Abstract Body: Introduction: Each year in the U.S., over 350,000 people experience out-of-hospital cardiac arrests (OHCA), with a survival rate of just 10%. Most do not receive bystander CPR before professional rescuers arrive. Telecommunicator CPR (T-CPR) allows dispatchers to guide callers in performing CPR, a practice recommended by the American Heart Association (AHA). This study investigates the association between T-CPR and time to first compression and clinical outcomes.

Methods: This analysis included all OHCAs in North Carolina (NC) from July 1, 2022, to December 31, 2023, with data from the RACE-CARS trial embedded in the Cardiac Arrest Registry to Enhance Survival (CARES) dispatch module. Exclusions were pediatric, traumatic, EMS-witnessed arrests, cases in healthcare facilities, and cases where CPR was already in progress or data on dispatcher recognition of need for CPR were missing. The primary outcome was survival to hospital discharge with good neurological function (cerebral performance category 1 or 2).

Results: Overall,1,903 OHCA cases met the inclusion criteria. Median (25^th - 75^th percentiles) age was 64 (50-75) years, 29.0% were Black, and 37.6% were female. Dispatchers recognized the need for CPR in 81.6% of cases and chest compressions were initiated in 63.0%. Median times from call receipt were: 87 sec (52-158) to recognition of cardiac arrest, 137 sec (88-215) to T-CPR instructions, and 213 sec (151-293) to first compression. Of the 997 cases with information available, 24.6% met the AHA-recommended time of <150 sec from call to first chest compression. Among patients meeting those criteria, there was a trend towards higher survival with good neurological outcomes compared to those that did not meet the benchmark (10.2% vs. 8.3%, p=0.4).

Conclusions: In this contemporary OHCA population in NC, the AHA benchmark of median time from call to recognition of <90 sec was met while the benchmark for time from call to first chest compression <150 sec was not met in most cases. In patients with time to first chest compression of <150 sec, a numerically higher survival rate with good neurological outcome was observed but this was not statistically significant. These results emphasize the need for enhanced strategies to overcome barriers and improve T-CPR performance as part of the comprehensive strategy to improve cardiac arrest survival. Further analyses with adjustments for confounders are necessary to fully understand the implications of these findings.