Ethnic Disparities in CT Aortography Use for Diagnosing Acute Aortic Syndrome

To determine whether CT aortography was performed in proportion to patient risk for acute aortic syndrome (AAS) and incidence of AAS for different ethnic groups.

All atraumatic thoracic aorta CT aortographic examinations performed in adults (age > 15 years) suspected of having AAS between January 2009 and December 2019 at Auckland City Hospital (New Zealand) were included. Patients were risk stratified using the aortic dissection detection risk score (ADD-RS). The primary outcomes were the ratio of CT aortography rates to rates of positive CT aortographic examinations and the incidence of AAS. Population census data were used to determine age-standardized incidence of AAS in the emergency department (ED).

In total, 1646 CT aortographic examinations were performed in 1543 patients (mean age, 62 years ± 16 [SD]; 877 male patients). Māori (34% [68 of 203]) and Pacific Islanders (35% [80 of 229]) were more likely to be at high risk of AAS (ADD-RS > 1) compared with patients from other ethnic groups (25% [308 of 1214]); in the ED catchment population, age-standardized AAS incidence was significantly higher in Māori (6.9 per 100 000 person-years [95% CI: 4.3, 10.4]) and Pacific Islanders (5.3 [95% CI: 3.4, 7.8]) than in other ethnic groups (2.3 [95% CI: 1.8, 2.8]). Despite this higher incidence, disproportionately fewer CT aortographic examinations were requested in the ED for Māori (9.2 CT aortographic examinations per AAS diagnosis) and Pacific Islanders (9.2 CT aortographic examinations per AAS diagnosis) compared with other ethnic groups (13.8 CT aortographic examinations per AAS diagnosis).

Māori and Pacific Islanders were at disproportionately higher risk of AAS but had fewer requested CT aortographic examinations compared with other ethnic groups. This increased risk of AAS in Pacific Islander and indigenous Māori patients should be considered by clinicians when investigating AAS.Keywords: Ethnicity, Māori, Pacific Islander, Aortic Dissection Detection Risk Score, Acute Aortic Syndrome, Aortic Dissection, CT Angiography Supplemental material is available for this article. © RSNA, 2022.