Nationwide Trends in the Incidence of Acute Myocardial Infarction in Australia, 1993–2010

Although most of the additional increases in coronary heart disease morbidity and mortality are estimated to occur outside developed regions such as North America and Europe, few nationwide studies have been published of acute myocardial infarction (MI) epidemiology from other regions. We thus sought to expand the global data regarding MI trends. Nationwide trends of incident MI, ST-segment elevation MI (STEMI), and non–ST-segment MI (non-STEMI) were analyzed during a 17-year period in Australia. We identified 714,262 hospitalizations for MI from 1993 to 2010, representing 331,871,389 person-years. During the study period, the age- and gender-adjusted incidence of all MIs increased from 215 to 251 cases per 100,000 person-years, a relative increase of 76% (p <0.0001 for trend). The adjusted incidence of STEMI decreased from 147 to 70 cases per 100,000 person-years, a relative decrease of 30% (p <0.0001 for trend). In contrast, the adjusted incidence of non-STEMI increased from 67 to 182 cases per 100,000 person-years, a relative increase of 315% (p <0.0001 for trend). Age-specific analyses suggested that statistically significant increases in MI incidence were present in those aged <50 and ≥80 years. In conclusion, although it has previously been suggested that declining trends in MI incidence in North American and European reports might be generalizable given the seemingly consistent observations thus far, the present results highlight the possibility that other global populations might have less favorable trends. The incidence of MI in Australia might not be decreasing as rapidly as that seen in other regions and requires additional exploration.