The effect of repeated remote ischemic postconditioning after an ischemic stroke (REPOST): A randomized controlled trial

Remote ischemic conditioning after stroke: Research progress in clinical study

BACKGROUND AND PURPOSE

Stroke is a leading cause of global morbidity and mortality, indicating the necessity and urgency of effective prevention and treatment. Remote ischemic conditioning (RIC) is a convenient, simple, non-intrusive, and effective method that can be easily added to the treatment regime of stroke patients. Animal experiments and clinical trials have proved the neuroprotective effects of RIC on brain injury including (examples of neuroprotective effects). This neuroprotection is achieved by raising brain tolerance to ischemia, increasing local cerebral blood perfusion, promoting collateral circulations, neural regeneration, and reducing the incidence of hematomas in brain tissue. This current paper will summarize the studies within the last 2 years for the comprehensive understanding of the use of RIC in the treatment of stroke.

METHODS

This paper summarizes the clinical research progress of RIC on stroke (ischemic stroke and hemorrhagic stroke (HS)). This paper is a systematic review of research published on registered clinical trials using RIC in stroke from inception through November 2022. Four major databases (PUBMED, WEB OF SCIENCE, EMBASE, and ClinicalTrials.gov) were searched.

RESULTS

Forty-eight studies were identified meeting our criteria. Of these studies, 14 were in patients with acute ischemic stroke with onset times ranging from 6 h to 14 days, seven were in patients with intravenous thrombolysis or endovascular thrombectomy, 10 were in patients with intracranial atherosclerotic stenosis, six on patients with vascular cognitive impairment, three on patients with moyamoya disease, and eight on patients with HS. Of the 48 studies, 42 were completed and six are ongoing.

CONCLUSIONS

RIC is safe, feasible, and effective in the treatment of stroke. Large-scale research is still required to explore the optimal treatment options and mechanisms of RIC in the future to develop a breakthrough in stroke prevention and treatment.

New Perspectives in Neuroprotection for Ischemic Stroke

The constant failure of new neuroprotective therapies for ischemic stroke has partially halted the search for new therapies in recent years, mainly because of the high investment risk required to develop a new treatment for a complex pathology, such as stroke, with a narrow intervention window and associated comorbidities. However, owing to recent progress in understanding the stroke pathophysiology, improvement in patient care in stroke units, development of new imaging techniques, search for new biomarkers for early diagnosis, and increasingly widespread use of mechanical recanalization therapies, new opportunities have opened for the study of neuroprotection. This review summarizes the main protective agents currently in use, some of which are already in the clinical evaluation phase. It also includes an analysis of how recanalization therapies, new imaging techniques, and biomarkers have improved their efficacy.

Chinese Stroke Association guidelines for clinical management of ischaemic cerebrovascular diseases: executive summary and 2023 update

BACKGROUND

China is one of the countries with the highest burden of stroke. Implementing multidimensional management guidelines will help clinicians practise evidence-based care, improve patient outcomes and alleviate societal burdens. This update of the 2019 edition will provide the latest comprehensive recommendations for the diagnosis and treatment of ischaemic cerebrovascular diseases.

METHODS

We conducted a comprehensive search on MEDLINE (via PubMed) up to 31 August 2023. The writing team established the recommendations through multiple rounds of online and offline discussions. Each recommendation was graded using the evidence grading algorithm developed by the Chinese Stroke Association (CSA). The draft was reviewed and finalised by the CSA Stroke Guidelines Writing Committee.

RESULTS

This update included revisions of 15 existing recommendations and 136 new recommendations in the following areas of stroke care: emergency assessment and diagnosis of ischaemic cerebrovascular disease, acute-phase reperfusion therapy, evaluation of underlying mechanisms, antithrombotic therapy, prevention and treatment of complications, and risk factor management.

CONCLUSIONS

This guideline updated the recommendations for the clinical management of ischaemic cerebrovascular disease from 2019.

Remote Ischemic Conditioning for Acute Stroke: The RESIST Randomized Clinical Trial

Importance

Despite some promising preclinical and clinical data, it remains uncertain whether remote ischemic conditioning (RIC) with transient cycles of limb ischemia and reperfusion is an effective treatment for acute stroke.

Objective

To evaluate the effect of RIC when initiated in the prehospital setting and continued in the hospital on functional outcome in patients with acute stroke.

Design, Setting, and Participants

This was a randomized clinical trial conducted at 4 stroke centers in Denmark that included 1500 patients with prehospital stroke symptoms for less than 4 hours (enrolled March 16, 2018, to November 11, 2022; final follow-up, February 3, 2023).

Intervention

The intervention was delivered using an inflatable cuff on 1 upper extremity (RIC cuff pressure, ≤200 mm Hg [n = 749] and sham cuff pressure, 20 mm Hg [n = 751]). Each treatment application consisted of 5 cycles of 5 minutes of cuff inflation followed by 5 minutes of cuff deflation. Treatment was started in the ambulance and repeated at least once in the hospital and then twice daily for 7 days among a subset of participants.

Main Outcomes and Measures

The primary end point was improvement in functional outcome measured as a shift across the modified Rankin Scale (mRS) score (range, 0 [no symptoms] to 6 [death]) at 90 days in the target population with a final diagnosis of ischemic or hemorrhagic stroke.

Results

Among 1500 patients who were randomized (median age, 71 years; 591 women [41%]), 1433 (96%) completed the trial. Of these, 149 patients (10%) were diagnosed with transient ischemic attack and 382 (27%) with a stroke mimic. In the remaining 902 patients with a target diagnosis of stroke (737 [82%] with ischemic stroke and 165 [18%] with intracerebral hemorrhage), 436 underwent RIC and 466 sham treatment. The median mRS score at 90 days was 2 (IQR, 1-3) in the RIC group and 1 (IQR, 1-3) in the sham group. RIC treatment was not significantly associated with improved functional outcome at 90 days (odds ratio [OR], 0.95; 95% CI, 0.75 to 1.20, P = .67; absolute difference in median mRS score, -1; -1.7 to -0.25). In all randomized patients, there were no significant differences in the number of serious adverse events: 169 patients (23.7%) in the RIC group with 1 or more serious adverse events vs 175 patients (24.3%) in the sham group (OR, 0.97; 95% CI, 0.85 to 1.11; P = .68). Upper extremity pain during treatment and/or skin petechia occurred in 54 (7.2%) in the RIC group and 11 (1.5%) in the sham group.

Conclusions and Relevance

RIC initiated in the prehospital setting and continued in the hospital did not significantly improve functional outcome at 90 days in patients with acute stroke.

Trial Registration

ClinicalTrials.gov Identifier: NCT03481777.

Efficacy and safety of remote ischemic conditioning for acute ischemic stroke: A comprehensive meta-analysis from randomized controlled trials

BACKGROUND AND PURPOSE

Remote ischemic conditioning (RIC) is a remote, transient, and noninvasive procedure providing temporary ischemia and reperfusion. However, there is no comprehensive literature investigating the efficacy and safety of RIC for the treatment of acute ischemic stroke. In the present study, we performed a comprehensive meta-analysis of the available studies.

METHODS

MEDLINE, Embase, the Cochrane Library database (CENTRAL), and ClinicalTrials.gov were searched before Sep 7, 2022. The data were analyzed using Review Manager 5.4.1 software, Stata version 16.0 software, and R 4.2.0 software. Odds ratio (OR), mean difference (MD), and corresponding 95% CIs were pooled using fixed-effects meta-analysis.

RESULTS

We pooled 6392 patients from 17 randomized controlled trials. Chronic RIC could reduce the recurrence of ischemic stroke at the endpoints (OR 0.67, 95% CI [0.51, 0.87]). RIC could also improve the prognosis of patients at 90 days as assessed by mRS score (mRS 0-1: OR 1.29, 95% CI [1.09, 1.52]; mRS 0-2: OR 1.22, 95% CI [1.01, 1.48]) and at the endpoints assessed by NIHSS score (MD -0.99, 95% CI [-1.45, -0.53]). RIC would not cause additional adverse events such as death (p = 0.72), intracerebral hemorrhage events (p = 0.69), pneumonia (p = 0.75), and TIA (p = 0.24) but would inevitably cause RIC-related adverse events (OR 26.79, 95% CI [12.08, 59.38]).

CONCLUSIONS

RIC could reduce the stroke recurrence and improve patients' prognosis. Intervention on bilateral upper limbs, 5 cycles, and a length of 50 min in each intervention might be an optimal protocol for RIC at present. RIC could be an effective therapy for patients not eligible for reperfusion therapy. RIC would not cause other adverse events except for relatively benign RIC-related adverse events.

Safety and efficacy of remote ischemic conditioning combined with endovascular thrombectomy for acute ischemic stroke due to large vessel occlusion of anterior circulation: A multicenter, randomized, parallel-controlled clinical trial (SERIC-EVT): Study protocol

RATIONALE/AIM

Many patients undergoing successful recanalization after endovascular thrombectomy (EVT) do not have a good outcome; additional neuroprotection might benefit this group. Remote ischemic conditioning (RIC) stimulates endogenous protective mechanisms and may have a neuroprotective in acute brain ischemia. The safety and efficacy of RIC combined with endovascular thrombectomy (SERIC-EVT) trial is investigating the safety and efficacy of RIC for patients with acute ischemic stroke (AIS) who underwent EVT due to large vessel occlusion of the anterior circulation.

METHODS

SERIC-EVT is a multicenter, randomized, parallel-controlled, and blinded endpoint clinical trial. Patients are recruited from 10 hospitals in Jilin Province, Northeast China. Patients with anterior circulation AIS undergoing EVT due to large vessel occlusion are randomized in a 1:1 ratio to RIC or sham-RIC. Participants will receive standard medical treatment and an inflation pressure of 200 mmHg (RIC group) or 60 mmHg (sham-RIC group) twice daily for seven consecutive days.

STUDY OUTCOMES

The primary outcome is the proportion of patients with modified Rankin Scale (mRS) score of 0-2 on day 90. Secondary outcome measures include the National Institute of Health Stroke Scale, Barthel Index, and mRS scores obtained at 24 h, 7 days, 30 ± 3 days, and 90 ± 3 days post-EVT, recanalization rate, expanded Thrombolysis in Cerebral Infarction score, and symptomatic intracranial hemorrhage post-EVT. Mortality and all adverse events, including skin changes and pain scores, within the first 90 days will be used as safety outcome measures.

SAMPLE SIZE ESTIMATES

Based on previous studies, we estimate a 14% difference in functional independence (the mRS ⩽2) between RIC and sham-RIC groups. Considering a significance level of 5% and power of 80%, and one-fifth of patients lost to follow up, the planned sample size is 498 patients (249 per group).

DISCUSSION

RIC might be a strategy that improves 3-month clinical outcomes in AIS patients who have undergone EVT due to large vessel occlusion of anterior circulation. SERIC-EVT will determine whether this is the case.

A review of remote ischemic conditioning as a potential strategy for neural repair poststroke

Ischemic stroke is one of the major disabling health-care problem and multiple different approaches are needed to enhance rehabilitation, in which neural repair is the structural basement. Remote ischemic conditioning (RIC) is a strategy to trigger endogenous protect. RIC has been reported to play neuroprotective role in acute stage of stroke, but the effect of RIC on repair process remaining unclear. Several studies have discovered some overlapped mechanisms RIC and neural repair performs. This review provides a hypothesis that RIC is a potential therapeutic strategy on stroke rehabilitation by evaluating the existing evidence and puts forward some remaining questions to clarify and future researches to be performed in the field.

Remote ischemic conditioning for acute ischemic stroke part 2: Study protocol for a randomized controlled trial

Background

Remote ischemic conditioning (RIC) refers to the application of repeated short periods of ischemia intended to protect remote areas against tissue damage during and after prolonged ischemia.

Aim

We aim to evaluate the efficacy of RIC, determined by the modified Rankin Scale (mRS) score at 90 days after stroke onset.

Design and methods

This study is an investigator-initiated, multicenter, prospective, randomized, open-label, parallel-group clinical trial. The sample size is 400, comprising 200 patients who will receive RIC and 200 controls. The patients will be divided into three groups according to their National Institutes of Health Stroke Scale score at enrollment: 5–9, mild; 10–14, moderate; 15–20, severe. The RIC protocol will be comprised of four cycles, each consisting of 5 min of blood pressure cuff inflation (at 200 mmHg or 50 mmHg above the systolic blood pressure) followed by 5 min of reperfusion, with the cuff placed on the thigh on the unaffected side. The control group will only undergo blood pressure measurements before and after the intervention period. This trial is registered with the UMIN Clinical Trial Registry (https://www.umin.ac.jp/: UMIN000046225).

Study outcome

The primary outcome will be a good functional outcome as determined by the mRS score at 90 days after stroke onset, with a target mRS score of 0–1 in the mild group, 0–2 in the moderate group, and 0–3 in the severe group.

Discussion

This trial may help determine whether RIC should be recommended as a routine clinical strategy for patients with ischemic stroke.

Direct Ischemic Postconditioning After Carotid Endarterectomy in the Prevention of Postoperative Cerebral Ischemic Complications—Observational Case–Control Study

Introduction:

Ischemic postconditioning (IPCT) represents one of the several therapeutic strategies to attenuate ischemic reperfusion injury (IR) after carotid endarterectomy (CEA). We here present the first in-human study of IPCT in carotid surgery.

Methods:

The study represents an observational case-control study, with the data collected in our Institution carotid database. From December 2015 to December 2020, a total of 300 patients were included in our study; IPCT group consisted of 148 patients in whom ischemic postconditioning was performed while control group consisted of 152 patients in whom IPCT was not performed. Indications for IPCT technique were: severe unilateral internal carotid artery (ICA) stenosis (>90%), severe bilateral ICA stenosis (>80%), severe ICA stenosis (>80%) with contralateral ICA occlusion and ICA subocclusion. IPCT was performed by applying 6 cycles of 30 sec reperfusion (declamping of ICA)/30 sec ischemia (clamping of ICA) after finishing the procedure and initial declamping. Two groups of patients were compared in terms of occurrence of intrahospital and early postoperative stroke, TIA (transient ischemic attack) and neurologic morbidity.

Results:

Cumulative incidence of intrahospital postoperative stroke or TIA was significantly higher in the control group (5.3% vs 0.7%, P = .036). According to carotid plaque characteristics, patients in the IPCT group had significantly more frequent presence of heterogenous plaque, as well as ulcerated plaque, which was associated with the absence of postoperative stroke and significantly lower cumulative rate of TIA/stroke when compared to the control group (43.9% vs 8% and 47.3% vs 1.5%). During the follow-up period of 1 month after the surgery, there were no cases of stroke, TIA and deaths due to neurological causes in both groups of patients.

Conclusion:

Our results showed that IPCT significantly reduced the incidence of postoperative cerebral ischemic complications after CEA in high-risk patients for IR injury when compared to the control group.