ECMO Used in a Refractory Ventricular Tachycardia and Ventricular Fibrillation Patient: A National Case-Control Study

Refractory cardiac arrhythmia, which has a poor response to defibrillation and antiarrhythmia medication, is a complicated problem for clinical physicians during resuscitation. Extracorporeal membrane oxygenation (ECMO) may be used to sustain life in this situation. ECMO is useful for cardiopulmonary resuscitation among patients suffering from cardiac arrest; the use of ECMO in this context is called E-cardiopulmonary resuscitation. However, a large-scale and nationwide survey of ECMO usage in cases involving refractory cardiac arrhythmia during resuscitation is lacking. We aimed to clarify the characteristics and efficacy of the application of ECMO in cases involving refractory cardiac arrhythmia during resuscitation by conducting a nationwide study. Using national insurance data from 1996 to 2011, 2702 patients who received defibrillation and amiodarone injections were selected. We excluded trauma patients (n = 316) and those aged<20 years (n = 24). A total of 2362 patients were included, 376 of whom had ECMO support, and 1986 of whom had no ECMO support. After propensity score matching, 320 patients had ECMO support and 640 patients without ECMO support. Conditional logistic regression was used to estimate the risk of death in ECMO users compared to non-EMCO users. ECMO used in refractory cardiac arrhythmia with high propensity score patients had lower risk of death (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.36-0.98). However, prolonged ECMO used >1 day was higher risk of death (OR = 2.88, 95% CI = 1.27-6.53). In our retrospective case control study in refractory cardiac arrhythmia patients, ECMO supportive in high propensity score patients showed improving the overall survival rate but ECMO support for >1 day would be harmful. The evidence derived from this retrospective study using data from the national insurance system is generally of lower methodological evidence than that from randomized controlled trials because a retrospective study is subject to many biases due to lack of the necessary adjustments for possible confounding factors. Therefore, further investigation with a randomized clinical trial is needed to recommend ECMO as a routine in this specific population of patients experiencing cardiac arrest and refractory VT and VF.