Circadian, weekly, and seasonal mortality variations in out-of-hospital cardiac arrest in Japan: analysis from AMI-Kyoto Multicenter Risk Study database

• Published in: The American journal of emergency medicine Vol. 29; no. 9; pp. 1037 - 1043
• Main Authors: Nakanishi, Naohiko, MD, Nishizawa, Shinya, MD, Kitamura, Yohei, MD, Nakamura, Takeshi, MD, Matsumuro, Akiyoshi, MD, Sawada, Takahisa, MD, Matsubara, Hiroaki, MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.2011; Elsevier; Elsevier Limited
• Subjects: Aged; Aged, 80 and over; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cardiopulmonary resuscitation; Cardiovascular disease; Chi-Square Distribution; Circadian Rhythm; CPR; Databases, Factual; Emergency; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency medical care; Female; Heart attacks; Hospitals; Humans; Incidence; Intensive care medicine; Japan - epidemiology; Male; Medical sciences; Middle Aged; Mortality; Out-of-Hospital Cardiac Arrest - epidemiology; Out-of-Hospital Cardiac Arrest - mortality; Prospective Studies; Risk Factors; Seasonal variations; Seasons; Statistics, Nonparametric; Studies; Tachycardia, Ventricular - epidemiology; Tachycardia, Ventricular - mortality; Temperature; Time Factors; Ventricular Fibrillation - epidemiology; Ventricular Fibrillation - mortality; Asia; Japan; Cardiocirculatory arrest; Intensive care; Seasonal variation; Multicenter study; Mortality; Risk factor; Database; Cardiovascular disease; Out of hospital; Resuscitation
• ISSN: 0735-6757; 1532-8171
• DOI: 10.1016/j.ajem.2010.06.018

Abstract Background Several studies have reported circadian, weekly, and seasonal variations in the rates of out-of-hospital cardiac arrest (OHCA). However, variations in the mortality of OHCA are not well known. Methods and Results We investigated the 1396 consecutive cases of OHCA with cardiac etiology between October 2004 and September 2008. There were 2 peaks in the occurrence of OHCA in early morning and late evening. There was a weekly pattern with an increased incidence on Mondays. We found a significant seasonal variation in the frequency of events, with a maximum during winter. There was a trend of reduced mortality in warmest 3 months, especially among a subgroup of ventricular fibrillation/pulseless ventricular tachycardia with arrest witnessed. Conclusion The present analyses demonstrated circadian, weekly and seasonal variations in the occurrence, and a seasonal variation in mortality in OHCA. Changes in temperature might influence the severity of OHCA and change the rate of success of cardiopulmonary resuscitation.