Resuscitative Endovascular Balloon Occlusion of the Aorta in Non-traumatic Out of Hospital Cardiac Arrest (REBOARREST)

Resuscitative Endovascular Balloon Occlusion of the Aorta in Non-traumatic Out of Hospital Cardiac Arrest

A Randomised Trial on Resuscitative Endovascular Balloon Occlusion of the Aorta in Non-traumatic Out of Hospital Cardiac Arrest

The primary aim of this trial is to assess the efficacy of resuscitative endovascular balloon occlusion of the aorta (REBOA) as an adjunct treatment to advanced cardiovascular life support (ACLS) in patients with out-of-hospital cardiac arrest. Out of hospital cardiac arrest (OHCA) carries a high mortality rate. The treatment of out-of-hospital cardiac arrest is ACLS as stated in the guidelines from the Norwegian Resuscitation Council and the European Resuscitation Guidelines. Recently, REBOA has been proposed as an adjunct treatment in management of non-traumatic cardiac arrest patients, because thoracic aortic occlusion provides a redistribution of the cardiac output to organs proximal to the occlusion. Preclinical studies demonstrate that REBOA during CPR provide both increased coronary artery blood flow and perfusion pressure and increased rates of return of spontaneous circulation (ROSC). This is the first prospective trial in the world to assess the efficacy of REBOA in non-traumatic cardiac arrest. The intervention is shown feasible in the pre-hospital setting. If this trial provides a signal of benefit in patients, this study could initiate further clinical research which could change current resuscitation practice world-wide.

This is a prospective, randomised, parallel group, multi-centre, phase II clinical trial. Patients are randomised in a 1:1 ratio to be included to the control group or the intervention group. The control group receives ACLS according to national guidelines, while the intervention group receives ACLS according to national guidelines and the REBOA procedure as an adjunct treatment. The REBOA procedure is performed by a team consisting of a physician (anesteshiologist) and a paramedic, working at a helicopter emergency medical service (HEMS) base. All operators will be properly educated and tested before they can include patients. If the patients in the intervention group achieves ROSC, the balloon will be deflated and post-ROSC treatment will be continued as per routine.

Resuscitative Balloon Occlusion of the Aorta after advanced cardiac life support if return of spontaneous circulation is not achieved

Treatment as described in the guidelines from the European Resuscitation Council, the Norwegian Resuscitation Council, and other local national guidelines

Proportion of patients that achieve return of spontaneous circulation (ROSC) with a duration of at least 20 minutes.

The proportion of patients surviving to 30 days with good neurologic status, defined as a modified Rankin scale (mRS) score 0-3.

Difference in end-tidal CO2 (EtCO2) measurements between control group and intervention group after aortic occlusion.

In the control group, EtCO2 is measured after airway management is completed. In the intervention group, EtCO2 is measured after airway management is completed, before balloon inflation and 30, 60 and 90 seconds after balloon inflation.

In the intervention group, intra-aortic blood pressure measurements from the REBOA catheter are recorded. This applies only to the catheters with CE/FDA approval for invasive blood pressure measurements and will therefore be assessed in a sub-group of the participants. Continuous registration of invasive blood pressure will start before aortic occlusion.

Echocardiography after admission, after a few days-up to one week and at discharge will be assessed - both from the control and intervention group.

Values of serum creatinine (umol/L) and urine output (ml/kg/h) will be combined to classify renal function according to the Acute Kidney Injury Network (AKIN) classification, into stage 1-3.

Exploratory outcome - difference in the need for renal replacement therapy between intervention and control group

Exploratory outcome - difference in the liver function (albumine) between intervention and control group

Exploratory outcome - difference in the liver function (ASAT/ALAT) between intervention and control group

assessment of all adverse events, both suspected and unsuspected, in both intervention and control group

Inclusion Criteria: out-of-hospital cardiac arrest non-traumatic cardiac arrest less than 10 minutes from debut of arrest to start of basic or advanced cardiac life support advanced cardiac life support is established and can be continued Exclusion Criteria: traumatic cardiac arrest, including strangulation, electrocution and patients rescued from avalanches accidental hypothermia with temperature < 32 0C suspected cerebral hemorrhage as etiology of the arrest suspected non-traumatic hemorrhage as etiology of the arrest pregnancy, obvious or suspected patient included to the study site's E-CPR protocol other factors as decided by the treatment team (environmental factors, safety factors and others)

The full study protocol, statistical analysis plan, information letter for consent and other trial documents will be published open access. The clinical study report and statistical analysis report will also be made openly available but may be altered to hide information that may lead to identification of individual study participants. These documents will be shared at HUNT Cloud.

Study protocol and ICF will be available before study start. SAP will be available before first interim analysis.

Individual level data will be made available to sponsor institutions on the REBOARREST data space in HUNT Cloud. Access will be controlled by a data processor agreement between the partner and funder. Pseudonymous individual level data collected during the trial, will be made available on request to researchers from other scientific institutions by approval of the project management to ensure that usage is compliant with privacy and consent requirements as well as conditions for attribution and usage. Data sharing with editors or peer-reviewers of scientific journals, conferences or the like will not require additional consent or data access agreement with sponsor, as such data will not be shared onward or used beyond reviewing this trial. After data sharing, the sponsor must be acknowledged in any publication resulting from the shared data. For closer collaboration attribution based on the Vancouver Convention will apply.

Brede JR, Lafrenz T, Klepstad P, Skjaerseth EA, Nordseth T, Sovik E, Kruger AJ. Feasibility of Pre-Hospital Resuscitative Endovascular Balloon Occlusion of the Aorta in Non-Traumatic Out-of-Hospital Cardiac Arrest. J Am Heart Assoc. 2019 Nov 19;8(22):e014394. doi: 10.1161/JAHA.119.014394. Epub 2019 Nov 11.

Brede JR, Skulberg AK, Rehn M, Thorsen K, Klepstad P, Tylleskar I, Farbu B, Dale J, Nordseth T, Wiseth R, Kruger AJ. REBOARREST, resuscitative endovascular balloon occlusion of the aorta in non-traumatic out-of-hospital cardiac arrest: a study protocol for a randomised, parallel group, clinical multicentre trial. Trials. 2021 Jul 31;22(1):511. doi: 10.1186/s13063-021-05477-1.