The primary reason that the percentage of good recovery of patients with GCS motor response score 1 in our study (7/53, 13.2%) was lower than that in the study by Hifumi et al. [2] (130/249, 52 %) is that our study population included more severe patients, such as patients who underwent E-CPR and patients with non-cardiac cause for cardiac arrest such as hypoxia and hypovolemia. The study by Hifumi et al. did not include patients who underwent E-CPR or patients with non-cardiac cause for cardiac arrest.