Ischemic Conditioning: Implications for Emergency Medicine

The potential mechanism and clinical application value of remote ischemic conditioning in stroke

Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. Different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.

Postpartum haemorrhage requiring transfusion and risk of cardiovascular disease later in life: a retrospective cohort study

OBJECTIVE

To determine whether postpartum haemorrhage (PPH) is associated with cardiovascular disease (CVD), including cerebrovascular and ischaemic heart disease beyond the peripartum period.

DESIGN

Population-based cohort study.

SETTING

Merged databases of the Korea National Health Insurance (KNHI) claims, National Health Screening Examination and National Health Screening Program for Infants and Children.

POPULATION

Women who gave birth in 2007 in the Republic of Korea and who were tracked through to 2015 for the occurrence of CVD.

METHODS

Patients were identified and the occurrences of PPH and transfusion were determined using the KNHI claims database. The occurrence of CVD was tracked through 2015 using codes from the International Classification of Diseases, tenth revision (ICD-10).

MAIN OUTCOME MEASURES

The risk of CVD after PPH.

RESULTS

Among 150 381 women who gave birth during the study period, 9107 were diagnosed with PPH and 899 were treated with transfusion. The risk of CVD in women with PPH was no different than in women without PPH, after adjustment (HR 1.03, 95% CI 0.93-1.13). The risk of CVD in women with PPH requiring transfusion was significantly increased compared with women without PPH, after adjustment (HR 1.60, 95% CI 1.25-2.06). The risk of CVD in women with PPH without transfusion was not significantly different compared with women without PPH (HR 0.96, 95% CI 0.86-1.07).

CONCLUSIONS

Postpartum haemorrhage (PPH) requiring transfusion is associated with an increased risk of CVD. Guidelines for management should be established, and further studies on the mechanisms involved should be conducted.

TWEETABLE ABSTRACT

PPH requiring transfusion is associated with an increased risk of CVD.

Feasibility of prehospital delivery of remote ischemic conditioning by emergency medical services in chest pain patients: protocol for a pilot study

Background

Remote ischemic conditioning (RIC) is a non-invasive procedure with hypothesized therapeutic benefits for patients experiencing an acute ST-elevation myocardial infarction (STEMI). Further study of emergency medical services (EMS) delivery of RIC in the prehospital setting is needed to inform the design and methods for future clinical trials of RIC in STEMI patients. The main objective of this pilot study is to assess the feasibility of prehospital delivery of RIC by EMS providers in the United States.

Methods

We will conduct a single-arm study of the standard RIC procedure (i.e., up to 4 cycles of alternating 5-min inflation and 5-min deflation of an upper arm cuff) administered by EMS paramedics in 50 patients experiencing acute onset chest pain. The investigational autoRIC® device (CellAegis Devices, Inc., Toronto, Ontario) will be initiated by paramedics during ground ambulance transport. Automated RIC cycles will continue through emergency department arrival and stay. The primary endpoint will be the completion of all 4 cycles of RIC without interruption. We will also examine study procedures and collect qualitative data from study participants and paramedics.

Discussion

To our knowledge, this will be the first study in the United States to assess the feasibility of completing the 40-min RIC procedure when initiated during ground ambulance transport. Findings from this pilot study will be used to optimize the design and methods for a future efficacy trial of RIC in acute STEMI patients.

Trial registration

NCT03400579 (ClinicalTrials.gov). Registered on 17 January 2018.