Remote ischaemic conditioning: in search of a suitable match

Rationale and Design of the IMPROVE Trial: A Multicenter, Randomized, Controlled, Open-label, Blinded-endpoint Trial Assessing the Efficacy of Remote Ischemic Conditioning in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

INTRODUCTION

Despite the appearance of off-pump coronary artery bypass grafting (CABG), ischemia-reperfusion injury (IRI) in the perioperative period still arouses concerns of clinicians. Remote ischemic conditioning (RIC) is the process of repeated ischemia and reperfusion in the peripheral vessels, which is proven to reduce IRI in vital organs. However, the effect of RIC in patients undergoing off-pump CABG is still unclear.

METHODS

This IMPROVE trial is a national, multicenter, randomized, controlled, open-label, blinded-endpoint clinical trial designed to assess whether RIC intervention can improve short-term prognosis of patients undergoing off-pump CABG. It plans to enroll 648 patients who will be randomly assigned into a RIC group or control group. Patients in the RIC group will receive four cycles of 5 min of pressurization (about 200 mmHg) and 5 min of rest in the 3 days before and 7 days after the surgery.

PLANNED OUTCOMES

The primary outcome is the occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) within the 3-month follow-up. MACCE is defined as all-cause death, myocardial infarction, stroke, and coronary revascularization surgery.

CLINICAL TRIAL REGISTRATION

NCT06141525 (ClinicalTrials.gov).

Reperfusion Injury: How Can We Reduce It by Pre-, Per-, and Postconditioning

While early coronary reperfusion via primary percutaneous coronary intervention (pPCI) is established as the most efficacious therapy for minimizing infarct size (IS) in acute ST-elevation myocardial infarction (STEMI), the restoration of blood flow also introduces myocardial ischemia-reperfusion injury (IRI), leading to cardiomyocyte death. Among diverse methods, ischemic conditioning (IC), achieved through repetitive cycles of ischemia and reperfusion, has emerged as the most promising method to mitigate IRI. IC can be performed by applying the protective stimulus directly to the affected myocardium or indirectly to non-affected tissue, which is known as remote ischemic conditioning (RIC). In clinical practice, RIC is often applied by serial inflations and deflations of a blood pressure cuff on a limb. Despite encouraging preclinical studies, as well as clinical studies demonstrating reductions in enzymatic IS and myocardial injury on imaging, the observed impact on clinical outcome has been disappointing so far. Nevertheless, previous studies indicate a potential benefit of IC in high-risk STEMI patients. Additional research is needed to evaluate the impact of IC in such high-risk cohorts. The objective of this review is to summarize the pathophysiological background and preclinical and clinical data of IRI reduction by IC.

Remote ischemic conditioning in septic shock: the RECO-Sepsis randomized clinical trial

PURPOSE

To determine whether remote ischemic conditioning (RECO), compared to standard care, limits the severity and the consequences of multiple organ failure in patients with septic shock.

METHODS

The RECO-Sepsis trial, a prospective, multicenter, randomized, open-label, parallel group trial with blinded assessment of the outcome, was conducted at six intensive care units in France in adult patients with septic shock. Within 12 h after the onset of septic shock, patients were randomized (1:1 ratio) to receive either RECO applied by inflating/deflating (200/0 mmHg for 5/5 min) 4 times a cuff around an arm or a sham procedure every 12 h for 24 h. The primary endpoint was the severity of multiple organ failure assessed by the mean daily Sequential Organ Failure Assessment (SOFA) score from inclusion to the fourth day after inclusion (day 4). Patients were followed for 90 days.

RESULTS

Among 180 randomized patients, 178 completed the trial (RECO group: 87; control group: 91) and were included in the intention-to-treat analysis (108 men [60.7%], median age 68 [59-75] years). There was no significant difference in the mean daily SOFA score between the intervention group and the control group (7.2 points [5.2-10.7] versus 7.6 points [4.9-10.7], respectively; p = 0.919). Cumulative mortality within 90 days was 27.6% in the RECO group and 39.6% control group (Log-rank test, p = 0.10; adjusted hazard ratio 0.59, 95% CI, 0.35 to 0.99; p = 0.049).

CONCLUSIONS

In patients with septic shock, RECO failed to reduce the severity of organ failures assessed by mean daily SOFA score from inclusion to day 4. Adequately powered trials are needed to assess potential delayed benefits of RECO.

IMproving Preclinical Assessment of Cardioprotective Therapies (IMPACT) criteria: guidelines of the EU-CARDIOPROTECTION COST Action

Acute myocardial infarction (AMI) and the heart failure (HF) which may follow are among the leading causes of death and disability worldwide. As such, new therapeutic interventions are still needed to protect the heart against acute ischemia/reperfusion injury to reduce myocardial infarct size and prevent the onset of HF in patients presenting with AMI. However, the clinical translation of cardioprotective interventions that have proven to be beneficial in preclinical animal studies, has been challenging. One likely major reason for this failure to translate cardioprotection into patient benefit is the lack of rigorous and systematic in vivo preclinical assessment of the efficacy of promising cardioprotective interventions prior to their clinical evaluation. To address this, we propose an in vivo set of step-by-step criteria for IMproving Preclinical Assessment of Cardioprotective Therapies ('IMPACT'), for investigators to consider adopting before embarking on clinical studies, the aim of which is to improve the likelihood of translating novel cardioprotective interventions into the clinical setting for patient benefit.