Age-related differences in clinical characteristics, early outcomes and cardiac management of acute myocardial infarction in Japan: Lessons from the Tokai Acute Myocardial Infarction Study (TAMIS)

Recent data suggest substantial variations in the treatment strategies for patients with acute myocardial infarction (AMI) based on age. This study aimed to compare the management and early outcomes of AMI across age groups in Japan. Data from 13 acute care hospitals that were included in the Tokai Acute Myocardial Infarction Study sample were used. This is a retrospective study of all patients admitted to the hospitals with the diagnosis of AMI from 1995–1997. We abstracted the baseline and procedural characteristics from detailed chart reviews. Patients were stratified into four age categories: up to 64; 65–74; 75–84; and 85 or more years of age. A total of 966 patients were aged up to 64 years, 608 were 65–74 years, 365 were 75–84 years, and 79 were 85 or more years. The rates at which the treadmill test, coronary angiography and percutaneous coronary intervention were performed decreased with advancing age (−14%, P < 0.01; −55%, P < 0.01; and −42%, P < 0.01, respectively, for the up to 64-year-old vs 85-year-old or more groups). Thrombolytic therapy was less often prescribed in the older groups (P < 0.01). At discharge, aspirin, β-blockers, angiotensin-converting enzyme inhibitors, nitrates, calcium antagonists, and anti-hyperlipidemics were prescribed less often in the older groups (P < 0.01, <0.05, <0.01, <0.01, <0.01, <0.01, respectively), while diuretics were prescribed more often in the older groups (P < 0.01). Our results suggest that fewer elderly patients were under-treated and had a significantly higher risk of in-hospital mortality.