Coronary risk factors and related characteristics of acute myocardial infarction (AMI) were studied in patients with AMI (fitst time occurrence) in the Aomori area where the mortality from ischemic heart disease and stroke were higher than in the rest of Japan.
Subjects were 512 patients (364 male and 148 female) with AMI, aged 21 to 89 years old who were admitted to Aomori prefectural central hospital between April 1981 and March 1994.
Items surveyed included 1. sex, 2. type of angina pectoris prior to AMI, 3. number of patients with AMI per year, 4. circadian variation in the frequency of AMI onset, 5. variation in the frequency of AMI onset during a year, 6. how soon the patients entered the hospital after the onset of AMI, 7. activity conditions at the onset of AMI, 8. coronary risk factors : a) smoking, b) hypertension, c) aortic arch calcification in chest X-P, d) diabetes mellitus, e) hyper-cholesterolemia, f) obesity, g) hyperuricemia, h) renal function disorder, i) family history, j) cerebro-vascular disease, k) total number of coronary risk factors in patients with AMI in each hemodynamic subset of Forrester's classification.
Results should that two specific factors related to AMI exist in AMI in the Aomori area, Japan : 1. onset of AMI was concentrated in the winter season (cold stress), 2. ratio of presence of hypertension was higher than in rest Japan. It appears that counter-measures directed at the two factors may decrease mortality from ischemic heart disease in the Aomori area.

View full abstract

The proportional rate of ischemic heart disease (IHD) in sudden death cases was estimated from surveys in Niigata prefecture of death certificates and death registration for new cases. Death from cardiovascular diseases (OCD) other than acute myocardial infarction (AMI) were classified into three groups according to medical history : cases which had suffered from IHD (OCD (IHD+)), cases whose histoy on IHD was unclear (OCD (IHD ?)), and cases which most likely have not suffered from IHD (OCD (IHD-)). The lower level of estimates was set at the rate for death from either AMI or OCD (IHD+), and the upper level, the rate for deaths including OCD (IHD ?). Based upon two registration surveys where the diagnosis could be considered accurate as all cases were attended by cardiologists, the proportional rate of IHD was 41 to 86 % (≥15 years old) and 36 to 87 % (15 to 65 years old) of total cardiac sudden death for death within 24 hours from the onset, and 32 to 86 % (≥ 15 years old) and 33 to 81 % (15 to 65 years old) for death within one hour. When these values were interpolated into all sudden death cases derived from the death certificate survey, the proportional rate was estimated to be 28 to 59 % (≥ 15 years old) and 23 to 56 % (15 to 65 years old) for death within 24 hours, and 25 to 68 % (≥ 15 years old) and 26 to 62 % (15 to 65 years old) for death within one hour.
When all deaths from either AMI or OCD (IHD+) were treated as IHD cases, the proportional rates of IHD from the death certificate survey and the registration survey were approximately equal. However for deaths within one hour, deaths from AMI were lower and deaths from IHD were greater in the registration survey than in the death certificate survey. This may be a reflection of a paradoxical phenomenon that a high degree of diagnostic accuracy causes a decrease in the number of the cases identified to have died from definite AMI as the time course until death becomes shorter.

View full abstract

Medical and police records were examined for the subjects who have possibilities to have experienced sudden death (SD) by applying a selection criteria to death certificates in Suita city, population 341, 000, for deaths in 1992. Most of the previous population based surveys of SD in Japan have been based solely on examination of death certificates, and the details of population based sudden death has not been clear in Japan, especially in urban areas.
Subjects selected had underlying cause of death as heart disease, and whose time until death from onset of the direct cause of death as shown on the death certificate was less than 24 hours or unknown. 'Sudden death' Was defined as the death which occurred within 24 hours of an acute onset of symptoms. Categorization for myocardial infarction (MI) was made with WHO MONICA criteria.
Of the 211 cases selected from 779 total deaths aged 20 to 74 years, 198 (93.8 %) cases could be examined, and 76 were categorized as SD, which was 9.9 % of all the deaths. Incidence was 0.32 per 1000 population per year, 0.45 for men and 0.20 for women. As to cause of death, 46 (61 %) were considered as SD of unknown origin. For the rest, 17 (57 %) were considered as MI, 6 (20 %) stroke, and 1 (3 %) other cardiovascular disease, totalling 24 (80 %) as cardiovascular in origin. Of those categorized as SD of unknown origin, 15 (33 %) died within one hour of onset, and the cause appeared to be cardiac. Of the SDs, 56 % had apparent histories of hypertension, hyperlipidemia, diabetes, MI or stroke. Also, 11 (20 %) of SDs had suspected alcohol abuse, and all of them were men.
In conclusion, control of cardiovascular risk factors, and alcohol abuse mainly in men seems to be important to prevent SD.

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract

[in Japanese]

View full abstract