Public access defibrillation by activated community first responders - the randomized HeartRunner trial

The HeartRunner trial was an investigator-initiated, randomized clinical controlled trial (RCT) examining whether community first responders (CFRs) activated through a smartphone application can improve survival after out-of-hospital cardiac arrest (OHCA).

The study compared standard care alone versus standard care with the addition of dispatched CFRs for patients with OHCA.

The trial was conducted in the Capital Region of Denmark, with a catchment area of approximately 1.9 million inhabitants. By May 2019, 15,401 citizens had registered to serve as CFRs (837/100,000 inhabitants) and roughly 6200 automated external defibrillators (344/100,000 inhabitants) were publicly accessible in the study area (2.4 defibrillators per km²).The primary outcome was 30-day survival. Secondary outcomes included bystander defibrillation, bystander cardiopulmonary resuscitation, return of spontaneous circulation before hospital arrival, favorable neurological outcome at hospital discharge, and 1-year survival. As safety outcomes, the trial examined the potential physical or psychological risk involved for the activated CFR. The trial was expected to randomize 4188 cases of suspected OHCAs over a period of 7 years and was terminated February 28, 2026, when inclusion was completed. The full study protocol is available at www.clinicaltrials.gov (identifier: NCT03835403).