Ethnicity and acute myocardial infarction: risk profile at presentation, access to hospital management, and outcome in Norway

M Abdelnoor,^1,2 J Eritsland,² C Brunborg,¹ S Halvorsen<sup>2

1</sup>Unit of Biostatistics and Epidemiology, ²Department of Cardiology, Oslo University Hospital Ullevaal, Oslo, Norway

Background: Previous studies in North America have shown ethnic variation in the presentation of acute myocardial infarction (AMI), and sex and racial differences in the management and outcome of AMI. In the present study, our aim was to investigate the risk profile of AMI for patients with minority background compared with indigenous Norwegians, at hospital presentation, and to investigate racial differences in hospital care and outcomes.
Patients and methods: A dual-design study was adopted: a cross-sectional study to examine ethnic differences of risk prevalence at hospital presentation and a cohort study to estimate access to angiography, percutaneous coronary intervention (PCI), and hospital and long-term mortality. From a study population of 3105 patients with AMI presenting at Oslo University Hospital between January 1, 2006 and December 31, 2007, we identified 147 cases of AMI in patients with minority background and selected a random sample of 588 indigenous Norwegians with AMI as controls. Prognostic and explanatory strategies were used in the analysis.
Results: Compared with indigenous Norwegians with AMI, AMI patients with minority background suffered their AMI 10 years younger, were generally male, were twice as likely to be smokers, three times as likely to have type 2 diabetes, had lower high-density lipoprotein levels. This group also had 50% less history of hypertension. In terms of hospital care, AMI patients with minority background had shorter times from onset of symptoms to PCI and the same frequency of access to angiography and acute PCI as indigenous Norwegians when adjusting for the confounding effect of age, sex, and nature of myocardial infarction with or without ST elevation.
Conclusion: At presentation to hospital, patients with minority background had a higher risk profile and a shorter time from onset of symptoms to admission to catheterization laboratory than indigenous Norwegians, but the same access to angiography and acute PCI during hospitalization.

Keywords: ethnicity, myocardial infarction, presentation, management, outcome