Incidence and survival rate of bystander-witnessed out-of-hospital cardiac arrest with cardiac etiology in Osaka, Japan: a population-based study according to the Utstein style

Purpose: To clarify the incidence and survival rate of bystander-witnessed out-of-hospital cardiac arrests (OHCA) with cardiac etiology in Osaka Prefecture, Japan, with a population of nearly 9 million according to the Utstein style. Subjects and Methods: 5047 consecutive OHCA cases were treated by ambulance personnel during the 12-month period starting since 1 May 1998. 974 cases were considered to be bystander-witnessed OHCA with cardiac etiology and analyzed using the Utstein style. Results: Of the 974 cases (100%), 50 cases (5.1%) survived after 1 month and 28 (2.9%) of them after 1 year. The Ventricular fibrillation (VF)/ventricular tachycardia (VT) group comprised 164 (16.8%) cases and there were statistically differences between the two groups as below (the VF/VT group vs. the non-VF/VT group): gender (male: 76.8 vs. 60.7%), age (61.7±14.7 vs. 68.7±17.1), history of ischemic heart disease (IHD) (30.5 vs. 15.3%), performance rate of bystander cardiopulmonary resuscitation (CPR) (34.1 vs. 21.4%) and time interval between receipt of an emergency call and arrival at the scene (5.5±2.9 vs. 6.0±2.9 min). Conclusion: The incidence of bystander-witnessed (OHCA) with cardiac etiology and VF or VT were remarkably low compared with those reported by other studies conducted in some areas of Europe or the USA. Objectivo: Clarificar a incidência e taxa de sobrevida das paragens cardı́acas presenciadas, fora do Hospital (OHAC) de etiologia cardı́aca, na comarca de Osaka, Japão com uma população de 9 milhões, de acordo com o modelo de Utstein. Material e métodos: o pessoal das ambulâncias tratou 5047 OHCA num perı́odo de 12 meses com inı́cio a 1 de Maio de 1998. Desses 974 foram considerados OHCA presenciados e com etiologia cardı́aca e analisados com o modelo de Utstein. Resultados: dos 974 casos (100%), sobreviveram um mês 50 (5.1%) e ao fim de um ano estavam vivos 28 (2.9%). O grupo da fibrilhação ventricular (VF) e da taquicardia ventricular (VT) incluiu 164 casos (16.8%) e havia diferenças significativas entre os dois grupos (grupo VF/VT e grupo não VF/VT), no que se refere ao: sexo (masculino 76.8% vs. 60.7%), idade (61.7±14.7 vs. 68.7±17.1), história de doença isquémica coronária (HID) (30.5 vs. 15.3%), desempenho das testemunhas (CPR) (34.1 vs. 21.4%) e tempo decorrido da recepção da chamada de ajuda à chegada ao local (5.5±2.9 vs. 6.0±2.9 min.). Conclusões: a incidência de paragens cardı́acas de etiologia cardı&#x0