Incidence and long-term prognosis of initial stroke and acute myocardial infarction in Okinawa, Japan

We performed a cross-sectional survey of the incidence of stroke and acute myocardial infarction (AMI) in Okinawa, Japan, with a census population of about 1.2 million. A total of 3,644 cases of first-ever stroke and 898 case s of initial AMI were detected. The age-adjusted annual incidence rate of s troke was 105 per 100,000 of the standard population of Japan based on cens us population taken in 1985, and that of AMI was 26 per 100,000. The case-f atality rate of stroke within 28 days of onset was 12.8%, and that of AMI w as 22.2%. Of the stroke cases, 51.4% were diagnosed as brain infarctions, 3 8.7% as brain hemorrhages, and 9.3% as subarachnoid hemorrhages. The diagno ses of stroke subtypes were confirmed by computed tomography or magnetic re sonance imaging in 98.4% of all stroke cases. The long-term prognosis of pa tients with stroke and AMI was studied by examining their 10-yr survival ra tes (follow-up rate 89.8%). The cumulative survival rate was 38.2% in brain infarction cases, 40.4% in brain hemorrhage cases, and 38.2% in AMI cases. The 50% reduction of survival had occurred at 2,880 days after onset in br ain infarction cases, at 2,764 days in brain hemorrhage cases, and at 2,658 days in AMI cases. In Okinawa, the incidence rate of AMI was still conside rably lower than that in the Western population, and the rate of stroke was similar to that in the Western population. The ten year survival rates wer e quite;lite similar in AMI and stroke, and both were unexpectedly high. (H ypertens Res 2000; 23: 127-135).