Abstract 13984: Extracorporeal Cardiopulmonary Resuscitation for Unwitnessed Cardiac Arrest

Extracorporeal Cardiopulmonary Resuscitation for Unwitnessed Cardiac Arrest Introduction: An unwitnessed cardiac arrest has worse prognosis compared to a witnessed cardiac arrest. Extracorporeal cardiopulmonary resuscitation (ECPR) using venoarterial extracorporeal membrane oxygenation (ECMO) may improve outcomes for patients after cardiac arrest. Hypothesis: We assessed the hypothesis that ECPR will improve patient outcomes following an unwitnessed and refractory cardiac arrest. Methods: Patients who were treated with ECPR were enrolled in this study. We divided the patients into two groups based on whether their cardiac arrest was witnessed or unwitnessed. We assessed baseline patient characteristics, 30-day survival, and neurological outcomes. Results: The patients age in years (median 65 [interquartile range 56 - 72] vs. 60 [50 - 74], P = 0.74) and the rate of initially recorded shockable rhythms (39% vs. 33%, P = 0.70) were similar between the patients in the witnessed group (N = 172) and those in the unwitnessed group (N = 15). The duration of cardiopulmonary resuscitation was longer for patients in the unwitnessed group than for those in the witnessed group (66 [44 - 77] min vs. 45 [24 - 62] min, P = 0.004). The rates of performing immediate coronary angiography (75% vs. 87%, P = 0.53), coronary revascularization (44% vs. 33%, P = 0.44), and targeted temperature management (55% vs. 47%, P = 0.55) were similar between the two groups. The rate of return of spontaneous heart beat (91% vs. 60%, P = 0.003) was lower in the unwitnessed group. The rates of weaning from ECMO (44% vs. 27%, P = 0.19) were similar between the two groups. The 30-day survival curves are shown in Figure. There were no favorable neurological outcomes (Cerebral Performance Category scale of 1 or 2) in the unwitnessed group. Conclusions: ECPR may not improve patient outcome following unwitnessed arrest even in patients who were initially found to have a shockable rhythm.