A sweeping five-year randomized trial across 60 North Carolina counties found that a comprehensive community and emergency medical services education program did not significantly improve survival with favorable brain function for adults who suffered cardiac arrest outside a hospital, according to late-breaking science presented at the American Heart Association's Scientific Sessions 2026 in Chicago. The results matter because out-of-hospital cardiac arrest remains one of the deadliest emergencies in the United States, and the trial tested whether educating entire communities could move that needle.
The RACE-CARS trial, simultaneously published in the New England Journal of Medicine, randomly assigned 31 counties to receive the intervention and 29 to continue existing practices. The program combined community-wide CPR training delivered free through schools, workplaces, county government and other organizations with an EMS component that trained 9-1-1 dispatchers to recognize cardiac arrest and coach callers through bystander CPR, plus enhanced first-responder efforts and greater use of an automated external defibrillator before EMS arrival.
Over the study period, 11,615 people experienced out-of-hospital cardiac arrest in intervention communities and 10,844 in comparison communities. About 9% of patients in intervention counties survived to hospital discharge with favorable brain function, compared with 9.4% in counties without the program. Bystanders performed CPR in 44.8% of cardiac arrests in intervention communities versus 42.3% elsewhere, while defibrillation before EMS arrived occurred in 13.5% of intervention cases compared with 15.3% in comparison communities.
The most striking signal came late. In an exploratory analysis of the study's final year, people who suffered cardiac arrest in program communities had 33% higher odds of receiving bystander CPR than those in communities outside the program. "The increase in bystander CPR toward the end of the study shows there was some effect and suggests that a sustained community outreach may be needed to show an improvement in survival," said principal investigator Christopher Granger, a cardiologist and professor at Duke University.
Community partners conducted 5,724 CPR training events reaching 201,586 people, or 4.8% of residents in intervention communities, though participation varied widely, with four counties reaching more than 10% of residents and eight reaching fewer than 3%. Of 31 counties receiving 405 trial-provided defibrillators, 26 deployed the devices, 19 placed them in publicly accessible locations and 18 deployed them with first responders. Staffing shortages at 9-1-1 centers, the COVID-19 pandemic and Hurricane Helene created operational challenges.
The stakes are considerable. According to the American Heart Association's 2026 Heart Disease and Stroke Statistics, roughly 350,000 people in the U.S. experience out-of-hospital cardiac arrest each year, and only about one in 10 survives. The association's 2025 Guideline for CPR and emergency cardiovascular care stresses rapid recognition, calling 9-1-1, starting CPR and using an AED. Yet only about 40% of victims receive bystander CPR and only 10% have an AED applied by a bystander before EMS arrives, according to the association's AED Fact Sheet.
Study author Carolina Malta Hansen, a cardiologist at Herlev and Gentofte Hospital and Copenhagen EMS in Denmark, noted that survival odds fall 10% for every minute without CPR while waiting for EMS. She said the public message remains simple: learn CPR, recognize the signs, call 9-1-1 and follow dispatcher instructions. The association's Nation of Lifesavers initiative aims to double sudden cardiac arrest survival by 2030 and has raised U.S. bystander CPR confidence from 33% to 39% since 2023. The trial was funded by the National Institutes of Health and National Heart, Lung, and Blood Institute, with findings detailed in the abstract and the meeting's Online Program Planner.
