Medium-term prognosis of young Japanese adults having acute myocardial infarction.

BACKGROUND Data on the medium- and long-term prognosis of young Japanese patients with acute myocardial infarction (AMI) are still lacking. METHODS AND RESULTS In the present study, 1,458 AMI patients were enrolled in the AMI-Kyoto Multi-Center Risk Study between January 2000 and December 2003. Of these, clinical characteristics and medium-term prognosis were retrospectively compared in 21 young patients < 40 years (young group), and 190 non-young patients 60-70 years old (non-young group) who could be followed after hospital discharge. The young group was all male and had higher prevalence of current smoking and greater body mass index, but previous myocardial infarction (MI) and hypertension were more prevalent in the non-young group. The young group had a higher prevalence of single-vessel disease and a lesser incidence of left circumflex coronary artery as the culprit lesion. The acquisition rates of Thrombolysis In Myocardial Infarction 3 flow after primary percutaneous coronary intervention did not differ between the 2 groups, but the data of maximal creatine kinase was significantly higher in the young group. During the follow-up period (average 2.42 years for young, 2.37 years for non-young), survival and event-free survival rates and incidence of major adverse cardiac events (MACE) did not differ between the 2 groups. The predictor of MACE during follow-up period was the presence of multivessel disease in the young group, whereas the presence of multivessel disease, history of previous MI and longer hospitalization were the predictors of MACE in the non-young group. CONCLUSIONS These results suggest that the medium-term prognosis in young AMI patients is comparable to that of non-young AMI patients in Japan.