Population-based incidence and outcomes of acute aortic dissection in Japan

Abstract

Abstract Background The population-based incidence and outcomes of acute aortic dissection (AAD) are still unknown because some patients are already dead on arrival at the hospital, and the accurate diagnosis of AAD is difficult due to the low autopsy rate for patients with cardiopulmonary arrest outside of the hospital. We performed a population-based review of all patients with AAD in a well-defined geographical area in the southern part of Japan between 2016 and 2018. Methods Data of all patients with AAD at our Hospital, which performs medical care for 120,000 residents, were collected retrospectively. The emergency medical service is dedicated to the transfer of all patients in this area to the MPNH. For all patients who were dead on arrival, the diagnosis of AAD was made by autopsy imaging (AI) using computed tomography. The age-adjusted incidence and mortality per 100,000 population were calculated using the Japanese population distribution model in 2015. Results The total incidence of AAD was 79 (type A: 64.5%, n=51). Of those, 60.8% (31/51) of patients with type A and 21.4% (6/28) with type B were dead on arrival and diagnosed by AI. The 30-day mortality rates after the onset of AAD were 74.5% (38/51) in type A and 25.0% (7/28) in type B. Excluding the dead-on-arrival patients, the 30-day mortality rates were 35.0% (7/20) in type A and 4.5% (1/22) in type B. The age-adjusted incidence and mortality of AAD per 100,000 inhabitants were 17.3 (type A: 11.3, type B: 6.0) and 9.6 (type A: 8.4, type B: 1.2), respectively. Both values were significantly higher in men than in women. Conclusions The population-based survey of emergency medical care for AAD showed that the age-adjusted incidence of AAD was two-fold higher than in previous reports, and the actual mortality rates after AAD onset were markedly higher due to the high incidence of dead-on-arrival. Funding Acknowledgement Type of funding sources: None. Representative CT images of type A AAD