Abstract 360: Clinical Characteristics and Outcome in Out-of-Cardiac Arrest Patients With Type A Aortic Dissection Diagnosed by Non-Contrast Computed Tomography

Background: Although type A aortic dissection (AAD) remains a life-threatening disease, the exact epidemiology of out-of-hospital cardiac arrest (OHCA) with AAD is unclear. It has been reported that the non-contrast computed tomography (CT) is useful for diagnosing AAD in patients whose hemodynamic status was unstable.

Aim: We evaluated the clinical features and outcome of OHCA patients with AAD diagnosed by non-contrast CT.

Methods: Between 2017 and 2022, we retrospectively collected Utstein-style data on non-traumatic adult OHCA patients transferred to our hospital and performed non-contrast full-body CT scan. We divided OHCA patients into 3 groups: patients with AAD diagnosed by CT (Group-AAD), patients with non-cardiac cause without AAD (Group-NC), and patients with cardiac cause (Group-C). The diagnostic criteria of AAD by CT were as follows: visible intimal flap; crescentic high attenuation hematoma; and inward shift of calcified intima. The clinical outcome was defined as return of spontaneous circulation (ROSC).

Results: Of the 1018 non-traumatic adult OHCA patients were registered during the study period, 1015 patients underwent non-contrast CT (Group-AAD, n=79; Group-NC, n=159; Group-C, n=779). The patients who achieved return of spontaneous circulation (ROSC) was 271 (26.8%). The proportion of patients who achieved ROSC in Group-AAD was significantly smaller than the other groups (Group-AAD 10.1%, Group-NC 27.7%, Group-C 28.3%, P=0.002). Multivariable logistic regression analysis revealed that patients with AAD diagnosed by CT independently predicted failure to achieve ROSC. The presence of witnessed arrest and initial shockable rhythm were significant indenpent predictors of achieving ROSC ( Table ).

Conclusion: OHCA patients with AAD diagnosed with CT were more difficult to obtain ROSC than patients with other cause.