Resuscitation in out-of-hospital cardiac arrest—how quickly it is done may be more important than who does it

Out-of-hospital cardiac arrest (OHCA) in people experiencing a heart attack is a time-dependent medical emergency requiring immediate cardiopulmonary resuscitation (CPR).

In new research presented at this year’s ESC Acute CardioVascular Care congress in Florence, Italy (14–15 March), a research team led by Prof. Aneta Aleksova, including Dr. Alessandra Lucia Fluca and Dr. Milijana Janjusevic from the University of Trieste, Italy, in collaboration with interventional cardiologist Dr. Andrea Perkan concludes that, while the proportion of bystanders (members of the public) performing CPR has increased over the past two decades in the Friuli Venezia Giulia Region (an autonomous region in northeastern Italy), the critical factor in determining survival and long-term outcomes is how quickly CPR is started, not who performs it.

More specifically, while it is encouraging that the number of bystander rescuers has increased compared to previous years, the fact that 80% of out-of-hospital cardiac arrests (OHCA) occur in residential settings highlights the crucial need for further public education and Basic Life Support (BLS) training to improve survival rates.

The authors conclude, “Over time, the proportion of layperson rescuers constantly increased. Rapid return of spontaneous circulation was was crucial for in-hospital survival, independently of rescuer type. Also, similar long-term survival was observed comparing patients with initial layperson or emergency medical service cardiopulmonary resuscitation. Our data highlights the importance of immediate resuscitation and underlines the importance to promote population awareness and BLS training to further improve survival after out-of-hospital cardiac arrest.”

The authors analyzed data from 3315 patients with ST-elevated myocardial infarction (STEMI), a type of heart attack caused by a complete blockage of a major heart artery, who were admitted to the cardiology department at University Hospital Trieste over the 22-year period (2003–2024). Among them, 172 suffered OHCA, and in total 44 received CPR from a bystander during the whole study period.

When the study period was divided into five intervals (2003–2007, 2008–2011, 2012–2015, 2016–2019 and 2020 to 2024), the authors observed a significant increase in the proportion of patients receiving bystander-initiated CPR throughout the years. Statistical analysis showed the proportion of patients receiving bystander CPR increased from 26% in 2003–2007 to 69% in 2020–2024.

The median time to return of spontaneous circulation (ROSC) was 10 minutes overall, but longer for bystanders (20 minutes) compared with medical operators (5 minutes). Patients who received bystander CPR more frequently underwent endotracheal intubation (ET) (91% for bystander CPR versus 65% for those receiving EMS CPR).

Overall, one quarter of the patients (25.6%) died in the initial period of hospital admission. Compared to survivors, patients who died in-hospital were older (mean age: 67 years versus 62 years) and had more comorbidities. Statistical analysis revealed worse left ventricular ejection fraction (LVEF), longer time to ROSC and older age were predictors of in-hospital mortality, after correction for rescuer type.

More precisely, each 5-minute increase in time to ROSC and a 5-percentage-point decrease in LVEF were associated with a 38% increased risk in mortality, whereas every 5-years increase in age corresponded to a 46% higher death risk. Then, during a median follow-up of 7 years, 18 patients (14%) died, but the authors’ analysis showed mortality did not differ based on rescuer type.

While these survival rates are higher than typically seen for OHCA patients, the authors explain that various factors could be behind this—the patients included in this study had STEMI-type heart attacks, from which the chances of recovery are higher (compared to patients with OHCA with other cardiac and extracardiac causes). Other factors could include higher than average proportions of bystanders trained in CPR, and strongly performing emergency health systems enabling operators to reach victims more rapidly.