Relation of socioeconomic position to the case fatality, prognosis and treatment of myocardial infarction events; the FINMONICA MI Register Study.

OBJECTIVE: To examine socioeconomic differences in case fatality and prognosis of myocardial infarction (MI) events, and to estimate the contributions of incidence and case fatality to socioeconomic differences in coronary heart disease (CHD) mortality. DESIGN: A population-based MI register study. METHODS: The FINMONICA MI Register recorded all MI events among persons aged 35-64 years in three areas of Finland during 1983-1992. A record linkage of the MI Register data with the files of Statistics Finland was performed to obtain information on socioeconomic indicators for each individual registered. First MI events (n=8427) were included in the analyses. MAIN RESULTS: The adjusted risk ratio of prehospital coronary death was 2.11 (95% CI 1.82, 2.46) among men and 1.68 (1.14, 2.48) among women with low income compared with those with high income. Even among persons hospitalised alive the risk of death during the next 12 months was markedly higher in the low income group than in the high income group. Case fatality explained 51% of the CHD mortality difference between the low and the high income groups among men and 38% among women. Incidence contributed 49% and 62%, respectively. CONCLUSIONS: Considerable socioeconomic differences were observed in the case fatality of first coronary events both before hospitalisation and among patients hospitalised alive. Case fatality explained a half of the CHD mortality difference between the low and the high income groups among men and more than a third among women.

Gender differences in recurrent coronary events; the FINMONICA MI register.

BACKGROUND: Male gender is an established risk factor for first myocardial infarction, but some studies have suggested that among myocardial infarction survivors, women fare worse than men. Therefore, we examined the long-term prognosis of incident myocardial infarction survivors in a large, population-based MI register, addressing gender differences in mortality as well as the number of events and time intervals between recurrent events. METHODS AND RESULTS: Study subjects included 4900 men and women, aged 25-64 years, with definite or probable first myocardial infarctions who were alive 28 days after the onset of symptoms. At first myocardial infarction, women were older and more likely to be hypertensive or diabetic than men, and had a greater proportion of probable vs definite events. After adjustment for age and geographic region, men had 1.74 times the risk of fatal coronary heart disease relative to women (hazard ratio=1.63 and 1.55 for cardiovascular disease and all-cause mortality, respectively) over an average of 5.9 years of follow-up. Number and time intervals between any recurrent event--fatal and non-fatal--did not differ by gender. CONCLUSION: These data suggest that men are far more likely to have a fatal recurrent event than women despite comparable numbers of events.

Relationship of socioeconomic status to the incidence and prehospital, 28-day, and 1-year mortality rates of acute coronary events in the FINMONICA myocardial infarction register study.

BACKGROUND: Low socioeconomic status (SES) is associated with increased coronary heart disease mortality rates. There are, however, very little data on the relation of SES to the incidence, recurrence, and prognosis of myocardial infarction (MI) events. METHODS AND RESULTS: The FINMONICA MI Register recorded detailed information on all MI events among men and women aged 35 to 64 years in 3 areas of Finland during the period of 1983 to 1992. We carried out a record linkage of the MI register data with files of Statistics Finland to obtain information on indicators of SES, such as taxable income and education, for each individual who is registered. In the analyses, income was grouped into 3 categories (low, middle, and high), and education was grouped into 2 categories (basic and secondary or higher). Among men with their first MI event (n=6485), the adjusted incidence rate ratios were 1.67 (95% CI 1.57 to 1.78) and 1.84 (95% CI 1.73 to 1.95) in the low- and middle-income categories compared with the high-income category. For 28-day mortality rates, the corresponding rate ratios were 3.18 (95% CI 2.82 to 3.58) and 2.33 (95% CI 2.03 to 2.68). Significant differentials were observed for prehospital mortality rates, and they remained similar up to 1 year after the MI. Findings among the women were consistent with those among the men. CONCLUSIONS: The excess coronary heart disease mortality and morbidity rates among persons with low SES are considerable in Finland. To bring the mortality rates of low- and middle-SES groups down to the level of that of the high-SES group constitutes a major public health challenge.

The validity of the routine mortality statistics on coronary heart disease in Finland: comparison with the FINMONICA MI register data for the years 1983-1992. Finnish multinational MONItoring of trends and determinants in CArdiovascular disease.

We compared the diagnoses obtained from the routine mortality statistics with the standardized World Health Organization (WHO) MONICA (multinational MONItoring of trends and determinants in CArdiovascular disease) classification in suspect coronary heart disease (CHD) deaths registered in the FINMONICA myocardial infarction (MI) register during 1983-1992. All CHD deaths from routine mortality statistics (International Classification of Diseases codes 410-414) were registered in the MI register. Of the CHD deaths in routine mortality statistics 1.7% in men and 4.8% in women did not fulfill the MONICA criteria for CHD death (P<0.001 for the difference between the sexes). In men 4.7% and in women 7.3% (P=0.004) of the deaths registered in the MI Register and classified as CHD deaths by MONICA criteria had another underlying cause of death than CHD in routine mortality statistics; this proportion increased over time in both sexes (P=0.002 in men and P=0.77 in women). The CHD mortality trends obtained separately from the routine mortality statistics and from the FINMONICA MI Register were very similar. In conclusion, the high CHD mortality in Finland reported by the routine mortality statistics is real. It is possible that some CHD deaths have escaped registration, but the decline seen in the CHD mortality is also real.

The validity of hospital discharge register data on coronary heart disease in Finland.

We studied the validity of the Finnish hospital discharge register data on coronary heart disease (CHD) for the purposes of epidemiologic studies and health services research. The Finnish nationwide hospital discharge register (HDR) was linked with the FINMONICA acute myocardial infarction (AMI) register for the years 1983-1990. The frequency of errors in the HDR was assessed separately. Between 8% and 13% of hospitalized AMI events registered in the AMI Register were not found in the HDR with an ICD code for CHD. Problems with the register linkage and the use of some ICD code other than one of the codes for CHD explained these missing events. The frequency of errors in the personal identification number was about 5% in the early 1980s. After 1986 errors were found only occasionally. The diagnosis recorded in the HDR was the same as that in the discharge sheet in about 95% of hospitalizations. The positive predictive value of the ICD code 410 (AMI), compared with the FINMONICA definite+possible AMI category, was very high and stable, about 90% in all areas and all hospitals, but the sensitivity varied from 50% at local hospitals to 80% at central hospitals. In summary, data on CHD obtained from the Finnish hospital discharge register give, on average, a correct picture on changes in the occurrence of AMI in Finland and can, with necessary caution, be used in epidemiological studies and health services research. However, the classification of individual cases is not standardized in the HDR, but varies over time, between geographical areas and the levels of care. Therefore, these data should not be used without confirmation in studies where correct classification of individual outcomes is of crucial importance, such as follow-up studies and case-control studies.

Decline of coronary heart disease mortality in Finland during 1983 to 1992: roles of incidence, recurrence, and case-fatality. The FINMONICA MI Register Study.

BACKGROUND: The rate of coronary heart disease (CHD) mortality in eastern Finland has been the highest in the world. The official mortality statistics suggest, however, that is has declined by 60% during the past 20 years. The aim of the present study was to examine the contributions of incidence, recurrence, and case fatality of coronary events to the trends in CHD mortality in three areas of Finland. METHODS AND RESULTS: Population-based myocardial infarction registers have been operating in the provinces of North Karelia and Kuopio in eastern Finland and the Turku/Loimaa area in southwestern Finland from 1983 to 1992. During this 10-year period, each suspected coronary event in persons 35 to 64 years of age was evaluated for registration. Of these, 13,566 fulfilled the criteria of myocardial infarction or coronary death. Almost one fourth (22.4%) of the coronary events were sudden, out-of-hospital deaths. Among men, the average change in mortality was -7.1% per year (95% confidence interval, -8.4% to -5.8%) in North Karelia, -5.0% per year (-7.0% to -3.0%) in Kuopio, and -4.9% per year (-8.2% to -1.6%) in Turku/Loimaa. Among women, the corresponding changes were -5.6% (-11.1% to -0.1%), -4.4% (-8.1% to -0.7%), and -8.1% (-13.0% to -3.2%). In eastern Finland, the decline in CHD mortality was due to a decline in recurrent coronary events but also in the incidence of first coronary events, whereas in southwestern Finland, the decline in case-fatality rate had the major role. CONCLUSIONS: The decline in CHD mortality rate in Finland appears to be the result of a successful combination of primary and secondary prevention measures and improvements in acute coronary care.

Diagnostic features of acute myocardial infarction--changes over time from 1983 to 1990: results from the FINMONICA AMI Register Study.

OBJECTIVES: To examine, whether the acute myocardial infarctions (AMIs) are becoming smaller. DESIGN: Analysis of electrocardiogram (ECG) and enzyme findings of community-based AMI registers in three geographical areas of Finland during the 8-year period 1983-90. SETTING: In the FINMONICA AMI Register, all suspected coronary events in persons aged 25-64 years have been registered since 1983 according to the protocol of the WHO MONICA project in the provinces of North Karelia and Kuopio in eastern Finland and Turku/Loimaa area in south-western Finland. SUBJECTS: Each consecutive case of suspected AMI originating from the monitored populations. During the study period, 11,487 definite or possible AMIs were registered. MAIN OUTCOME MEASURES: Trends in ECG findings classified as definite or probable, and trends in enzyme findings classified as abnormal or equivocal. RESULTS: Of the registered AMIs, 8439 (73.5%) reached the hospital alive and survived > or = 24 h from the beginning of the symptoms. They were included in the analyses of this report and divided further, to first ever AMIs (n = 5392) and to recurrent AMIs (3047). During the study period, the proportion of ECG findings classified as definite on the basis of the serial Minnesota coding declined in men 3.1% year-1 (P < 0.0001) on average for first AMIs and 1.9% year-1 (P = 0.004) for recurrent AMIs. In women, the corresponding declines were 1.9% year-1 (P = 0.007) and 1.6% year-1 (P = 0.02), respectively. Also, the proportion of enzymes classified as abnormal declined amongst men 2.2% year (P < 0.0001) for first AMIs and 2.8% year-1 (P < 0.0001) for recurrent AMIs. In women, the corresponding declines for abnormal enzymes was 1.3% year-1 (P = 0.13) and 3.0% year-1 (P = 0.02). These findings were consistent in all three areas with different registration teams and different laboratories. The proportion of definite ECG findings amongst patients hospitalized for AMI declined almost by half and the proportion of abnormal enzyme findings declined almost by one-third during the study period. CONCLUSIONS: Our findings are compatible with the clinical observation that the hospitalized AMIs are becoming smaller. The timing and magnitude of the changes suggest that they are mainly caused by decreased risk-factor levels in the population. Improved treatment of coronary heart disease and changed hospital admission policy are likely to be contributing factors.

Diagnosis of acute myocardial infarction by MONICA and FINMONICA diagnostic criteria in comparison with hospital discharge diagnosis.

WHO MONICA Project has suggested diagnostic criteria for acute myocardial infarction (AMI) for monitoring the trends of coronary heart disease (CHD). The aim of our study was to compare the diagnosis of AMI by the MONICA diagnostic criteria and by the modified criteria developed within the FINMONICA study with hospital discharge (clinical) diagnosis. In a series of 1565 suspected acute CHD events treated at Kuopio University Hospital in 1987-1990, a diagnosis of definite AMI was made clinically in 566 events and by the MONICA (and FINMONICA) criteria in 551 events. The comparability between clinical and MONICA (and FINMONICA) classifications was good (kappa 0.81, Ppos 0.88, Pneg 0.93). A diagnosis of definite or possible AMI was made clinically in 734 events, in 1249 events by the MONICA criteria (kappa 0.25, Ppos 0.69, Pneg 0.47) and in 934 events by the FINMONICA criteria (kappa 0.60, Ppos 0.81, Pneg 0.77). Of the 383 events classified as possible AMI by the FINMONICA criteria the clinical diagnosis was "prolonged angina pectoris attack" or "unstable angina" in 39%. The FINMONICA diagnostic criteria for AMI are closer to clinical diagnostic classification and offer a possibility for a more detailed classification of acute CHD events than the original MONICA criteria.

Coronary heart disease case fatality in four countries. A community study. The Acute Myocardial Infarction Register Teams of Auckland, Augsburg, Bremen, FINMONICA, Newcastle, and Perth.

BACKGROUND: Community-based registers participating in the MONICA Project of the World Health Organization show markedly different attack and death rates of coronary heart disease. This variation is a function of both the incidence and case fatality occurring within countries. The contribution of case fatality to the international variation in coronary heart disease mortality rates is not well understood. METHODS AND RESULTS: The register data from eight study populations--Augsburg and Bremen in Germany, Auckland in New Zealand, Perth and Newcastle in Australia, and North Karelia, Kuopio, and Turku/Loimaa in Finland--were compared. All patients with definite myocardial infarction or coronary death aged 35 to 64 years occurring in the study populations in 1985 through 1989 are the basis for the case fatality calculations by different definitions: 28-day case fatality for all cases, for hospitalized cases, and for hospitalized 24-hour survivors; out-of-hospital case fatality; and 24-hour case fatality for hospitalized cases. Differences in case fatality were much smaller than differences in attack and mortality rates in these populations. About two thirds of deaths occurred before the patients reached a hospital. The 28-day case fatality ranged from 37% for men in Perth to 58% for women in Augsburg. Among those who reached the hospital alive, 28-day case fatality was 13% to 27% for men and 20% to 35% for women. In those who survived 24 hours from the onset of symptoms, 28-day case fatality was 8% to 17% for men and 12% to 26% for women. CONCLUSIONS: Differences in case fatality were not associated with differences in coronary mortality rates between these populations. As most deaths occurred before reaching a hospital, opportunities for reducing case fatality through improved hospital care are limited. This emphasizes the primary role of prevention in reducing coronary death rates.

Trends in the incidence of and mortality from coronary heart disease in Finland, 1983-1988.

Trends in the incidence of and mortality from coronary heart disease during the period 1983-1988 were assessed in the population aged 35-64 years in three areas of Finland. The official mortality statistics and the FINMONICA (Finnish portion of the World Health Organization MONICA (Monitoring of Trends and Determinants in Cardiovascular Disease) project) Acute Myocardial Infarction Register were used as data sources. They both showed that coronary heart disease mortality declined steeply in Finnish men and women. This marked decline in coronary heart disease mortality was associated with a decline in the number of out-of-hospital coronary deaths. The changes in the incidence of acute myocardial infarction in men did not parallel the changes in mortality. No decline in incidence was seen in women in any of the study areas. These results suggest that the routine mortality statistics alone may give an overly favorable picture of coronary heart disease trends. Data on incidence are necessary to assess the need for the treatment and prevention of coronary heart disease.

Comparison of trends in ischaemic heart disease between North Karelia, Finland, and Kaunas, Lithuania, from 1971 to 1987.

OBJECTIVE: To compare the long-term trends in mortality and attack rate of ischaemic heart disease in North Karelia, Finland, and in Kaunas, Lithuania, from 1971 to 1987. DESIGN: Data on routine mortality statistics were obtained from the Central Statistical Office of Finland and from the Central City Archives of Kaunas. In addition, data from the community based myocardial infarction registers were used. The registers used similar diagnostic criteria and had operated in both areas during the entire study period. SETTING: The province of North Karelia in Finland and the city of Kaunas in Lithuania. SUBJECTS: The target populations were the people of North Karelia and Kaunas aged 35-64 years. MAIN OUTCOME MEASURES: Mortality from ischaemic heart disease and the attack rate of acute myocardial infarction. RESULTS: In North Karelia mortality from ischaemic heart disease and the attack rate of acute myocardial infarction declined steeply both in men and women. This decline was accompanied by a decrease in total mortality. In Kaunas, both mortality and the attack rate increased in men but remained unchanged in women. In 1985 to 1987, age standardised total mortality per 100,000 inhabitants was similar in the two populations in men (1081 (95% confidence interval (CI) 1013 to 1149), in North Karelia; 1082 (95% CI 1032 to 1132), in Kaunas). The proportional mortality from ischaemic heart disease was considerably higher in North Karelia (40%) than in Kaunas (28%). In women, age standardised total mortality was lower in North Karelia (350 (95% CI 312-388)) than in Kaunas (440 (95% CI 413 to 467)). The proportional mortality from ischaemic heart disease in women was also higher in North Karelia (28%) than in Kaunas (13%). CONCLUSIONS: Despite the remarkable decline in the occurrence of ischaemic heart disease, it still remains the most important cause of premature mortality in North Karelia. In Kaunas ischaemic heart disease mortality and attack rate increased in men. Experiences from successful cardiovascular disease prevention programmes in western countries, such as the North Karelia Project, should be exploited to prevent an increasing epidemic of ischaemic heart disease in eastern Europe.

Acute myocardial infarction (AMI) in Finland--baseline data from the FINMONICA AMI register in 1983-1985.

The acute myocardial infarction (AMI) register of the FINMONICA study, the Finnish part of the WHO-coordinated multinational MONICA project, operates in the provinces of North Karelia and Kuopio in eastern Finland and in Turku, Loimaa and in communities around Loimaa in southwestern Finland. The AMI register serves as an instrument for the assessment of trends in mortality from coronary heart disease (CHD) and of the incidence and attack rates of AMI among 25-64-year-old residents of the study areas. This report describes the methods used in the FINMONICA AMI register and the findings during the first 3 years of the study, in 1983-1985. The criteria of the multinational WHO MONICA project were used in the classification of fatal events and in the diagnosis of non-fatal definite AMI, but based on the experience within the FINMONICA study, stricter diagnostic criteria than those originally described in the WHO MONICA protocol were used for non-fatal possible AMI. This led to a marked improvement in the comparability of the data from the three study areas with regard to the incidence and attack rates of non-fatal AMI. During the 3-year period the total number of registered events was 6266 among men and 2092 among women. Among men the incidence and attack rates of AMI and mortality from CHD were higher in eastern than in southwestern Finland. Also among women the incidence and attack rates of AMI were higher in eastern than in southwestern Finland, whereas there was no regional difference in mortality from CHD among women. The mortality findings of the FINMONICA AMI Register were in good agreement with the official CHD mortality statistics of Finland.

Trends and determinants of ischaemic heart disease mortality in Finland: with special reference to a possible levelling off in the early 1980s.

There has been a general decline in mortality from ischaemic heart disease (IHD) in Finland since the beginning of the 1970s. An intensified preventive programme was started in the province of North Karelia in 1972. Between 1974 and 1979 the decline in IHD mortality in North Karelian men was steeper than that in the rest of Finland. This favourable trend was associated with a fall in the levels of major coronary disease risk factors. Case-fatality from acute coronary events did not change much during this period. A levelling off in the decline in IHD mortality has been observed in the 1980s first in North Karelia and later in the whole of Finland. These findings from the official mortality statistics were confirmed in North Karelia by the data from the population-based coronary register. This levelling off in the decline in IHD mortality was associated with levelling off in risk-factor reductions in eastern Finland and with little improvement in risk-related behaviours in Finland during the 1980s. The IHD rates are still high and associated with persistent high risk factor levels and particularly with high serum cholesterol and blood pressure levels. Together with IHD mortality, the decline in total mortality also levelled off both in North Karelia and in the rest of Finland during the early 1980s. Compared with other countries, the rates of coronary disease and total mortality in the middle-aged Finnish population, especially among men, are among the highest in the world.(ABSTRACT TRUNCATED AT 250 WORDS)

Contribution of electrocardiograms, serum enzymes and history of chest pain to the diagnosis of acute myocardial infarction--a community-based register study in North Karelia, Finland, 1972-1981.

The contribution of electrocardiograms, serum enzymes and history of chest pain to the diagnosis of acute myocardial infarction (AMI) was examined in a series of 3123 persons with a definite acute myocardial infarction registered in a community-based myocardial infarction register study in North Karelia, eastern Finland in 1972-1981. Criteria for chest pain history, serum enzyme and electrocardiographic findings were those used in the WHO co-ordinated myocardial infarction register studies. The history of chest pain typical of AMI was obtained in approximately 90% of both men and women in all age groups. Among persons with first AMI, the proportion of unequivocal ECG changes was higher among men than in women and declined with age in both sexes (81.8% in men 20-44 years of age, 47.8% in men 75 years of age or more; 61.7% in women 20-54 years of age and 45-6% in women 75 years of age or more) and lower among persons with recurrent AMI, but even among them it decreased with age. The proportion of serum enzyme elevations was approximately 90% in all subgroups. The results of the present study reconfirm that the contribution of elevated serum enzymes is particularly important in patients with recurrent acute myocardial infarction and old age. Elevated serum enzymes should receive greater attention in surveillance studies aiming to detect trends in AMI incidence in populations.

Changes in morbidity and mortality during comprehensive community programme to control cardiovascular diseases during 1972-7 in North Karelia.

A comprehensive community programme studying the control of cardiovascular diseases (CVD) was carried out in North Karelia, Finland, between 1972 and 1977. The main objective was to reduce the mortality and morbidity of CVD, particularly in middle-aged men. Changes in the mortality and incidence of CVD were monitored by community-based registers of cases of acute myocardial infarction (AMI) and stroke and data on death certificates. During the programme the total mortality in the area decreased by 5% and the mortality from CVD decreased by 13% among men and 31% among women aged 30-64 years. The incidence of AMI fell by 16% among men and 5% among women, while that of cerebral stroke fell by 38% among men and 50% among women. Changes in mortality in North Karelia were compared with those in a matched control area; the difference between the two areas was not significant. The true effect of the programme cannot be deduced from these results, but mortality from CVD and the incidence of AMI and stroke fell during the five years studied. Thus the changes in mortality and morbidity of CVD accorded with the initial objectives of the programme.

PIP: Over the 1972-1977 period a comprehensive community program studying the control of cardiovascular diseases (CVD) was conducted in North Karelia, Finland. The program intention was to reduce the mortality and morbidity of CVD, particularly among middle-aged men. Community-based registers of cases of acute myocardial infarction (AMI) and stroke and data on death certificates were used to monitor changes in the mortality and incidence of CVD. During the course of the program the total mortality in the area decreased by 5%, and the mortality from CVD decreased by 13% among men and 31% among women aged 30-64 years. The incidence of AMI declined by 16% among men and 5% among women, while that of cerebral stroke declined by 38% among men and 50% among women. Changes in mortality in North Karelia were compared with those in a matched control area. There was no significant difference between the 2 areas. Although the true effect of the program cannot be deduced from these results, mortality from CVD and the incidence of AMI and stroke did decline during the 5-year study period, which was in accordance with the initial program objectives.

Incidence and presentation of myocardial infarction in North Karelia, Finland.

A myocardial infarction (mi) register was started on May 1, 1972 in the county of North Karelia in Eastern Finland as a part of the North Karelia project. Information about all cases with a suspected acute MI among the North Karelian population are collected by the register. The principles of the register follow the recommendations of the WHO expert working group. Altogether 713 cases were registered between May 1, and Dec. 31,1972. The distribution of them into diagnostic categories was: "definite" 57%, "possible" 30%, "no acute MI" 8% and "insufficient information" 5%. Patients with no acute MI have been excluded in the results. About 47% of the male patients below 65 years had a history of previous MI. Most of the patients in the group had been heavy cigarette smokers, eating mainly butter as the fat in their diet. Overweight was rare among the male patients but not among the females. During the years preceding the attack, most of the patients had visited a physician and a pathological ECG had been recorded. The average time delay before hospital treatment was internationally relatively short. The 4 week fatality rate among patients below 65 years was 37% for males and 35% for females. These rates were slightly lower than those in the register material in Helsinki. The annual incidence rate per thousand for the age group 30-64 in North Karelia was 13.8 among males and 2.6 among females. The incidence rate increased continuously with age among males,among females it increased markedly only after the age of 60. The risk ratio between North Karelia and Helsinki for the age standardized incidence rates of males in the age group 30-64 was 1.38, and for respective mortality rates 1.21. Within North Karelia the highest incidence rate for males aged 30-64 was recorded in the rural area of Ilomantsi-Tuupovaara in the East.