Acute myocardial infarction in Fukushima area of Japan.

Although acute myocardial infarction (AMI) is the most serious coronary disease, the background of its onset and the mortality are not fully understood, especially in Japan. From June 1999 to May 2005, we mailed an annual questionnaire to eighteen hospitals in which emergency cardiac catheterization and percutaneous coronary intervention (PCI) were available in the Fukushima area of Japan. A total of 1,590 patients were included. The onset time of AMI had two peaks, i.e., from 9:00 AM to 10:00 AM and 9:00 PM to 10:00 PM. As for reperfusion therapy, four groups were analyzed, the non-reperfusion therapy group (Group N, n = 233), thrombolysis alone group (Group T, n = 80), PCI without thrombolysis group (Group P, n = 1106), and PCI with thrombolysis group (Group TP, n = 151). The in-hospital mortality rate was significantly reduced in Group P (8.4%) compared with that in Group N (33.0%, p < 0.01) and Group T (18.8%, p < 0.01). However, the in-hospital mortality in Group P did not differ from that in Group TP (9.9%). The in-hospital mortality was analyzed by the logistic regression analysis among age, arrival time after onset, peak creatine kinase (CK) values, coronary risk factors, reperfusion therapy, PCI, and thrombolysis. There were significant differences in age (P < 0.01), peak CK values (p < 0.01), hypertension (p < 0.05), and diabetes mellitus (p < 0.01). These results suggest that the onset of AMI may be partly related to human biorhythms, and that PCI would be effective in reducing the in-hospital mortality.