A large-scale, five-year randomized trial conducted across 60 counties in North Carolina has found that a comprehensive community and emergency medical services (EMS) educational intervention did not significantly improve survival to hospital discharge with favorable brain function for adults who experienced out-of-hospital cardiac arrest. The results, presented at the American Heart Association's Scientific Sessions 2026 and simultaneously published in the New England Journal of Medicine, highlight the challenges of translating community education into measurable survival gains, even as they offer clues about what might work with more time.
The trial, known as RACE-CARS, randomly assigned 31 counties to receive an intensive intervention that included community-wide CPR training, 9-1-1 dispatcher training to guide callers through CPR, and enhanced first-responder efforts such as increased defibrillation before EMS arrival. The remaining 29 counties continued their usual practices. Over the study period, 11,615 people experienced out-of-hospital cardiac arrest in intervention communities, compared with 10,844 in control communities. Survival with favorable brain function was about 9% in both groups—9% in intervention counties versus 9.4% in control counties—a difference that was not statistically significant.
Bystander CPR rates were also similar overall: 44.8% in intervention communities versus 42.3% in control communities. Early defibrillation before EMS arrival occurred in 13.5% of cases in intervention communities and 15.3% in control communities. However, an exploratory analysis revealed a notable signal: during the final year of the study, people in intervention communities had 33% higher odds of receiving bystander CPR than those in control communities. This finding suggests that sustained community outreach may eventually improve bystander response, but the effect may take years to manifest.
“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 Christopher Granger, M.D., FAHA, the trial principal investigator and a cardiologist at Duke University. The study's size and scope—covering approximately 8.5 million residents, including rural areas—was a key strength, but implementation varied widely. For instance, community partners conducted 5,724 CPR training events reaching 201,586 people, or 4.8% of residents in intervention counties, with participation ranging from over 10% in four counties to under 3% in eight counties.
The findings underscore the difficulty of changing community response to cardiac arrest, a time-critical emergency in which survival decreases by 10% for every minute without CPR. According to the American Heart Association's 2026 Heart Disease and Stroke Statistics, about 350,000 Americans experience out-of-hospital cardiac arrest each year, and only about 1 in 10 survive. Immediate CPR can double or triple survival chances, yet only about 40% of victims receive bystander CPR, and only 10% have an automated external defibrillator applied before EMS arrives, according to the Association's AED Fact Sheet.
“Changing how an entire community responds to cardiac arrest takes time, and our findings show just how challenging that can be,” said lead author Carolina Malta Hansen, M.D., Ph.D., a cardiologist at Herlev and Gentofte Hospital and Copenhagen EMS in Denmark. “In the meantime, the message to the public remains simple: learn CPR, recognize the signs of cardiac arrest, call 9-1-1 immediately and follow the dispatcher's instructions.” The American Heart Association's 2025 Guideline for CPR and emergency cardiovascular care reinforces these steps, and the Association's Nation of Lifesavers initiative aims to double survival rates by 2030 through expanded education. As the trial shows, such efforts may require persistent, long-term investment to translate into saved lives.
