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Prehospital REBOA Shows No Significant Improvement in ROSC for Non-Traumatic Cardiac Arrest
In a randomised controlled trial of 179 adults with non-traumatic out-of-hospital cardiac arrest, adding prehospital resuscitative endovascular balloon occlusion of the aorta (REBOA) to standard advanced life support did not meaningfully increase sustained return of spontaneous circulation compared with advanced life support alone (28% vs 26%; adjusted risk difference 1.8%, 95% CI −11 to 15; p=0.78). The effect estimate is small and the confidence interval spans both a modest benefit and a modest harm, indicating substantial uncertainty around any true treatment effect.
What Was Studied
The trial investigated whether deploying REBOA in the prehospital setting, as a complement to standard advanced life support, could improve rates of sustained return of spontaneous circulation in adults experiencing non-traumatic out-of-hospital cardiac arrest. The physiological premise was that balloon occlusion of the thoracic aorta during resuscitation might augment aortic pressure and coronary perfusion pressure, potentially improving the likelihood of restoring a stable cardiac rhythm.
How It Was Studied
REBOARREST was a pragmatic, open-label, parallel-group randomised controlled trial conducted across 12 sites in Norway, Denmark, and Italy, enrolling patients between June 2021 and June 2025. Adults aged 18–80 years with non-traumatic out-of-hospital cardiac arrest were randomly assigned in a 1:1 ratio to receive either standard advanced life support alone (control group) or advanced life support combined with prehospital REBOA (intervention group). Eligibility was determined by the physician present on scene, with sealed envelopes used for allocation. Of the 200 patients initially randomised, 21 withdrew due to lack of consent, leaving 88 patients in the intervention group and 91 in the control group for analysis on an intention-to-treat basis. The primary outcome was sustained return of spontaneous circulation, defined as lasting at least 20 minutes.
What Was Observed
- No significant difference in sustained ROSC: Rates of sustained return of spontaneous circulation were nearly identical between groups — 25 of 88 patients (28%) in the REBOA group versus 24 of 91 patients (26%) in the control group. The adjusted risk difference of 1.8% (95% CI −11 to 15; p=0.78) indicates no statistically significant benefit and an imprecise estimate consistent with both small benefit and small harm.
- Procedure was feasible and operationally manageable: Prehospital REBOA deployment was reported as feasible and achievable by a two-person team with low procedure time, suggesting that the absence of benefit was not attributable to implementation failure or excessive procedural burden during active resuscitation.
- Adverse events were limited in number: Adverse events were recorded in 19 of 179 patients across both groups, and the investigators characterised the procedure as safe in the prehospital environment, though detailed breakdown by group and event type is not reported in the abstract.
Why This Matters
REBOA has been explored as a means of improving perfusion during cardiac arrest by redirecting blood flow to the coronary and cerebral circulations, yet evidence for its efficacy outside trauma settings has remained limited. This trial represents a direct randomised test of that premise in the prehospital environment, finding no improvement in ROSC rates despite the technique being operationally viable. The result challenges the physiological rationale for routine prehospital REBOA use in non-traumatic cardiac arrest and provides a substantive evidence base to inform future resuscitation research priorities and resource allocation decisions.
How to Read This Result
While this is a well-designed multicentre randomised trial, the relatively long median time from arrest to randomisation (29–33 minutes across groups) may have reduced any window for REBOA to exert a haemodynamic benefit, and the sample size of 179 patients means the trial may lack power to detect smaller but potentially meaningful differences in outcome.
Limitations
Twenty-one patients were excluded after initial randomisation due to lack of consent, reducing the analysable sample from 200 to 179 and introducing a minor risk of selection bias. The median time from cardiac arrest to randomisation was approximately 29–33 minutes, which is relatively late in the resuscitation window and may have attenuated any potential haemodynamic effect of aortic occlusion. The open-label design, while pragmatic and unavoidable given the nature of the intervention, cannot exclude the possibility of performance bias in how resuscitation was conducted across the two groups.