Background— Sudden cardiac arrest is a leading cause of death in children and young adults. This study determined the incidence, cause, and outcomes of cardiovascular-related out-of-hospital cardiac arrest (OHCA) in individuals <35 years of age. Methods and Results— A retrospective cohort of OHCA in children and young adults from 1980 through 2009 was identified from the King County (Washington) Division of Emergency Medical Services' Cardiac Arrest Database. Incidence was calculated from population census data and causes of arrest determined by review of autopsy reports and all available medical records. A total of 361 cases (26 cases 0–2 years of age, 30 cases 3–13 years of age, 60 cases 14–24 years of age, and 245 cases 25–35 years of age) of OHCA were treated by emergency medical services responders, for an overall incidence of 2.28 per 100 000 person-years (2.1 in those 0–2 years of age, 0.61 in those 3–13 years of age, 1.44 in those 14–24 years of age, and 4.40 in those 25–35 years of age). The most common causes of OHCA were congenital abnormalities in those 0 to 2 years of age (84.0%) and 3 to 13 years of age (21%), presumed primary arrhythmia in those 14 to 24 of age (23.5%), and coronary artery disease in those 25 to 35 years of age (42.9%). The overall survival rate was 26.9% (3.8% in those 0–2 years of age, 40.0% in those 3–13 years of age, 36.7% in those 14–24 years of age, and 27.8% in those 25–35 years of age). Survival increased throughout the study period from 13.0% in 1980 to 1989 to 40.2% in 2000 to 2009 ( P <0.001). Conclusions— The incidence of OHCA in children and young adults is higher than previously reported, and a more specific understanding of the causes should guide future prevention programs. Survival trends support contemporary resuscitation protocols for OHCA in the young.

Dispatcher instruction consisting of chest compression alone did not increase the survival rate overall, although there was a trend toward better outcomes in key clinical subgroups. The results support a strategy for CPR performed by laypersons that emphasizes chest compression and minimizes the role of rescue breathing. (Funded in part by the Laerdal Foundation for Acute Medicine and the Medic One Foundation; ClinicalTrials.gov number, NCT00219687.)

Background-The incidence of sudden cardiac death is roughly 3 times greater in men than in women. However, in patients treated for out-of-hospital cardiac arrest, the relationships between sex and survival after adjustment for age and cardiac rhythm are unclear. Methods and Results-In this retrospective cohort study, we examined 7069 men and 2582 women who were treated for out-of-hospital cardiac arrest in Seattle and suburban King County between 1990 and 1998. We compared successful prehospital resuscitation (hospital admission) and survival from event to discharge in men and women. Women had markedly reduced rates of ventricular fibrillation (VF), slightly older age, fewer witnessed arrests, and fewer arrests in public locations than men. Although their unadjusted resuscitation rate was lower (29% versus 32%, PϽ0.0001), women had a greater likelihood of resuscitation than men after adjustment for VF (odds ratio [OR] 1.13; 95% confidence interval [CI], 1.03 to 1.25) and after adjustment for VF plus additional factors (OR, 1.27; 95% CI, 1.14 to 1.41). The difference in resuscitation rates between men and women decreased as they aged (test for trend, PϽ0.0001). Unadjusted survival rates were also lower in women than in men (11% versus 15%, PϽ0.0001). Women had similar survival after adjustment for VF (OR, 0.97; 95% CI, 0.85 to 1.11) and after adjustment for VF plus additional factors (OR, 1.09; 95% CI, 0.93 to 1.27). Conclusions-The lower unadjusted resuscitation and survival rates observed in women were primarily due to women's lower incidence of VF, a relatively favorable cardiac rhythm. After adjustment for VF and other factors, women had higher resuscitation rates than men, but similar rates of survival from event to discharge.