title: Amiodarone or nifekalant upon hospital arrival for refractory ventricular fibrillation after out-of-hospital cardiac arrest.
abstract: We evaluated the association between nifekalant or amiodarone on hospital admission and in-hospital mortality for cardiac arrest patients with persistent ventricular fibrillation on hospital arrival.
  
  
  
  This was a retrospective cohort study using the Japanese Diagnosis Procedure Combination inpatient database. We identified 2961 patients who suffered cardiogenic out-of-hospital cardiac arrest and who had ventricular fibrillation on hospital arrival between July 2007 and March 2013. Patients were categorized into amiodarone (n=2353) and nifekalant (n=608) groups, from which 525 propensity score-matched pairs were generated.
  
  
  
  We found a significant difference in the admission rate between the nifekalant and amiodarone groups in propensity score-matched groups (75.6% vs. 69.3%, respectively; difference, 6.3%; 95% confidence interval (CI), 0.9-11.7). An analysis using the hospital nifekalant/amiodarone rate as an instrumental variable found that receiving nifekalant was associated with an improved admission rate (22.2%, 95% CI, 11.9-32.4). We found no significant difference in in-hospital mortality between the nifekalant and amiodarone groups (81.5% vs. 82.1%, respectively; difference, -0.6%; 95% CI, -5.2 to 4.1). Instrumental variable analysis showed that receiving nifekalant was not associated with reduced in-hospital mortality (6.2%, 95% CI, -2.4 to 14.8).
  
  
  
  This nationwide study suggested no significant in-hospital mortality association between nifekalant and amiodarone for cardiogenic out-of-hospital cardiac arrest patients with ventricular fibrillation/persistent ventricular tachycardia on hospital arrival. Although nifekalant may potentially improve hospital admission rates compared with amiodarone for these patients, further studies are required to confirm our results.
authors: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Japan; Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan. Electronic address: t-tagami@nms.ac.jp.
authors: Takashi
authors: T
authors: Tagami
authors: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Japan.
authors: Hiroki
authors: H
authors: Matsui
authors: Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan.
authors: Saori
authors: S
authors: Ishinokami
authors: Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan.
authors: Masao
authors: M
authors: Oyanagi
authors: Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan.
authors: Akiko
authors: A
authors: Kitahashi
authors: Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan.
authors: Reo
authors: R
authors: Fukuda
authors: Department of Emergency and Critical Care Medicine, Nippon Medical School Tama Nagayama Hospital, Japan.
authors: Kyoko
authors: K
authors: Unemoto
authors: Department of Health Informatics and Policy, Tokyo Medical and Dental University, Graduate School of Medicine, Japan.
authors: Kiyohide
authors: K
authors: Fushimi
authors: Department of Clinical Epidemiology and Health Economics, School of Public Health, Graduate School of Medicine, The University of Tokyo, Japan.
authors: Hideo
authors: H
authors: Yasunaga
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000638:Amiodarone / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D004632:Emergency Medical Services / Q000379:methods; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality / Q000628:therapy*; D011744:Pyrimidinones / Q000627:therapeutic use*; D012189:Retrospective Studies; D014693:Ventricular Fibrillation / Q000188:drug therapy* / Q000401:mortality; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents; D011744:Pyrimidinones; C076259:nifekalant; D000638:Amiodarone
keywords: Cardiac arrhythmias and resuscitation science; Ventricular fibrillation; Ventricular tachycardia