Age-specific trends in the incidence and in-hospital mortality of acute myocardial infarction over 30 years in Japan — Report from the miyagi ami registry study —

Background: We are now facing rapid population aging in Japan, which will affect the actual situation of cardiovascular diseases. However, age-specific trends in the incidence and mortality of acute myocardial infarction (AMI) in Japan remain to be elucidated. Methods and Results: We enrolled a total of 27,220 AMI patients (male/female 19,818/7,402) in our Miyagi AMI Registry during the past 30 years. We divided them into 4 age groups (≤59, 60–69, 70–79 and ≥80 years) and examined the temporal trends in the incidence and in-hospital mortality of AMI during 3 decades (1985–1994, 1995–2004 and 2005–2014). Throughout the entire period, the incidence of AMI steadily increased in the younger group (≤59 years in both sexes), while in the elderly groups (≥70 years in both sexes), the incidence significantly decreased during the last decade (all P<0.01). In-hospital cardiac mortality significantly decreased during the first 2 decades in elderly groups of both sexes (all P<0.01), whereas no further improvement was noted in the last decade irrespective of age or sex, despite improved critical care of AMI. Conclusions: These results provide the novel findings that the incidence of AMI has been increasing in younger populations and decreasing in the elderly, and that improvement in the in-hospital mortality of AMI may have reached a plateau in all age groups in Japan.