Abstract 90: Circadian Variation in Out-of-Hospital Cardiac Arrests in a Nationwide Japanese Patient Population: A Difference Between Survivors and Nonsurvivors
Background: It is well known that acute cardiovascular events and sudden cardiac death occur most frequently in the morning. This study aimed to determine whether there is a difference of circadian variation between survivors and nonsurvivors in the presentation of all-Japan cohort of patients with out-of-hospital cardiac arrests.
Methods: We referred a database of a prospective, nationwide, population-based registry of out-of-hospital cardiac arrests that is conducted by the Fire and Disaster Management Agency of Japan between April 2006 and December 2009. The records are based on the standardized Utstein style. Patients who had sudden collapse witnessed by family members, friends, or bystanders of the public and who received cardiopulmonary resuscitation (CPR) in accordance with protocol of guideline 2005 were enrolled. We categorized patients into two groups: survivors for 30 days and more after cardiac arrest and nonsurvivors who died of cardiac arrest. We assessed the incidence of the cardiac arrest as hourly data (i.e., circadian variation).
Results: A total of 411,562 patients were registered nationwide and 92,492 patients had cardiogenic out-of-hospital cardiac arrests witnessed by bystanders. Of the patients, 1,817 patients were excluded because exact time of collapse or certain age was not determined. Finally, 90,675 patients were enrolled for assessment. Of the patients, 9,681 patients (10.7%) were successfully resuscitated and survived and 80,994 patients (89.3%) died. Survivors had a large single circadian rhythm in the morning (8:00-9:00). Men had more apparent circadian variation than women in the survivors. In contrast, nonsurvivors had a circadian rhythm with two zeniths in the morning (8:00-9:00) and evening (18:00-19:00). No difference of gender was found in the nonsurvivors.
Conclusions: There exists a different circadian variation of out-of-hospital cardiac arrests between survivors and nonsurvivors, particularly in men. In emergency cardiovascular care, the management in the evening is also important to improve the survival rate.
- © 2011 by American Heart Association, Inc.