Relationship between neurologically intact survival and time interval from collapse to return of spontaneous circulation in patients with out-of-hospital cardiac arrest

Background: Early achievement of Return Of Spontaneous Circulation (ROSC) after cardiac arrest is critical to neurologically intact survival, but few data are available comparing this factor in various cardiac arrest rhythms. Methods: From the All-Japan Utstein Registry between 2005 and 2010, 12,566 adult viticums who had bystander-witnessed out-of-hospital cardiac arrest due to cardiac etiology, whose arrest rhythm was confirmed by emergency medical service responders on arrival at the scene and whose ROSC was identified on arrival at the hospital were included; 7,282 (58%) had ROSC from shockable arrest, 3,140 (25%) from pulseless electrical activity (PEA) and 2,134 (17%) from asystole. The study endpoint was favorable neurological outcome 30 days after cardiac arrest. Results: Among the three arrest groups, significant differences were seen in the collapse-to-ROSC interval (median; 16 minutes in the shockable arrest group, 20 minutes in the PEA group, 26 minutes in the asystole group, p<0.001) and in frequency of 30-day favorable neurological outcome (52.8% in the shockable arrest group, 13.3% in the PEA group, 4.1% in the asystole group, p<0.001). Likelihood of favorable neurological outcome decreased in each group for every 1 minute increment in the collapse-to-ROSC interval (adjusted OR; 0.93 in the shockable arrest group and PEA group, and 0.91 in the asystole group). For every minute that passes between collapse and ROSC, frequency of favorable neurological outcome decreased from 90% to 0% over a 60 minute period in the shockable arrest group, from 50% to 0% over a 50 minute period in the PEA group, and from 40% to 0% over a 40 minute period in the asystole group. Conclusion: Collapse-to-ROSC interval for the attainment of neurologically intact survival differed among cardiac arrest rhythms. The marginal collapse-to-ROSC interval was 60 minutes in shockable arrest, 50 minutes in PEA and 40 minutes in asystole.