Long-term prognosis after coronary artery bypass surgery.

OBJECTIVE: To analyse the risk of coronary heart disease (CHD) events and total mortality among patients who had coronary artery bypass graft (CABG) surgery during 1988-1992. METHODS: A population-based myocardial infarction (MI) register included data on invasive cardiac procedures among residents of the study area. The subjects aged 35-64 years were followed-up for 12 years for non-fatal and fatal CHD events and all-cause mortality, excluding events within 30 days of the CABG operation. CABG was performed on 1158 men and 215 women. RESULTS: The overall survival of men who underwent CABG was similar to the survival of the corresponding background population for about ten years but started to worsen after that. At twelve years of follow-up, 23% (n=266, 95% CI 234-298) of the men who had undergone the operation had died, while the expected proportion, based on mortality in the background population, was 20% (n=231, 95% CI 226-237). The CHD mortality of men who had undergone the operation was clearly higher than in the background population. Among women, the mortality after CABG was about twice the expected mortality in the corresponding background population. In Cox proportional hazards models age, smoking, history of MI, body mass index and diabetes were significant predictors of mortality. CONCLUSIONS: The prognosis of male CABG patients did not differ from the prognosis of the corresponding background population for about ten years, but started to deteriorate after that. History of MI prior to CABG and major cardiovascular risk factors was a predictor of an adverse outcome.

Myocardial infarction in diabetic and non-diabetic persons with and without prior myocardial infarction: the FINAMI Study.

AIMS/HYPOTHESIS: We compared the risk of acute coronary events in diabetic and non-diabetic persons with and without prior myocardial infarction (MI), stratified by age and sex. METHODS: A Finnish MI-register study known as FINAMI recorded incident MIs and coronary deaths (n=6988) among people aged 45 to 74 years in four areas of Finland between 1993 and 2002. The population-based FINRISK surveys were used to estimate the numbers of persons with prior diabetes and prior MI in the population. RESULTS: Persons with diabetes but no prior MI and persons with prior MI but no diabetes had a markedly greater risk of a coronary event than persons without diabetes and without prior MI. The rate of recurrent MI among non-diabetic men with prior MI was higher than the incidence of first MI among diabetic men aged 45 to 54 years. The rate ratio was 2.14 (95% CI 1.40-3.27) among men aged 50. Among elderly men, diabetes conferred a higher risk than prior MI. Diabetic women had a similar risk of suffering a first MI as non-diabetic women with a prior MI had for suffering a recurrent MI. CONCLUSIONS/INTERPRETATION: Both persons with diabetes but no prior MI, and persons with a prior MI but no diabetes are high-risk individuals. Among men, a prior MI conferred a higher risk of a coronary event than diabetes in the 45-54 year age group, but the situation was reversed in the elderly. Among diabetic women, the risk of suffering a first MI was similar to the risk that non-diabetic women with prior MI had of suffering a recurrent MI.

Five-year risk of developing clinical diabetes after first myocardial infarction; the FINAMI study.

AIM: To investigate the incidence of clinical diabetes as determined by the incidence of diabetes drug reimbursements within a 5-year period after the first myocardial infarction (MI) in patients who were non-diabetic at the time of their first MI. RESEARCH DESIGN AND METHODS: A population-based MI register, FINMONICA/FINAMI, recorded all coronary events in persons of 35-64 years of age between 1988 and 2002 in four study areas in Finland. These records were used to identify subjects sustaining their first MI (n = 2632). Participants of the population-based risk factor survey FINRISK (surveys 1987, 1992, 1997 and 2002), who did not have diabetes or a history of MI, served as the control group (n = 7774). The FINMONICA/FINAMI study records were linked with the National Social Security Institute's drug reimbursement records, which include diabetes medications, using personal identification codes. The records were used to identify subjects who developed diabetes during the 5-year follow-up period (n = 98 in the MI group and n = 79 in the control group). RESULTS: Sixteen per cent of men and 20% of women sustaining their first MI were known to have diabetes and thus were excluded from this analysis. Non-diabetic men having a first MI were at more than twofold {hazard ratio (HR) 2.3 [95% confidence interval (CI) 1.6-3.4]}, and women fourfold [HR 4.3 (95% CI 2.4-7.5)], risk of developing diabetes mellitus during the next 5 years compared with the control population without MI. CONCLUSIONS: Many patients who do not have diabetes at the time of their first MI develop diabetes in the following 5 years.

Decline in out-of-hospital coronary heart disease deaths has contributed the main part to the overall decline in coronary heart disease mortality rates among persons 35 to 64 years of age in Finland: the FINAMI study.

BACKGROUND: Out-of-hospital deaths constitute the majority of all coronary heart disease (CHD) deaths and are therefore of considerable public health significance. METHODS AND RESULTS: We used population-based myocardial infarction register data to examine trends in out-of-hospital CHD deaths in Finland during 1983 to 1997. We included in out-of-hospital deaths also deaths in the emergency room and all deaths within 1 hour after the onset of symptoms. Altogether, 3494 such events were included in the analyses. The proportion of out-of-hospital deaths of all CHD deaths depended on age and gender. In the age group 35 to 64 years, it was 73% among men and 60% among women. These proportions did not change during the study. The annual average decline in the age-standardized out-of-hospital CHD death rate was 6.1% (95% CI, -7.3, -5.0%) among men and 7.0% (-10.0, -4.0%) among women. These declines contributed among men 70% and among women 58% to the overall decline in CHD mortality rate. In all, 58% of the male and 52% of the female victims of out-of-hospital CHD death had a history of symptomatic CHD. Among men with a prior history of myocardial infarction, the annual average decline in out-of-hospital CHD deaths was 5.3% (-7.2, -3.2%), and among men without such history the decline was 2.9% (-4.4, -1.5%). Among women, the corresponding changes were -7.8% (-14.2, -1.5%) and -4.5% (-8.0, -1.0%). CONCLUSIONS: The decline in out-of-hospital CHD deaths has contributed the main part to the overall decline in CHD mortality rates among persons 35 to 64 years of age in Finland.

Trends in coronary events in Finland during 1983-1997. The FINAMI study.

AIMS: To analyse the trends in incidence, recurrence, case fatality, and treatments of acute coronary events in Finland during the 15-year period 1983-97. METHODS AND RESULTS: Population-based MI registration has been carried out in defined geographical areas, first as a part of the FINMONICA Project and then continued as the FINAMI register. During the study period, 6501 coronary heart disease (CHD) events were recorded among men and 1778 among women aged 35-64 years. The CHD mortality declined on average 6.4%/year (95% confidence interval -5.4, -7.4%) among men and 7.0%/year (-4.7, -9.3%) among women. The mortality from recurrent events declined even more steeply, 9.9%/year (-8.3, -11.4%) among men and 9.3%/year (-5.1, -13.4%) among women. The proportion of recurrent events of all CHD events also declined significantly in both sexes. Of all coronary deaths, 74% among men and 61% among women took place out-of-hospital. The decline in 28-day case fatality was 1.3%/year (-0.3, -2.3%) among men and 3.1%/year (-0.7, -5.5%) among women. CONCLUSIONS: The study period was characterized by a marked reduction in the occurrence of recurrent CHD events and a relatively modest reduction in the 28-day case fatality. The findings suggest that primary and secondary prevention have played the main roles in the decline in CHD mortality in Finland.

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.

Trends in the treatment of patients with myocardial infarction and coronary revascularization procedures in Finland during 1986-92: the FINMONICA Myocardial Infarction Register Study.

OBJECTIVES: To investigate changes in the medical treatment of patients with myocardial infarction and the trends in revascularization procedures in Finland. DESIGN: A population-based myocardial infarction (MI) register study. SETTING: Populations, aged 25-64 years, of the three geographical areas of Finland, provinces of North Karelia and Kuopio in eastern Finland and the Turku-Loimaa area in south-western Finland. MAIN OUTCOME MEASURES: Medical treatment administered prior to the coronary event, during the hospitalization and at discharge from hospital to all patients hospitalized due to suspected myocardial infarction and all CAD deaths occurring during three separate 4-month periods in 1986, 1989 and 1992. Data on coronary bypass surgery and percutaneous coronary angioplasty in the study areas for 1986-92. RESULTS: The most marked change in the medical treatment of hospitalized myocardial infarction patients was the significant increase in the use of thrombolytic treatment (5% of patients in 1986 and 24% in 1992, P < 0.001 for trend). The use of antiplatelet agents increased from 1986 to 1992 prior to the coronary event, during the hospitalization and at discharge. The use of beta-blockers and intravenous nitrates increased and the use of calcium-channel blockers declined significantly in hospitalized patients during the study period. Hospitalized male myocardial infarction patients were treated more often with beta-blockers, nitrates, antiplatelet agents and thrombolytic agents than female patients, suggesting less intensive medical treatment in women. CONCLUSION: The results of the large clinical trials regarding the medical treatment of myocardial infarction patients were adopted in the clinical practice rapidly and the treatment of myocardial infarction patients and the number of revascularization procedures changed markedly from 1986 to 1992 in Finland. These changes may in part explain the favourable changes in mortality from CAD in Finland.

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.

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.

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.