Background: Cardiac mortality rates vary substantially between countries and ethnic groups. It is unclear, however, whether South Asian, Chinese, and white populations have a variable prognosis after acute myocardial infarction (AMI). To clarify this association, we compared mortality, use of revascularization procedures, and risk of recurrent AMI and hospitalization for heart failure between these ethnic groups in a universal-access healthcare system.
Methods and results: We used a population cohort study design using hospital administrative data linked to cardiac procedure registries from British Columbia and the Calgary Health Region Area in Alberta (1994 to 2003) to identify AMI cases. Patient ethnicity was categorized using validated surname algorithms. There were 2190 South Asian, 946 Chinese, and 38479 white patients with AMI identified. There was no significant difference in use of revascularization procedures between ethnic groups at 30 d and 1 year. Short-term (30-day) mortality was higher among Chinese relative to white patients (odds ratio, 1.23; 95% confidence interval, 1.02 to 1.48). There was no significant difference in 30-day mortality between South Asian and white patients. South Asian patients had a 35% lower relative risk of long-term mortality compared with white patients (hazard ratio, 0.65; 95% confidence interval, 0.57 to 0.72). There was no significant difference in long-term mortality between Chinese and white patients. Among AMI survivors, Chinese patients had a lower risk of recurrent AMI, whereas there was no difference between South Asian and white patients.
Conclusion: The ethnic groups studied have striking differences in outcomes after AMI, with South Asian patients having significantly lower long-term mortality after AMI.