Ethnic differences in incidence and outcomes of acute aortic syndromes in the Midland region of New Zealand.

Abstract

Disparities in cardiovascular disease according to socioeconomic factors and ethnicity are a global issue. The indigenous Māori population of New Zealand is not exempt. The aims of the present study were to assess whether ethnic disparities exist in the presentation and outcomes of acute aortic syndrome (AAS), including aortic dissection, intramural hematoma, and penetrating aortic ulcer, in New Zealand. A retrospective observational cohort study of consecutive AAS patients presenting to a tertiary referral center covering the Midland region of New Zealand (population, 816,900; 23.3% Māori) during a 10-year period was completed (2010-2020). Data were assessed by ethnicity (Māori vs non-Māori) and Stanford classification of AAS. The incidence of disease, 30-day mortality, and long-term all-cause and aortic-related mortality were recorded and assessed using logistic regression and Cox proportional hazards models. A total of 250 patients had presented with AAS (Māori, 92 [36.8%]; type A, 144 [57.6%]). The age-standardized rates of AAS were higher in Māori than in non-Māori patients (6.9/100,000 person-years vs 2.0/100,000 person-years; risk ratio, 3.56; 95% confidence interval, 1.50-8.53; P = .002). Māori patients had presented at a younger age for both type A (age, 54.4 ± 12 years vs 66.0 ± 13.2 years; P < .001) and type B (age, 61.3 ± 10.2 years vs 68.8 ± 13.7 years; P = .005) AAS. Mortality at 30 days was higher for those with type A than for those with type B AAS (33.3% vs 13.2%; P < .001) but did not differ by ethnicity in our cohort. On multivariate analysis, no differences were found in 30-day or long-term survival when stratified by ethnicity. The results from the present study have demonstrated that ethnic disparities in AAS exist in New Zealand, with Māori presenting at a younger age and with a greater incidence compared with other ethnicities. Whether this disparity is related to socioeconomic factors, access to preventive care, or other factors remains to be elucidated. Despite these differences in disease presentation, the survival outcomes when stratified by ethnicity were comparable in the present cohort.