LAUSR

Introduction/Hypothesis: Initial electrocardiogram (ECG) rhythm is one of the factors predicting the outcome in out-ofhospital cardiac arrest (OHCA) patients who receive extracorporeal cardiopulmonary resuscitation (ECPR). Initial shockable cardiac rhythm is suggested as an indicator for the commencement of ECPR. However, ECG rhythm often changes before ECPR, and the cause for this change is unknown. In this study, we aimed to examine the relationship between conversion of ECG rhythm before ECPR and neurological outcomes. Methods: A retrospective analysis was performed in OHCA patients, who received ECPR between January 2010 and October 2017. Patients who presented with initial shockable cardiac rhythm were included in the study. The patients were classified into three groups: asystole group, patients whose ECG rhythm converted to asystole at any time before the initiation of ECPR; shockable group, patients whose ECG shockable rhythm remained persistent until the initiation of ECPR; and other group, patients whose ECG rhythm converted to another rhythm until the initiation of ECPR. The primary outcome was the mortality rate at the time of discharge from the hospital. A multivariable logistic regression analysis was performed to determine the relationship between conversion of ECG rhythm and mortality. Results: A total of 88 patients were included in the study. The median age of patients was 65 years and 53% survived to hospital discharge, of whom 25% of patients had a favorable neurologic outcome, which was defined as cerebral performance category of 1–2. There were 30, 31, and 27 patients in the asystole, shockable, and other groups, respectively. The mortality rates at the time of hospital discharge were 70.0% in the asystole group, 32.3% in the shockable group, and 37.0% in the other group (p = 0.006). Results of the multivariate analysis revealed that the asystole group exhibited a significant correlation with mortality (odds ratio, 7.77; 95% confidence interval, 2.27– 30.87; p < 0.001). Conclusions: Conversion of asystole before ECPR for OHCA patients was found to be associated with mortality even if the initial ECG rhythm was shockable rhythm.