Risk factors for major adverse cardiovascular events after the first acute coronary syndrome

AIMS

To evaluate risk factors for major adverse cardiac event (MACE) after the first acute coronary syndrome (ACS) and to examine the prevalence of risk factors in post-ACS patients.

METHODS

We used Finnish population-based myocardial infarction register, FINAMI, data from years 1993-2011 to identify survivors of first ACS (n = 12686), who were then followed up for recurrent events and all-cause mortality for three years. Finnish FINRISK risk factor surveys were used to determine the prevalence of risk factors (smoking, hyperlipidaemia, diabetes and blood pressure) in post-ACS patients (n = 199).

RESULTS

Of the first ACS survivors, 48.4% had MACE within three years of their primary event, 17.0% were fatal. Diabetes (p = 4.4 × 10-7), heart failure (HF) during the first ACS attack hospitalization (p = 6.8 × 10-15), higher Charlson index (p = 1.56 × 10-19) and older age (p = .026) were associated with elevated risk for MACE in the three-year follow-up, and revascularization (p = .0036) was associated with reduced risk. Risk factor analyses showed that 23% of ACS survivors continued smoking and cholesterol levels were still high (>5mmol/l) in 24% although 86% of the patients were taking lipid lowering medication.

CONCLUSION

Diabetes, higher Charlson index and HF are the most important risk factors of MACE after the first ACS. Cardiovascular risk factor levels were still high among survivors of first ACS.

The validity of hospital discharge register data on non-ST-elevation and ST-elevation myocardial infarction in Finland

Objectives. To examine the validity of ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) diagnoses in Finnish nation-wide hospital discharge register (HDR). Design. In the first stage of the study, we sampled 180 patients treated in 1996-2012 for MI in three different hospitals, Oulu university hospital, Turku university hospital and North Karelia Central hospital, 60 patients in each hospital. A cardiology resident classified the patients on the basis of ECG finding into following categories: NSTEMI, STEMI or not classifiable myocardial infarction (NCMI). In the second stage of the study, we sampled altogether 270 additional patients i.e. 90 patients per hospital. Patients were treated between 2012-2014 for STEMI (n = 3 × 30), NSTEMI (n = 3 × 30), and NCMI (n = 3 × 30). The ECGs of these patients were independently evaluated by the cardiology resident and a senior cardiologist and compared with the HDR diagnosis. Results. In the first stage of the study, the agreement between the ECG coding of the cardiology resident and the HDR diagnoses was poor (Cohen's kappa coefficient 0.38 (95% CI 0.10-0.32). In the second stage, the agreement remained at the same poor level (Cohen's kappa = 0.22 (95% CI 0.11-0.03)). The agreement between the cardiology resident and the senior cardiologist was, however, good (Cohen's kappa = 0.75 (95% CI 0.65-0.85)). Conclusions. Our results show that the division of MI diagnoses to STEMI and NSTEMI is not reliable in the Finnish HDR. These diagnoses should not be used as outcomes in scientific research without additional verification from the original ECGs.

Outcomes of Secondary Prevention among Coronary Heart Disease Patients in a High-Risk Region in Finland

Despite comprehensive national treatment guidelines, goals for secondary prevention of coronary heart disease (CHD) have not been sufficiently met everywhere in Finland. We investigated the recorded risk factor rates of CHD and their spatial differences in North Karelia Hospital District, which has a very high cardiovascular burden, in order to form a general view of the state of secondary prevention in a high-risk region. Appropriate disease codes of CHD-diagnoses and coding for percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) were used to identify from the electronic patient records the patient group eligible for secondary prevention. The cumulative incidence rate of new patients (n = 2556) during 2011–2014 varied from 1.9% to 3.5% between municipalities. The success in secondary prevention of CHD was assessed using achievement of treatment targets as defined in national guidelines. Health centres are administrated by municipalities whereupon the main reporting units were municipalities, together with composed classification of patients by age, gender and dwelling location. Health disparities between municipalities, settlement types and patient groups were found and are interpreted. Moreover, spatial high-risk and low-risk clusters of acute CHD were detected. The proportion of patients achieving the treatment targets of low-density lipoprotein cholesterol (LDL-C) varied from 21% to 38% between municipalities. Variation was also observed in the follow-up of patients; e.g., the rate of follow-up measurements of LDL-C in municipalities varied from 72% to 86%. Spatial variation in patients’ sociodemographic and neighbourhood characteristics and morbidity burden partly explain the differences in outcomes, but there are also very likely differences in the care process between municipalities which requires a study in its own right.

Case fatality of acute coronary events is improving even among elderly patients; the FINAMI study 1995-2012

AIM

To examine trends in incidence and 28-day case fatality of myocardial infarction (MI) in persons aged 75-99 years in four areas of Finland.

METHODS AND RESULTS

The Finnish Acute Myocardial Infarction (FINAMI) register is a population-based MI register study, which during 1995-2012 recorded 30561 suspected acute coronary syndromes in persons aged ≥75 years. Of them, 16229 fulfilled the American Heart Association criteria for a definite, probable or possible MI or coronary death. This age-group contributed 56.8% of all MIs of which 62.7% occurred in women. The incidence of MI decreased by -3.3%/year (95% CI -4.2; -2.4) in women aged 75-84 years, and by -1.2%/year (-1.9; -0.5) in women aged 85-99 years, but among men in these age-groups, only a non-significant reduction occurred. The 28-day case fatality of MI was high. In the age-group 75-84 years, it decreased non-significantly by -1.6%/year in men, and significantly by -2.4%/year (-3.9; -0.8) in women. In the age-group 85-99 years, the decrease was more remarkable: -5.1%/year (-7.8; -2.3) and -3.9%/year (-5.5; -2.2), respectively.

CONCLUSIONS

In Finland, more than half of MIs occur in the age-group 75-99 years, and most of them in women. The incidence of MI decreased significantly in elderly women but non-significantly in elderly men. The 28-day case fatality decreased especially in the age-group 85-99 years. Key Messages In Finland, more than one half of all myocardial infarctions (MIs) occur in the age-group of 75 years or older. Furthermore, 62.7% of MIs among elderly patients occur among women, although 58.0% of the elderly population are women. The incidence of MI decreased significantly in elderly women but not in elderly men. The 28-day case fatality in elderly patients was high but decreased significantly during the study period 1995-2012. This study provides population-based data on treatment strategies and trends in incidence, event rate, mortality and case fatality of MI in elderly individuals. Elderly patients with acute coronary syndromes still present a remarkable burden to the healthcare system in Finland as well as in many other developed countries. Especially considering the modern trend of reducing hospital resources and shifting patient care to outpatient clinics, the epidemiology of MI in elderly patients remains an important issue for the future planning of the healthcare system.

Decreased mortality risk due to first acute coronary syndrome in women with postmenopausal hormone therapy use

OBJECTIVES

The role of postmenopausal hormone therapy (HT) in the incidence of acute coronary syndrome (ACS) has been studied extensively, but less is known of the impact of HT on the mortality risk due to an ACS.

STUDY DESIGN AND MAIN OUTCOME MEASURES

We extracted from a population-based ACS register, FINAMI, 7258 postmenopausal women with the first ACS. These data were combined with HT use data from the National Drug Reimbursement Register; 625 patients (9%) had used various HT regimens. The death risks due to ACS before admission to hospital, 2-28, or 29-365days after the incident ACS were compared between HT users and non-users with logistic regression analyses.

RESULTS

In all follow-up time points, the ACS death risks in HT ever-users were smaller compared to non-users. Of women with HT ever use, 42% died within one year as compared with 52% of non-users (OR 0.62, p<0.001). Most deaths (84%) occurred within 28days after the ACS, and in this group 36% of women with ever use of HT (OR 0.73, p=0.002) and 30% of women with ≥5year HT use (OR 0.54, p<0.001) died as compared to 43% of the non-users. Age ≤60 or >60 years at the HT initiation was accompanied with similar reductions in ACS mortality risk.

CONCLUSIONS

Postmenopausal HT use is accompanied with reduced mortality risk after primary ACS.

Sex differences in short- and long-term case-fatality of myocardial infarction

Declining trends in case fatality (CF) of MI events have been generally reported in western countries. It is, however, not clear whether the development has been equally beneficial in both sexes. Data from two large population based registers, FINAMI and the Finnish National Cardiovascular Disease Register (CVDR) were used to determine whether the CF of incident MI events has declined less in women than in men. All patients aged 35 and over were included. CF was calculated for different time periods after the onset of the MI event, the main emphasis was in pre-hospital, 28-day, and 1-year CF. Figures were compared between two study periods: 1994-1996 and 2000-2002. A total of 6,342 incident MI events were recorded in FINAMI and 117,632 events in CVDR during the study periods. Comparison between the two study periods showed that the CF was generally declining. However, a slower decline in short-term CF was seen among young (aged<55 years) women (P for sex by study period interaction in pre-hospital CF=0.028 in FINAMI and 0.003 in CVDR, and for 28-day CF P=0.016 in FINAMI and <0.0001 in CVDR). In conclusion, the short and long-term prognosis of MI events has improved in both sexes. Pre-hospital CF has declined less among younger women than among men and among older women. This slower decline in early CF was responsible for the slower improvement in 28-day and 1-year prognosis in young women.

Coronary events in persons aged 75 years or older in Finland from 1995 to 2002: the FINAMI study

The authors used population-based myocardial infarction (MI) register data to examine trends in incidence, case fatality, treatment strategies of MI, and coronary heart disease (CHD) mortality in persons aged 75 to 99 years in 4 areas of Finland during 1995 through 2002. This age group contributed 53% (n=13,977) of all CHD events, and 65% occurred in women. CHD mortality declined among men annually by 3.5% and 1.0% in the 75- to 84-year-old and 85- to 99-year-old age groups, respectively. Among women, it declined by 2.2% per year in the 75- to 84-year-old age group but increased by 1.3% per year in the 85- to 99-year-old age group. MI attack rate did not change in men but increased significantly in women aged 85 to 99 years. Clinical management of MI in elderly patients was more conservative than in middle-aged patients. In conclusion, one-half of all CHD events occur among persons aged 75 years or older, and elderly patients with CHD represent an increasing burden to the health care system.

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.

Are coronary event rates declining slower in women than in men - evidence from two population-based myocardial infarction registers in Finland?

Background

Studies have suggested that the prevention and treatment of coronary heart disease may not have been as effective in women as in men. Therefore, we aimed to examine whether the incidence, attack rate and mortality of myocardial infarction (MI) events have declined less in women than in men.

Methods

Two large population-based MI registers, the FINAMI register and the Finnish Cardiovascular Disease Register (CVDR) were used for comparing the event rates among men and women aged ≥35 years in two time periods, 1994–1996 and 2000–2002.

Results

In the FINAMI register a total of 5,252 events were recorded in men and 4,898 in women. Corresponding numbers in the CVDR were 78,709 and 70,464. Both FINAMI and CVDR data suggested smaller declines in incidence and attack rate of MI events in women than in men. In CVDR data the decline in mortality was also smaller in women than in men, while in FINAMI data this difference did not reach statistical significance. In the large CVDR data set, negative binomial regression models revealed smaller declines in incidence (p = 0.006), attack rate (p = 0.008) and mortality (p = 0.04) in women than in men aged <55 years. In persons ≥55 years no difference was observed between women and men.

Conclusion

The incidence and attack rate of MI events have declined less in women aged <55 than in men of similar age. In older persons no significant differences were observed. Further studies are warranted to find out the reasons why the development has been less favourable for young women than for men.

The effect of correcting for troponins on trends in coronary heart disease events in Finland during 1993-2002: the FINAMI study

AIMS

The object of this study is to analyse the trends in coronary events in Finland during 1993-2002, correcting for the effect of troponins.

METHODS AND RESULTS

A population-based myocardial infarction register recorded all coronary events (n=14 782) in four geographical areas of Finland during 1993-2002. Correction coefficients for the effect of troponins were calculated on the basis of 4359 coronary events, with simultaneous determination of troponins and the 'old' enzymatic markers of myocardial injury. Coronary mortality declined steeply, except in women aged > or = 75 years. The incidence of first coronary events declined 2.0% (95% confidence interval -3.0, -0.9%) per year among men and 1.0% (-2.7, 0.6%) per year among women aged 35-74 years. After correcting for the effect of troponins, also the decline among women became statistically significant: 2.7% (-4.5, -0.8%) per year. The effect of troponins tended to be stronger in women and older individuals than in men and younger individuals. The 28-day case fatality declined among men, but not among women. The effect of troponins on case fatality trends was weak.

CONCLUSION

Declining trends in the incidence of coronary events in Finland during 1993-2002 were partly hidden by the effect of troponins. Both incidence and case fatality declines have contributed to the decline in mortality.

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.

Explaining the decline in coronary heart disease mortality in Finland between 1982 and 1997

In Finland since the 1980s, coronary heart disease mortality has declined more than might be predicted by risk factor reductions alone. The aim of this study was to assess how much of the decline could be attributed to improved treatments and risk factor reductions. The authors used the cell-based IMPACT mortality model to synthesize effectiveness of treatments and risk factor reductions with data on treatments administered to patients and trends in cardiovascular risk factors in the population. Cardiovascular risk factors were measured in random samples of patients in 1982 (n=8,501) and 1997 (n=4,500). Mortality and treatment data were obtained from the National Causes of Death Register, Hospital Discharge Register, social insurance data, and medical records. Estimated and observed changes in coronary heart disease mortality were used as main outcome measures. Between 1982 and 1997, coronary heart disease mortality rates declined by 63%, with 373 fewer deaths in 1997 than expected from baseline mortality rates in 1982. Improved treatments explained approximately 23% of the mortality reduction, and risk factors explained some 53-72% of the reduction. These findings highlight the value of a comprehensive strategy that promotes primary prevention programs and actively supports secondary prevention. It also emphasizes the importance of maximizing population coverage of effective treatments.

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.

The validity of the Finnish Hospital Discharge Register and Causes of Death Register data on coronary heart disease

BACKGROUND AND DESIGN

The recent introduction of sensitive markers of myocardial injury is likely to affect the epidemiology of coronary heart disease (CHD). The American Heart Association together with other societies and research agencies have recently published a new definition on acute CHD to improve consistency in epidemiological and clinical studies (referred here as the '2003 definition').

METHODS

In this study we compare the data on CHD events in the Finnish National Hospital Discharge Register (HDR) and the Causes of Death Register (CDR) with the population-based myocardial infarction (MI) register, FINMONICA/FINAMI. The FINMONICA/FINAMI events were classified according to the 2003 definition. The relevant International Classification of Diseases (ICD) codes from the HDR and CDR were used.

RESULTS

Using the 2003 definition as the reference, the overall sensitivity of the ICD codes for MI in the combined HDR and CDR was 83% and the positive predictive value (PPV) was 90%. When the ICD codes for unstable angina were added to the analyses, the sensitivity improved to 85% and the PPV declined to 83%. In the age group 35-74 the sensitivity of the MI codes improved over time, in men from 64% in 1988-1992 to 81% in 1998-2002, and in women from 61 to 78%, respectively. The oldest age group, 75 years or older, had sensitivity and PPV values comparable to those of the younger.

CONCLUSION

Diagnoses of fatal and non-fatal CHD events in the Finnish HDR and Causes of Death register were reasonably valid indicators for hard CHD events when compared with the FINMONICA/FINAMI register data.

A new definition for myocardial infarction: what difference does it make?

AIMS

As a response to changing diagnostic tools of myocardial infarction (MI), new case definitions for acute coronary events were published in 2003 as the American Heart Association Scientific Statement. We assessed the new definition in hospitalized patients in a large population-based MI register study.

METHODS AND RESULTS

We identified all suspected acute coronary syndromes with data either on troponin T or on troponin I and at least one of the enzymatic markers of myocardial injury (n=6104). The 2003 definition with the use of troponins identified 83% more definite MIs than the WHO MONICA definition using cardiac enzymes. The additional patients were older, had more often diabetes, and received less often thrombolysis and revascularization than those having MI by both definitions. Adjusting for age, sex, study area, and study year, the additional patients with their first MI aged 25-74 had a higher risk of cardiovascular death within 1 year than patients having definite MI by both definitions (hazard ratio 1.6, 95% CI 1.1-2.2).

CONCLUSION

The changing diagnostic criteria present a considerable challenge for the assessment of long-term trends in MI events in the community as well as for longitudinal studies of the natural history of MI. The 2003 definition, when applied using troponins, identified a sizable new group of MI patients, among persons with suspected acute coronary syndrome, at high risk of a recurrent event.

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.

Geographical variation in the incidence of acute myocardial infarction in eastern Finland--a Bayesian perspective

BACKGROUND

Large geographical variation in the incidence and mortality of cardiovascular disease (CHD) has been repeatedly reported in Finland with persistent difference between east and west. We undertook this study to estimate the geographical distribution of Acute Myocardial Infarction (AMI) incidence in the high-risk province of North Karelia and in the province of Kuopio.

METHODS

Data on men aged 25-64 years with first event of acute myocardial infarction (AMI) were obtained from the FINMONICA AMI register, which recorded detailed information of AMI events during the period 1983 to 1992. The geographical pattern of AMI incidence was studied in two five-year periods 1983 to 1987 and 1988 to 1992 separately in 10 km x 10 km grid cells employing the Geographical Information System (GIS) and a Bayesian hierarchical approach.

RESULTS

In both periods Bayesian modeling revealed a geographical pattern of AMI incidence and high risk (probability that incidence exceeds the observed mean incidence) in the remote rural areas.

CONCLUSIONS

Detection of high-risk areas in both provinces showed that underlying environmental and/or genetic risk factors of AMI are not evenly distributed within the province but enriched in certain geographical non-administratively defined locations in eastern Finland.

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.

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.

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.