Abstract 2506: Effect of Extracorporeal CPR for Witnessed Out-of Hospital Cardiac Arrest of Presumed Cardiac Origin
Background: Extracorporeal cardiopulmonary resuscitation (ECPR) has been shown to improve outcome of in-hospital cardiac arrest. Although there were uncontrolled studies regarding ECPR followed by induction of therapeutic hypothermia for out-of hospital cardiac arrest (OHCA), an independent effect of ECPR for OHCA was unknown. Our aims were:
to assess whether ECPR was better than conventional CPR (CCPR) for witnessed OHCA of presumed cardiac origin and
to analyze pre-ECPR variables to predict outcome in ECPR patients.
Methods: We conducted a retrospective cohort study of witnessed OHCA adult patients of presumed cardiac origin who were referred to a single tertiary care center over 4 years period. The decision to install ECPR was made by the attending emergency physicians in charge. We used propensity-score matching to adjust for differences between ECPR patients and CCPR patients. Outcome measures were survival to discharge and favorable neurological status at discharge. The independent effect of ECPR in matched patients was determined using multivariable Cox regression model. The independent pre-ECPR predictor of outcome in ECPR patients was determined using multivariable logistic regression model.
Results: Of 185 eligible patients, 134 were enrolled in the CCPR group and 51 were enrolled in the ECPR group. The propensity-score matching process selected 26 patients each from both groups. In multivariable Cox regression analysis, There was a significant difference favoring ECPR over CCPR in survival to discharge (adjusted HR 0.48, 95%CI 0.24 – 0.94, p=0.031) and favorable neurological status at discharge (adjusted HR 0.51, 95%CI 0.27– 0.99, p=0.047). In multivariable logistic regression analysis of the ECPR group, pupil diameter on ED arrival could predict for survival to discharge (+1 mm, adjusted OR 0.43, 95%CI 0.21– 0.87, p=0.019), but none of pre-ECPR variables was a significant predictor of favorable neurological status at discharge.
Conclusion: Our findings suggested that ECPR was superior to CCPR for witnessed OHCA of presumed cardiac origin and pupil diameter on ED arrival was a key predictor of survival in ECPR patients. Further study is needed to identify potential determinants in OHCA patients who could benefit from ECPR.