Alerting nearby CPR-trained volunteers through a smartphone app did not increase the likelihood that a person experiencing cardiac arrest received CPR or use of an automated external defibrillator (AED) before professional responders arrived, according to preliminary research presented at the American Heart Association's Resuscitation Science Symposium 2026.
The study, conducted in British Columbia and Columbus, Ohio, randomly assigned cardiac arrest 911 calls to either standard emergency medical services (EMS) dispatch only or standard dispatch plus PulsePoint Respond alerts to nearby volunteers. PulsePoint Respond is a smartphone application that connects with local 911 dispatch centers to alert nearby people who have indicated they are willing and able to perform CPR. EMS agencies subscribe to the service for a fee, but the app is free for community first-responder volunteers.
Among 355 people included in the primary analysis, bystander CPR or AED use occurred in 69% of cardiac arrests when PulsePoint alerts were activated, compared with 72% with standard 911 response alone. The difference was not statistically significant. Bystander CPR occurred in 70% of the alert group and 73% of the standard dispatch group; bystander AED use occurred in 15% and 17%, respectively. About 21% of people in each group survived to hospital discharge.
"In the event of a cardiac arrest, calling 911 is essential, yet even a rapid professional response can take several minutes - time the person in cardiac arrest cannot afford to lose," said Steven Brooks, M.D., M.H.Sc., senior lead author and a professor in emergency medicine and public health sciences at Queen's University in Kingston, Ontario, Canada. "We found that bystander CPR was already common without alerts in the regions we studied. In the control group, 73% of patients received bystander CPR. This unexpectedly high rate of bystander CPR may have limited the opportunity for alerted responders to provide additional benefit."
The findings matter because they suggest that in communities where bystander CPR is already widely practiced, adding smartphone alerts may not meaningfully improve outcomes. The study included 17,547 randomly assigned 911 calls for possible cardiac arrest in public locations from June 2021 to March 2026. Most cardiac arrests analyzed occurred in urban locations (91%), and median time from 911 call to EMS arrival was 5.6 minutes in the alert group and 5.9 minutes in the no-alert group. In 57% of activated incidents, only one app user was within 400 meters, and 91% of incidents had four or fewer volunteer first-responders nearby.
The research has limitations: it focused on public locations with at least one nearby PulsePoint user, so findings may not apply to private homes, rural areas, or communities with different responder networks. The trial does not answer whether benefits would differ in those settings. "Although our study didn't show the PulsePoint smartphone alerts increasing bystander CPR and AED use in public locations, it will contribute evidence to help the global resuscitation community, emergency medical services and policymakers assess the potential of this approach to improve early bystander treatment," Brooks said.
The American Heart Association, which hosted the symposium, offers resources such as the 2025 American Heart Association Guidelines for CPR and ECC and encourages the public to Join the Nation of Lifesavers by learning CPR today. More information about the meeting is available on the About Resuscitation Science Symposium 2026 page. The association's financial information is available here, and general heart health information can be found at heart.org and stroke.org.
