LAUSR

Acute aortic dissection (AAD) is a life-threatening condition associated with high morbidity and mortality rates, and is reported to have a 1–2% fatality rate per hour after onset. Therefore, many cases with AAD are considered to be included in patients with out-of-hospital cardiopulmonary arrest (OHCPA). However at this time, there is a lack of documentation of these cases. In this study, we investigated the characteristics of Stanford type A AAD (TAAD) cases between OHCPA cases and survival cases using acute phase CT. An acute phase CT scanning was performed on consecutive patients with OHCPA transported to our hospital in order to estimate the causes of cardiopulmonary arrest (CPA). Based on our emergency outpatient databases, we retrospectively reviewed the acute phase CT findings of OHCPA TAAD cases and survival TAAD cases diagnosed at our hospital during the same period. Of 1,011 consecutive patients with OHCPA, except for exogenous death from 1 January 2015 to 31 December 2017, 934 patients underwent CT examination in the acute phase. Based on the clinical course and CT findings, 71 of the 934 patients (7.6%) were diagnosed with AAD. Out of 71 AAD patients, 66 were TAAD patients, and all of these patients were enrolled in the OHCPA group. On the other hand, 41 patients were registered as the survival group during the same period. These patients were diagnosed as TAAD and were admitted to our hospital without falling into CPA. Increased Age (78±8 years old vs 69±13 years old, P<0.01), visible intimal flap (63.6% vs 41.5%, P=0.043), bloody pericardial effusion (72.7% vs 26.8%, P<0.01), hemothorax (24.2% vs 0%, P<0.01) were significant in patients with the OHCPA group compared with the survival group. In addition, 56 patients with OHCPA (84.8%) had at least one of massive bloody pericardial effusion or massive hemothorax. Using multivariate logistic regression analysis, increased age and bloody pericardial effusion were both found to be independent factors related to OHCPA. In this study, it is thought that the main characteristics of the CT findings with OHCPA due to TAAD are a rupture of the aorta into the pericardial cavity or thoracic cavity.