Abstract 111: Impact of Time to Return of Spontaneous Circulation on Neurologically Intact Survival in Patients With Out-of-Hospital Cardiac Arrest According to Age: Evidence From a Large-Scale Registry in Japan

Abstract

Introduction: Time to return of spontaneous circulation (ROSC) is a more important predictor of neurologically intact survival than the presence of ROSC in patients with out-of-hospital cardiac arrest (OHCA). However, the differences in the relationship between time to ROSC and neurologically intact survival in patients with OHCA based on age is unclear. Hypothesis: We hypothesized that the impact of time to ROSC on neurologically intact survival differs according to age. Methods: We analyzed the data of 34,905 patients with OHCA (age ≥18 years) who exhibited prehospital ROSC from the prospectively recorded all-Japan OHCA registry (2011-2014). The primary outcome was neurologically intact survival at 1 month after OHCA (cerebral performance category [CPC] 1 or 2). Time to ROSC was defined as the interval from the initiation of cardiopulmonary resuscitation (CPR) by emergency medical service (EMS) providers to the achievement of ROSC. We categorized time to ROSC by every 4-min interval (2 cycles of CPR) from 1 to 32 min and ≥33 min, and age into 4 groups: 18-64, 65-74, 75-89, and ≥90 years. Results: The overall CPC 1-2 rate was 21.1% (7,353/34,905). Increasing time to ROSC (per min) was negatively associated with CPC 1-2 (adjusted odds ratio, 0.91; 95% confidence interval, 0.90-0.91). The CPC 1-2 rates decreased as time to ROSC increased in each age group: from 58.8% (1,247/2,122) in 1-4 min to 2.8% (7/246) in ≥33 min for patients aged 18-64 years, from 51.1% (721/1,410) in 1-4 min to 1.6% (4/244) in ≥33 min for 65-74 years, from 37.3% (765/2,051) in 1-4 min to 0.7% (4/539) in 29-32 min for 75-89 years, and from 23.4% (92/393) in 1-4 min to 0.2% (1/481) in 17-20 min for ≥90 years (all p for trend <0.001). Conclusions: The CPC 1-2 rates of patients aged 18-64 and 65-74 years were above the 1% futility rate when prehospital ROSC was achieved after prolonged CPR, ≥33 min from initiation by EMS providers. However, the CPC 1-2 rates were below the 1% futility rate when prehospital ROSC was achieved ≥29 min and ≥17 min for patients aged 75-89 years and ≥90 years, respectively.