Public Access Defibrillation by Activated Volunteer Citizen Responders — the HeartRunner Trial

HeartRunner

Patient / Population Intervention / Exposure Comparison Outcome

In 2,114 out-of-hospital cardiac arrests, smartphone activation of citizen responders did not improve survival at 30 days compared with standard EMS response.

N

2,060patients

Design

Investigator-initiated, dispatcher- and investigator-blinded, 1:1 randomised superiority trial in the Capital Region of Denmark (May 2019 – March 2026); unit of randomisation is the dispatcher-identified suspected-OHCA alarm, randomised automatically on the HeartRunner server by permuted blocks within three strata of predicted citizen-responder arrival time (<3 min, 3–9 min, >9 min; powered for strata 1 and 2 at 80%); intention-to-treat; 30-day vital status from the Danish Civil Registry; Bayesian analysis pre-specified as supplementary

Endpoint

30-day survival

Relevance

2Important — one of several pillars.

ResultNo difference in 30-day survival: 15% vs 17% where responders arrived within 3 minutes (P = 0.42) and 13% vs 14% at 3 to 9 minutes (P = 0.43). In the 3-to-9-minute stratum bystander CPR rose from 75% to 86% and bystander defibrillation from 6% to 14% (both P < 0.0001).

Folke F, Andelius L, Ersbøll AK, et al. Public access defibrillation by activated community first responders – the randomized HeartRunner trial. Resusc Plus. 2026;31:101420 (trial design/rationale). Primary results presented at ESC Congress 2026, Hot Line 12, 31 August 2026.

Discussion & critique

Smartphone-dispatched volunteers did what they were asked to do — bystander CPR from 75% to 86%, bystander defibrillation from 6% to 14% — and 30-day survival did not move. That gap is the finding: the process measures the system optimises for are not the outcome, at least not in Copenhagen, where the ambulance response is already fast and baseline bystander CPR already high. A country with slower response times or less trained bystanders might see a different answer, and this trial cannot supply it.