well-designed RCTs with large sample size are warranted to assess its clinical efficacy.

Remote limb ischemic post-conditioning attenuates ischemia-reperfusion injury in rat skin flapby limiting oxidative stress

PURPOSE

To investigate the effect of remote ischemic post-conditioning (RIPoC) against ischemia-reperfusion (I/R) injury on flaps of rats.

METHODS

Sprague-Dawley rats were randomized into the Sham, Control, RIPoC1 and RIPoC2 groups. All the animals were submitted to a 5×4 cm superficial inferior epigastric artery flap. Eight hours of flap ischemia was induced and two protocols of limb RIPoC were applied. Tissue MDA level and SOD activity in 24-h reperfusion were assessed. Flap survival was assessed 7 days postoperatively.

RESULTS

Compared to the Control group, the RIPoC1 group showed statistically decreased MDA level at 6-, 12-, and 24-h reperfusion (P = 0.01, P < 0.01 and P < 0.01, respectively), and statistically increased SOD activity at 12- and 24-h reperfusion (P < 0.05 and P < 0.01, respectively). Flap survival rate on the 7th day was significantly higher in the RIPoC1 group than the control group (47.9 ± 6.4 vs . 29.4 ± 7.1 %, P < 0.01).

CONCLUSION

Three cycles of 5-min Limb remote ischemic post-conditioning rather than a single cycle of 15-min limb RIPoC has protective effect on flaps against ischemia-reperfusion injury by attenuating oxidative stress.

Cardioprotection by remote ischemic conditioning: Mechanisms and clinical evidences

In remote ischemic conditioning (RIC), several cycles of ischemia and reperfusion render distant organ and tissues more resistant to the ischemia-reperfusion injury. The intermittent ischemia can be applied before the ischemic insult in the target site (remote ischemic preconditioning), during the ischemic insult (remote ischemic perconditioning) or at the onset of reperfusion (remote ischemic postconditioning). The mechanisms of RIC have not been completely defined yet; however, these mechanisms must be represented by the release of humoral mediators and/or the activation of a neural reflex. RIC has been discovered in the heart, and has been arising great enthusiasm in the cardiovascular field. Its efficacy has been evaluated in many clinical trials, which provided controversial results. Our incomplete comprehension of the mechanisms underlying the RIC could be impairing the design of clinical trials and the interpretation of their results. In the present review we summarize current knowledge about RIC pathophysiology and the data about its cardioprotective efficacy.

Remote Ischemic Conditioning for Preventing Contrast-Induced Acute Kidney Injury in Patients Undergoing Percutaneous Coronary Interventions/Coronary Angiography: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

It is uncertain whether remote ischemic conditioning (RIC) has a protective effect on contrast-induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI)/coronary artery angiography (CAG). We performed a meta-analysis of randomized controlled trials (RCTs) to assess the effect of RIC on CI-AKI in such patients.

METHODS

PubMed, MEDLINE, EMBASE, ClinicalTrials.gov, and the Cochrane Central Register of Controlled Trials databases were searched for RCTs that assessed the effect of RIC on CI-AKI in patients undergoing PCI/CAG.

RESULTS

Ten RCTs with 1389 patients (RIC group, 757 and control, 632) were included. The RIC group significantly exerted a lower risk of CI-AKI compared to the controls (odds ratio [OR] = 0.52, 95% confidence interval [CI] = 0.34-0.77, P = .001), and they had the similar effect on major adverse cardiovascular events within 1 year (OR = 0.36, 95% CI = 0.20-0.66, P < .001). The RIC reduced the rates of death within 30 days, but this was not significant (OR = 0.16, 95% CI = 0.02-1.34, P = .091). The RIC was associated with a significantly lower incidence of CI-AKI in patients following elective PCI/CAG (OR = 0.54, 95% CI = 0.33-0.87, P = .011). The RIC before not after the intervention was effective in reducing the occurrence of CI-AKI (OR: 0.37 vs 1.05, P = .022). The RIC of the upper arm has statistically significant effect on protecting CI-AKI but not that of the lower limb (OR: 0.41 vs 1.41, P = .004). The effect of RIC on CI-AKI was similar between patients with a mean estimated glomerular filtration rate <60 mL/min/1.73 m(2) and those with mean rates ≥60 (OR: 0.23 vs 0.41, P = .333).

CONCLUSION

The RIC reduced the incidence of CI-AKI in those receiving PCI/CAG. And RIC of the upper arm significantly reduced the risk of CI-AKI but not RIC of the lower limb in patients undergoing PCI/CAG.

Remote ischemic post-conditioning improves neurological function by AQP4 down-regulation in astrocytes

Cerebral ischemia is a primary cause of human death and long-term disability. Previous studies have suggested that remote ischemic post-conditioning (RIPC) is a potential useful tool for cerebral ischemic treatment. However, the protective mechanism of RIPC is not very clear. This study verified the hypothesis that, in remote post-conditioning of cerebral ischemic rats, down-regulation of aquaporin 4 (AQP4), which is an important player for water hemostasis in astrocytes, could attenuate cerebral damage after transient middle cerebral artery occlusion (MCAO). In this study, RIPC model was established after MCAO. Each hind limb of rat was clamped by small rubber tubes for 10 min, and then the tubes were opened for 10 min. The clamping and opening were operated for a total of three cycles to block the hind limbs blood flow. The results showed that, RIPC could significantly improve neurological function, decrease the percentage of the infarct volume and edema, and elevate the integrity of blood-brain barrier (BBB). In addition, the numbers of AQP4 and glial fibrillary acidic protein (GFAP) positive cells were significantly lower in the RIPC group. Moreover, we found that AQP4 expression decreased in response to ischemia/reperfusion in the RIPC group. Our findings indicated that RIPC could attenuate focal cerebral ischemia/reperfusion injury, and the neuroprotective mechanism was related with the down-regulation of AQP4 in astrocytes.

Using remote ischemic conditioning to reduce acute kidney injury in patients undergoing percutaneous coronary intervention: a meta-analysis

BACKGROUND AND AIMS

It remains uncertain whether remote ischemic conditioning (RIC) could prevent acute kidney injury (AKI) in patients undergoing percutaneous coronary intervention (PCI). Thus, this meta-analysis aiming to explore the renoprotective role of RIC in patients undergoing PCI was carried out.

METHODS

PubMed, Web of Science, and Cochrane Library were searched from inception to 31 December 2014 to identify eligible randomized controlled trials. Pooled risk ratio, mean, standard deviation and 95% CI were used to assess the effect by fixed- or random-effect models. Heterogeneity was assessed by the Cochran Q and I( 2) statistics.

RESULTS

Nine trials were included in this study. RIC decreased the AKI incidence in patients undergoing PCI compared with control individuals (P < 0.001; RR, 0.53; 95% CI, 0.39-0.71; P for heterogeneity = 0.15; heterogeneity χ(2 )= 13.38; I(2 )= 33%). Besides, limb conditioning attenuated AKI (P = 0.001; RR, 0.57; 95% CI, 0.41-0.81; P for heterogeneity = 0.13; heterogeneity χ(2 )= 12.48; I(2 )= 36%). Remote postconditioning may reduce the AKI incidence (P = 0.03; RR, 0.65; 95% CI, 0.44-0.97; P for heterogeneity = 0.15; heterogeneity χ(2 )= 5.36; I(2 )= 44%); remote preconditioning could also play a renoprotective role (P < 0.001; RR, 0.42; 95% CI, 0.27-0.65; P for heterogeneity = 0.31; heterogeneity χ(2 )= 5.98; I(2 )= 16%).

CONCLUSIONS

RIC may not only confer cardioprotection, but also reduce the incidence of AKI in patients undergoing PCI, ultimately leading to better clinical outcomes. RIC may potentially be a powerful approach conferring protection in patients undergoing PCI in future clinical practice. More large-scale trials are required to obtain a more reliable conclusion.

Remote ischemic conditioning: from experimental observation to clinical application: report from the 8th Biennial Hatter Cardiovascular Institute Workshop

In 1993, Przyklenk and colleagues made the intriguing experimental observation that ‘brief ischemia in one vascular bed also protects remote, virgin myocardium from subsequent sustained coronary artery occlusion’ and that this effect ‘…. may be mediated by factor(s) activated, produced, or transported throughout the heart during brief ischemia/reperfusion’. This seminal study laid the foundation for the discovery of ‘remote ischemic conditioning’ (RIC), a phenomenon in which the heart is protected from the detrimental effects of acute ischemia/reperfusion injury (IRI), by applying cycles of brief ischemia and reperfusion to an organ or tissue remote from the heart. The concept of RIC quickly evolved to extend beyond the heart, encompassing inter-organ protection against acute IRI. The crucial discovery that the protective RIC stimulus could be applied non-invasively, by simply inflating and deflating a blood pressure cuff placed on the upper arm to induce cycles of brief ischemia and reperfusion, has facilitated the translation of RIC into the clinical setting. Despite intensive investigation over the last 20 years, the underlying mechanisms continue to elude researchers. In the 8th Biennial Hatter Cardiovascular Institute Workshop, recent developments in the field of RIC were discussed with a focus on new insights into the underlying mechanisms, the diversity of non-cardiac protection, new clinical applications, and large outcome studies. The scientific advances made in this field of research highlight the journey that RIC has made from being an intriguing experimental observation to a clinical application with patient benefit.