Ethnicity Is Associated With Differing Presentation and Outcomes of Patients Undergoing Aortic Valve Replacement for Calcific Aortic Stenosis in Aotearoa New Zealand

AIM: Surgical aortic valve replacement (SAVR) has been the gold standard for treatment of severe symptomatic aortic stenosis (AS) for decades. We examined whether ethnic differences exist in the presentation and outcomes of patients undergoing aortic valve replacement (AVR) for AS in New Zealand. METHODS: Patients of New Zealand European, Māori, and Pacific Island ethnicities undergoing SAVR with or without other procedures in New Zealand public hospitals from 2017 to 2019 were included. Major postoperative outcomes were compared between ethnic groups, with 30-day mortality being the primary outcome. RESULTS: A total of 1,175 patients were included: 1,085 European, 50 Māori, and 40 Pacific. The mean age was 71.1±9.4 years, and men accounted for more than half of all patients (69.9%). Māori (64.7±9.4 years) and Pacific (65.4±10.1 years) patients were younger when undergoing SAVR compared with European patients (71.7±9.2; analysis of variance p<0.001). Māori and Pacific patients had a higher prevalence of diabetes, poorer renal function, and worse left ventricular function; 30-day mortality was higher in Māori and Pacific compared with European patients (6% and 10% vs 2.4%, respectively; Fisher's exact test p=0.011), with odds ratio of 3.06 (95% confidence interval [CI] 0.88-10.66) for Māori patients after adjustment for EuroSCORE II and odds ratio of 5.23 (95% CI 1.79-16.07) for Pacific patients. CONCLUSIONS: There are significant differences in presentation and outcomes of patients undergoing AVR in New Zealand. Māori and Pacific patients undergo SAVR at a younger age, have more preoperative comorbidities, and have higher rates of 30-day mortality than European patients.