Myocardial infarction incidence and survival by ethnic group: Scottish Health and Ethnicity Linkage retrospective cohort study

OBJECTIVE: Inequalities in coronary heart disease mortality by country of birth are large and poorly understood. However, these data misclassify UK-born minority ethnic groups and provide little detail on whether excess risk is due to increased incidence, poorer survival or both. DESIGN: Retrospective cohort study. SETTING: General resident population of Scotland. PARTICIPANTS: All those residing in Scotland during the 2001 Census were eligible for inclusion: 2 972 120 people were included in the analysis. The number still residing in Scotland at the end of the study in 2008 is not known. PRIMARY AND SECONDARY OUTCOME MEASURES: As specified in the analysis plan, the primary outcome measures were first occurrence of admission or death due to myocardial infarction and time to event. There were no secondary outcome measures. RESULTS: Acute myocardial infarction (AMI) incidence risk ratios (95% CIs) relative to white Scottish populations (100) were highest among Pakistani men (164.1 (142.2 to 189.2)) and women (153.7 (120.5, 196.1)) and lowest for men and women of Chinese (39.5 (27.1 to 57.6) and 59.1 (38.6 to 90.7)), other white British (77 (74.2 to 79.8) and 72.2 (69.0 to 75.5)) and other white (83.1 (75.9 to 91.0) and 79.9 (71.5 to 89.3)) ethnic groups. Adjustment for educational qualification did not eliminate these differences. Cardiac intervention uptake was similar across most ethnic groups. Compared to white Scottish, 28-day survival did not differ by ethnicity, except in Pakistanis where it was better, particularly in women (0.44 (0.25 to 0.78)), a difference not removed by adjustment for education, travel time to hospital or cardiac intervention uptake. CONCLUSIONS: Pakistanis have the highest incidence of AMI in Scotland, a country renowned for internationally high cardiovascular disease rates. In contrast, survival is similar or better in minority ethnic groups. Clinical care and policy should focus on reducing incidence among Pakistanis through more aggressive prevention.