Association between shockable rhythm conversion and outcomes in patients with out-of-hospital cardiac arrest and initial non-shockable rhythm, according to the cause of cardiac arrest

Resuscitation. 2019 Sep:142:144-152. doi: 10.1016/j.resuscitation.2019.07.025. Epub 2019 Aug 1.

Abstract

Objective: Conversion to shockable rhythm from an initial non-shockable rhythm is associated with good neurologic prognoses in patients with out-of-hospital cardiac arrest (OHCA). We aimed to investigate whether conversion to shockable rhythm has an association with good neurologic outcomes, according to the etiology of cardiac arrest.

Methods: We conducted a nationwide, population-based, cohort study using the OHCA data from the Korea Centers for Disease Control and Prevention database in 2012-2016. We included patients with OHCA and an initial non-shockable rhythm. The primary outcome was good neurologic outcome at discharge, etiologies of arrest were categorized to medical, non-medical cause. We analyzed the effect of conversion to a shockable rhythm on outcome according to causes of cardiac arrest using multiple regression analysis.

Results: Of 114,628 patients with an initial non-shockable rhythm, 25,042 (21.8%) experienced conversion to a shockable rhythm; 83,437 (72.8%) had medical causes and 31,191(27.2%) had non-medical causes. In all patients with OHCA and initial non-shockable rhythm, adjusted odds ratio (OR) of conversion for good neurologic outcome was 2.051 (95% confidence interval [CI] 1.181-2.297). The medical cause group showed an adjusted OR 1.789 (95% CI 1.586-2.019) of conversion for good neurologic outcome. In non-medical cause group, the adjusted OR of conversion was 0.644 (95% CI 0.372-1.114).

Conclusion: Conversion to shockable rhythm had an association with good neurologic outcome in patients with OHCA with initial non-shockable rhythms, especially due to cardiac cause. However, rhythm conversion was not associated with better outcome in patients with non-medical causes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Cardiopulmonary Resuscitation* / methods
  • Cardiopulmonary Resuscitation* / statistics & numerical data
  • Electric Countershock / methods
  • Emergency Medical Services / statistics & numerical data
  • Female
  • Heart Diseases / complications*
  • Heart Rate*
  • Humans
  • Male
  • Nervous System Diseases* / diagnosis
  • Nervous System Diseases* / etiology
  • Out-of-Hospital Cardiac Arrest* / epidemiology
  • Out-of-Hospital Cardiac Arrest* / etiology
  • Out-of-Hospital Cardiac Arrest* / physiopathology
  • Out-of-Hospital Cardiac Arrest* / therapy
  • Prognosis
  • Registries
  • Republic of Korea / epidemiology
  • Time Factors