The Role of RIPC in Preventing Organ Damage, Inflammation, and Oxidative Stress during Lower Limb DSA: A Randomised Controlled Trial

Remote ischaemic preconditioning for transcatheter aortic valve replacement: a protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become an important treatment in patients with aortic valve disease with the continuous advancement of technology and the improvement of outcomes. However, TAVR-related complications still increase patient morbidity and mortality. Remote ischaemic preconditioning (RIPC) is a simple procedure that provides perioperative protection for many vital organs. However, the efficiency of RIPC on TAVR remains unclear based on inconsistent conclusions from different clinical studies. Therefore, we will perform a protocol for a systematic review and meta-analysis to identify the efficiency of RIPC on TAVR.

METHODS AND ANALYSIS

English databases (PubMed, Web of Science, Ovid Medline, Embase and Cochrane Library), Chinese electronic databases (Wanfang Database, VIP Database and China National Knowledge Infrastructure) and trial registry databases will be searched from inception to December 2023 to identify randomised controlled trials of RIPC on TAVR. We will calculate mean differences or standardised mean differences with 95% CIs for continuous data, and the risk ratio (RR) with 95% CIs for dichotomous data by Review Manager version 5.4. Fixed-effects model or random-effects model will be used according to the degree of statistical heterogeneity assessed by the I-square test. We will evaluate the risk of bias using the Cochrane risk-of-bias tool 2 and assess the evidence quality of each outcome by the Grading of Recommendations Assessment, Development and Evaluation. The robustness of outcomes will be evaluated by trial sequential analysis. In addition, we will evaluate the publication bias of outcomes by Funnel plots and Egger's regression test.

ETHICS AND DISSEMINATION

Ethical approval was not required for this systematic review protocol. The results will be disseminated through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42023462926.

Improvement of restless leg syndrome in maintenance hemodialysis patients with limb ischemic preconditioning: a single-center randomized controlled clinical trial

OBJECTIVE

This study evaluated the efficacy and safety of limb ischemic preconditioning (LIPC) in treating restless leg syndrome (RLS) in maintenance hemodialysis (MHD) patients.

METHODS

A total number of 45 patients participated in the study. They were randomly divided into LIPC group and control group. The LIPC was performed by inflating the limb ischemic preconditioning training device in the patient's thigh to 200 mmHg to create transient ischemia, whereas control group inflated the device to 20 mmHg. International Restless Legs Syndrome (IRLS), Clinical Global Impression Scale (CGI-S), and Medical Outputs Study Sleep Scale were employed to evaluate LIPC effectiveness. The primary endpoint was the 'rate of clinical improvement in RLS severity', defined as the percentage of patients who had an IRLS score decrease of ≥5 points in each group.

RESULTS

After intervention, the rate of clinical improvement in RLS severity was 56.5% in the LIPC group and 13.6% in the control group (13 (56.5) vs 3 (13.6), p = 0.003). In addition, the LIPC group's IRLS, CGI-S scores, the sleep disturbance and somnolence scores showed a significant downward trend compared to the control group (-5.5 ± 5.3 vs - 1.0 ± 3.8, p = 0.002; -1.7 ± 1.2 vs - 0.5 ± 1.4, p = 0.003; -15.5 ± 17.8 vs 3.7 ± 12.0, p < 0.001; -9.9 ± 18.8 vs - 2.4 ± 8.6, p = 0.003). During the study, there were no serious adverse event in any of the patients.

CONCLUSIONS

LIPC could be employed to effectively and safely alleviate the RLS symptoms in MHD patients.

Effects of RIPC on the Metabolomical Profile during Lower Limb Digital Subtraction Angiography: A Randomized Controlled Trial

Remote ischemic preconditioning (RIPC) has demonstrated protective effects in patients with lower extremity arterial disease (LEAD) undergoing digital subtraction angiography (DSA) and/or percutaneous transluminal angioplasty (PTA). This study aimed to investigate the impact of RIPC on the metabolomical profile of LEAD patients undergoing these procedures and to elucidate its potential underlying mechanisms. A total of 100 LEAD patients were enrolled and randomly assigned to either the RIPC group (n = 46) or the sham group (n = 54). Blood samples were drawn before and 24 h after intervention. Targeted metabolomics analysis was performed using the AbsoluteIDQ p180 Kit, and changes in metabolite concentrations were compared between the groups. The RIPC group demonstrated significantly different dynamics in nine metabolites compared to the sham group, which generally showed a decrease in metabolite concentrations. The impacted metabolites included glutamate, taurine, the arginine-dimethyl-amide-to-arginine ratio, lysoPC a C24:0, lysoPC a C28:0, lysoPC a C26:1, PC aa C38:1, PC ae C30:2, and PC ae C44:3. RIPC exhibited a 'stabilization' effect, maintaining metabolite levels amidst ischemia-reperfusion injuries, suggesting its role in enhancing metabolic control. This may improve outcomes for LEAD patients. However, additional studies are needed to definitively establish causal relationships among these metabolic changes.

Exosomal HSP90 induced by remote ischemic preconditioning alleviates myocardial ischemia/reperfusion injury by inhibiting complement activation and inflammation

BACKGROUND/AIMS

The activation of the complement system and subsequent inflammatory responses are important features of myocardial ischemia/reperfusion (I/R) injury. Exosomes are nanoscale extracellular vesicles that play a significant role in remote ischemic preconditioning (RIPC) cardioprotection. The present study aimed to test whether RIPC-induced plasma exosomes (RIPC-Exo) exert protective effects on myocardial I/R injury by inhibiting complement activation and inflammation and whether exosomal heat shock protein 90 (HSP90) mediates these effects.

METHODS

Rat hearts underwent 30 min of coronary ligation followed by 2 h of reperfusion. Plasma exosomes were isolated from RIPC rats and injected into the infarcted myocardium immediately after ligation. Sixty rats were randomly divided into Sham, I/R, I/R + RIPC-Exo (50 µg/µl), and RIPC-Exo + GA (geldanamycin, 1 mg/kg, administration 30 min before ligation) groups. Cardiomyocyte apoptosis, the release of myocardial markers (LDH, cTnI and CK-MB), infarct size, the expression of HSP90, complement component (C)3, C5a, c-Jun N-terminal kinase (JNK), interleukin (IL)-1β, tumor necrosis factor (TNF)-alpha and intercellular adhesion molecule -1 (ICAM-1) were assessed.

RESULTS

RIPC-Exo treatment significantly reduced I/R-induced cardiomyocyte apoptosis, the release of myocardial markers (LDH, cTnI and CK-MB) and infarct size. These beneficial effects were accompanied by decreased C3 and C5a expression, decreased inflammatory factor levels (IL-1β, TNF-α, and ICAM-1), decreased JNK and Bax, and increased Bcl-2 expression. Meanwhile, the expression of HSP90 in the exosomes from rat plasma increased significantly after RIPC. However, treatment with HSP90 inhibitor GA significantly reversed the cardioprotection of RIPC-Exo, as well as activated complement component, JNK signalling and inflammation, indicating that HSP90 in exosomes isolated from the RIPC was important in mediating the cardioprotective effects during I/R.

CONCLUSION

Exosomal HSP90 induced by RIPC played a significant role in cardioprotection against I/R injury, and its function was in part linked to the inhibition of the complement system, JNK signalling and local and systemic inflammation, ultimately alleviating I/R-induced myocardial injury and apoptosis by the upregulation of Bcl-2 expression and the downregulation of proapoptotic Bax.

Remote ischaemic preconditioning versus no remote ischaemic preconditioning for vascular and endovascular surgical procedures

BACKGROUND

Despite advances in perioperative care, elective major vascular surgical procedures still carry a significant risk of morbidity and mortality. Remote ischaemic preconditioning (RIPC) is the temporary blocking of blood flow to vascular beds remote from those targeted by surgery. It has the potential to provide local tissue protection from further prolonged periods of ischaemia. However, the efficacy and safety of RIPC in people undergoing major vascular surgery remain unknown. This is an update of a review published in 2011.  OBJECTIVES: To assess the benefits and harms of RIPC versus no RIPC in people undergoing elective major vascular and endovascular surgery.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov to 1 April 2022.

SELECTION CRITERIA

We included all randomised controlled trials that evaluated the role of RIPC in reducing perioperative mortality and morbidities in people undergoing elective major vascular or endovascular surgery.

DATA COLLECTION AND ANALYSIS

We collected data on the characteristics of the trial, methodological quality, and the remote ischaemic preconditioning stimulus used. Our primary outcome was perioperative mortality, and secondary outcomes included myocardial infarction, renal impairment, stroke, hospital stay, limb loss, and operating time or total anaesthetic time. We analysed the data using random-effects models. For each outcome, we calculated the risk ratio (RR) or mean difference (MD) with a 95% confidence interval (CI) based on an intention-to-treat analysis. In addition, we used GRADE to assess the certainty of the evidence for each outcome.

MAIN RESULTS

We included 14 trials which randomised a total of 1295 participants (age range: 64.5 to 76 years; 84% male; study periods ranged from 2003 to 2019). In general, the included studies were at low to unclear risk of bias for most risk of bias domains. The certainty of evidence of main outcomes was moderate due to imprecision of results, moderate heterogeneity, or possible publication bias. We found that RIPC made no clear difference in perioperative mortality compared with no RIPC (RR 1.41, 95% CI 0.59 to 3.40; I2 = 0%; 10 studies, 965 participants; moderate-certainty evidence). Similarly, we found no clear difference between the two groups for myocardial infarction (RR 0.82, 95% CI 0.49 to 1.40; I2 = 7%; 11 studies, 1001 participants; moderate-certainty evidence), renal impairment (RR 1.07, 95% CI 0.62 to 1.86; I2 = 40%; 12 studies, 1054 participants; moderate-certainty evidence), stroke (RR 0.33, 95% CI 0.04 to 3.15; I2 = 0%; 4 studies, 392 participants; moderate-certainty evidence), limb loss (RR 0.74, 95% CI 0.05 to 10.61; I2 = 32%; 3 studies, 322 participants; low-certainty evidence), hospital stay (MD -0.94 day, 95% CI -1.95 to 0.07; I2 = 17%; 7 studies, 569 participants; moderate-certainty evidence), and operating time or total anaesthetic time (MD 5.76 minutes, 95% CI -3.25 to 14.76; I2 = 44%; 10 studies, 803 participants; moderate-certainty evidence).  AUTHORS' CONCLUSIONS: Overall, compared with no RIPC, RIPC probably leads to little or no difference in perioperative mortality, myocardial infarction, renal impairment, stroke, hospital stay, and operating time, and may lead to little or no difference in limb loss in people undergoing elective major vascular and endovascular surgery. Adequately powered and designed randomised studies are needed, focusing in particular on the clinical endpoints and patient-centred outcomes.