Ethnicity and revascularisation following acute coronary syndromes: a 5-year cohort study (ANZACS-QI-3).

Background: Prior studies have reported higher rates of coronary revascularisation in European compared with Maori and Pacific patients. Our aim was to define the current variation by ethnicity in investigation, revascularisation and pharmacotherapy after admission with an acute coronary syndrome (ACS).

Methods: Data from consecutive New Zealand residents <80 years of age admitted to the Middlemore Hospital coronary care unit with ACS (2007 to 2012) were collected prospectively.

Results: Of 2666 ACS patients <80y, 51.5% were European/Other, 14.2% Maori, 16.0% Pacific, 14.8% Indian, and 3.5% Asian. Cardiac risk factors and comorbidity varied markedly by ethnicity. The overall coronary angiography rate was high (89%). After adjustment for clinical factors which influence the decision to perform angiography, European/Other patients were about 5% more likely than Maori and Pacific patients to have angiography. Overall revascularisation was highest in Asian, Indian and European/Other (76.1%, 69.1% and 68.6%), and lower in Maori and Pacific patients (58.2% and 52.9%). Non-obstructive coronary disease was more common in Maori and Pacific (20.6 and 18.6%, respectively), than in European/Other, Indian and Asian patients (13.3%, 8.7% and 6.1%). After adjustment, Maori, Indian and Asian patients were as likely to receive revascularisation as European/Others, but revascularisation in Pacific patients was 13% lower. Discharge prescribing of triple preventive therapy was uniformly high across ethnic groups (overall 91%).

Conclusions: There is a small unexplained variation in angiography rates across ethnic groups. Much of the observed variation in revascularisation may be due to differences in the coronary artery disease phenotype.