Job strain predicts recurrent events after a first acute myocardial infarction: the Stockholm Heart Epidemiology Program

Abstract. László KD, Ahnve S, Hallqvist J, Ahlbom A, Janszky I. (Karolinska Institute, Stockholm, Sweden; Semmelweis University, Budapest, Hungary; Uppsala University, Uppsala, Sweden; and Karolinska Institute, Stockholm, Sweden). Job strain predicts recurrent events after a first acute myocardial infarction: the Stockholm Heart Epidemiology Program. J Intern Med 2010; 267 :599–611. Objectives. Studies investigating the prognostic role of job stress in coronary heart disease are sparse and have inconclusive findings. We aimed (i) to investigate whether job strain predicts recurrent events after acute myocardial infarction (AMI) and if so (ii) to determine behavioural and biological factors that contribute to the explanation of this association. Design. Prospective study. Setting. Ten emergency hospitals in the larger Stockholm area, Sweden. Subjects. Non‐fatal AMI cases from the Stockholm Heart Epidemiology Program case–control study who were employed and younger than 65 years at the time of their hospitalization (n = 676). Results. During the 8.5 year follow‐up, 155 patients experienced cardiac death or non‐fatal AMI; totally 96 patients died, 52 of cardiac causes. After adjustment for potential confounders, patients with high job strain had an increased risk for the combination of cardiac death and non‐fatal AMI relative to those with low job strain, the hazard ratio (HR) and the 95% confidence interval (CI) being 1.73 (1.06–2.83). Results were similar for cardiac [HR (95% CI): 2.81 (1.16–6.82)] and total mortality [HR (95% CI): 1.65 (0.91–2.98)]. We found no evidence for mediation from lifestyle, sleep, lipids, glucose, inflammatory and coagulation markers on the association between job strain and the combination of cardiac death and non‐fatal AMI. Conclusions. Job strain was associated with poor long‐term prognosis after a first myocardial infarction. Interventions focusing on reducing stressors at the workplace or on improving coping with work stress in cardiac patients might improve their survival post‐AMI.     

Association of interleukin 8 with myocardial infarction: Results from the Stockholm Heart Epidemiology Program

Background

Interleukin 8 (IL8) has been contradictorily associated with the risk of myocardial infarction (MI).

Aim

To investigate the association of IL8 serum levels with the risk of MI and the association of the IL8 (IL8) and IL8 receptors (CXCR1 and CXCR2) genetic variants with IL8 levels and MI risk in a large case control study, the Stockholm Heart Epidemiology Program.

Methods and results

IL8 levels (pg/mL) were divided into quartiles and the MI risk was calculated by logistic regression and expressed as odds ratio (OR) and 95% CI. Two IL8 SNPs (rs4073A/T, rs2227306C/T) and three SNPs tagging CXCR1 and CXCR2 (rs4674258C/T, rs1008563C/T, rs6723449T/C) were analyzed for association with IL8 levels and with MI risk.Multivariate adjusted ORs for MI risk by IL8 levels in the highest quartiles indicated reduced point estimates in both women (OR 0.37; 95% CI 0.2–0.8) and men when compared to the lowest quartile. In female cases, IL8 levels decreased progressively in the six months after MI (p = 0.03). IL8, CXCR1 and CXCR2 genetic variants were not associated with IL8 levels. In men, the T allele at the IL8 SNP rs4073 was associated with a slight increase in the MI risk under an additive and a recessive model of inheritance.

Conclusions

IL8 serum levels were associated with a reduced occurrence of MI among women, whereas IL8 was associated with a slightly increased risk among men, possibly through different mechanisms. These data suggest that the biological effects of IL8 on MI risk may vary over time and warrant further cohort studies with repetitive IL8 measurements.     

Plasma levels of tissue plasminogen activator/plasminogen activator inhibitor-1 complex and von Willebrand factor are significant risk markers for recurrent myocardial infarction in the Stockholm Heart Epidemiology Program (SHEEP) study

An impaired fibrinolytic function due to elevated plasma levels of plasminogen activator inhibitor (PAI)-1 activity or tissue plasminogen activator (tPA) antigen is correlated with the development of myocardial infarction (MI) in patients with manifest coronary heart disease. Recently, methods for determining the specific tPA/inhibitor complexes constituting tPA antigen in plasma have become available. In the Stockholm Heart Epidemiology Program (SHEEP) study, 86 of 1212 MI patients, subjected to blood sampling in a metabolically stable period, suffered reinfarction before the end of 1996. These individuals have been compared with an approximately equal number of matched MI patients without recurrence and a group of matched healthy control subjects regarding the plasma concentrations of some hemostatic factors. The hemostatic compounds studied (fibrinogen, von Willebrand factor, tPA antigen, PAI-1, and the tPA/PAI-1 complex) were typically higher in the groups (men and women) with recurrence of MI compared with those without. The plasma concentrations were also typically higher in the pooled groups of patients compared with the groups of healthy control subjects. The largest between-group differences were found for the plasma tPA/PAI-1 complex. The crude odds ratio for reinfarction associated with higher concentration (>/=75th percentile among the control subjects) of tPA/PAI-1 was 1.8 (95% CI 1.1 to 3.1); the corresponding crude odds ratio for von Willebrand factor was 2.3 (1. 3 to 4.0). The tPA/PAI-1 complex correlated strongly with PAI-1 and tPA antigen in all groups and with serum triglycerides and body mass index in all groups except for women with reinfarction. An increased plasma level of tPA/PAI-1 complex is a novel risk marker for recurrent MI in men and women. Most likely, increased plasma levels of tPA/PAI-1 complex reflect impaired fibrinolysis, because the correlation with PAI-1 is strong. Further support is obtained indicating that the plasma concentration of von Willebrand factor is also an important risk marker for recurrent MI.     

Chocolate consumption and mortality following a first acute myocardial infarction: the Stockholm Heart Epidemiology Program

Objectives. To assess the long‐term effects of chocolate consumption amongst patients with established coronary heart disease. Design. In a population‐based inception cohort study, we followed 1169 non‐diabetic patients hospitalized with a confirmed first acute myocardial infarction (AMI) between 1992 and 1994 in Stockholm County, Sweden, as part of the Stockholm Heart Epidemiology Program. Participants self‐reported usual chocolate consumption over the preceding 12 months with a standardized questionnaire distributed during hospitalization and underwent a health examination 3 months after discharge. Participants were followed for hospitalizations and mortality with national registries for 8 years. Results. Chocolate consumption had a strong inverse association with cardiac mortality. When compared with those never eating chocolate, the multivariable‐adjusted hazard ratios were 0.73 (95% confidence interval, 0.41–1.31), 0.56 (0.32–0.99) and 0.34 (0.17–0.70) for those consuming chocolate less than once per month, up to once per week and twice or more per week respectively. Chocolate consumption generally had an inverse but weak association with total mortality and nonfatal outcomes. In contrast, intake of other sweets was not associated with cardiac or total mortality. Conclusions. Chocolate consumption was associated with lower cardiac mortality in a dose dependent manner in patients free of diabetes surviving their first AMI. Although our findings support increasing evidence that chocolate is a rich source of beneficial bioactive compounds, confirmation of this strong inverse relationship from other observational studies or large‐scale, long‐term, controlled randomized trials is needed.     

Sexual activity as a trigger of myocardial infarction. A case-crossover analysis in the Stockholm Heart Epidemiology Programme (SHEEP)

OBJECTIVE—To investigate sexual activity as a trigger of myocardial infarction and the potential effect modification of physical fitness.
DESIGN—A case-crossover study nested in the Stockholm Heart Epidemiology Programme (SHEEP).
SETTING—Stockholm County from April 1993 to December 1994.
PATIENTS—All patients with a first episode of non-fatal acute myocardial infarction admitted to coronary care units were eligible, and 699 patients participated in an interview.
MAIN OUTCOME MEASURES—Relative risks with 95% confidence intervals.
RESULTS—Only 1.3% of the patients without premonitory symptoms had sexual activity during two hours before the onset of myocardial infarction. The relative risk of myocardial infarction was 2.1 (95% confidence interval (CI) 0.7 to 6.5) during one hour after sexual activity, and the risk among patients with a sedentary life was 4.4 (95% CI 1.5 to 12.9).
CONCLUSIONS—The increased risk of myocardial infarction after sexual activity and the further increase in risk among the less physically fit support the hypothesis of causal triggering by sexual activity. However, the absolute risk per hour is very low, and exposure is relatively infrequent. Thus having sex once a week only increases the annual risk of myocardial infarction slightly. Counselling should focus on encouraging patients to live a physically active life and not on abstaining from sexual activity.


Keywords: myocardial infarction; sexual activity     

早发冠心病心肌梗死型与非心肌梗死型危险因素差异分析

目的探讨早发冠心病中心肌梗死型与非心肌梗死型的危险因素差异。方法回顾性分析2004年1月至2009年12月在沈阳医学院附属奉天医院心血管内科住院并确诊的45岁及以下冠心病患者165例,分为急性心肌梗死(AMI)组和非AMI组。对两组患者的相关临床资料及危险因素进行统计分析。结果 AMI组吸烟史比例、男性比率、血浆纤维蛋白原及D-二聚体均高于非AMI组,差异有统计学意义(P<0.05),两组的血脂异常率、血小板计数(PLT)、血小板压积、凝血酶原时间(PT)、国际标准化比值(INR)和活化部分凝血活酶时间(APTT)的差异无统计学意义。结论吸烟、男性性别、血脂水平异常是早发冠心病重要危险因素;血浆纤维蛋白原水平增高对于预测早发冠心病心肌梗死可能具有一定的临床意义。     

Hematocrit and risk of coronary heart disease: the Puerto Rico Heart Health Program

Hematocrit was determined in 2555 rural and 6151 urban men age 45 to 64 years participating in the Puerto Rico Heart Health Program, a prospective epidemiologic study of coronary artery disease (CAD). These participants were reexamined three additional times and mortality by cause and coronary heart disease (CHD) morbidity were carefully documented for 8 years of follow-up. Since hematocrit (Hct) is an indirect measure of blood viscosity, its value as an independent risk factor of CHD was evaluated. Within the Puerto Rican cohort, Hct is slightly lower in older age groups, and appears slightly lower in the rural than in the urban area. In the rural area 4.6% had Hct values below 40%; in the urban area 3.0% were below 40%. A higher Hct level was associated with cigarette smoking, higher relative weight, higher blood pressure, and higher serum cholesterol. An elevated Hct level was also associated with an increased risk of myocardial infarction (MI), coronary insufficiency or CHD death in the urban area. Incidence of MI, coronary insufficiency, or CHD death was more than double in the high hematocrit group (Hct > 49%) compared to the low group (Hct < 42%). Using a multivariate logistic function, the relationship remained statistically significant after adjustment for the above mentioned risk factors. These results provide further insight concerning the issue of the potential impact of elevated Hct as an independent risk factor contributing to the incidence of CHD mortality and morbidity.     

Trends in acute myocardial infarction coronary heart disease death in the United States

Coronary heart disease accounted for 489,171 deaths in 1990. Age-adjusted death rates decreased faster between 1976 and 1990 for white men than for white women or blacks. Out of hospital death rates for coronary heart disease decreased in the 1980s. Hospital fatality rates for acute myocardial infarction continued a long-term decrease through 1990. Trends in risk factors and invasive procedures support the conclusion that risk factor reduction has resulted in reduced incidence of acute myocardial infarction and sudden coronary death and that improvements in medical care have resulted in a continued decrease in acute myocardial infarction fatalities and overall coronary deaths.     

Type A score (Jenkins Activity Survey) and risk of recurrent coronary heart disease in the aspirin myocardial infarction study

The Jenkins Activity Survey (JAS), a questionnaire developed to assess the type A behavior pattern, was administered to 2,314 participants in the Aspirin Myocardial Infarction Study. All had a myocardial infarction (MI) before entering the study and were followed for at least 3 years. The JAS type A score was not significantly related to risk of recurrent major coronary events (definite nonfatal MI and coronary death) in the group of 244 women, the group of 2,070 men, or the subgroup of 671 men who were employed full-time in professional, technical or managerial positions. These results indicate that the JAS type A score is not useful in assessing prognosis after MI. By inference, traits measured by the JAS type A score, such as competitiveness, orientation toward achievement and preference for a rapid pace of life, appear not to be associated with increased risk of recurrent major coronary events.     

Serum homocysteine and long-term risk of myocardial infarction and sudden death in patients with coronary heart disease

We have prospectively evaluated the risk of incident coronary events in association with serum total homocysteine in patients with preexisting chronic coronary heart disease. A nested case-control design was used. Total homocysteine concentration was measured in baseline fasting serum samples from patients with chronic coronary heart disease enrolled in the Bezafibrate Infarction Prevention Study (n = 3,090) who developed coronary events during 6.2 years of follow-up (n = 69). They were matched for age and gender with controls without subsequent cardiovascular events. Elevated homocysteine levels were associated with 2.5 times higher risk of subsequent coronary events and each 5 mumol/l increment was associated with a 25% higher risk.     

Dietary magnesium intake and the future risk of coronary heart disease (the Honolulu Heart Program)

Magnesium (Mg) deficiency is believed to have adverse cardiovascular consequences that are broad and complex, although an association between dietary Mg intake and the risk of coronary heart disease (CHD) has not been clearly identified. The purpose of this study is to examine the relation between dietary Mg intake and future risk of CHD. Reported findings are based on dietary Mg intake in 7,172 men in the Honolulu Heart Program. Intake of Mg was recorded at baseline examinations that took place from 1965 to 1968 when the men were aged 45 to 68 years. In 30 years of follow-up, 1,431 incident cases of CHD were identified. Within 15 years after dietary assessment, the age-adjusted incidence decreased significantly from 7.3 to 4.0 per 1,000 person-years in the lowest (50.3 to 186 mg/day) versus highest (340 to 1,183 mg/day) quintiles of Mg intake (p <0.001). When adjustments were made for age and other nutrients (singly or combined), there was a 1.7- to 2.1-fold excess in the risk of CHD in the lowest versus highest quintiles (p <0.001). The excess risk ranged from 1.5- to 1.8-fold after further adjustment for other cardiovascular risk factors (p <0.05). Associations between dietary Mg and coronary events occurring after 15 years of follow-up were modest. We conclude that the intake of dietary Mg is associated with a reduced risk of CHD. Whether increases in dietary Mg intake can alter the future risk of disease warrants further study.     

Lipids and lipoproteins as risk factors for coronary heart disease in men with abnormal glucose tolerance: the Honolulu Heart Program

Abstract. Objectives. To evaluate lipids and lipoproteins as risk factors for coronary heart disease (CHD) in older men with non-insulin-dependent diabetes (NIDDM) or abnormal glucose tolerance compared with normoglycaemic men. Design. A prospective, population-based cohort study based on the lipoprotein examination (1970–72) of the Honolulu Heart Program. Follow-up was through to December 1988. Setting. Honolulu, Hawaii. Subjects. Japanese-American men, ages 51–72 at baseline: 2042 with 1 h glucose < 12.5 mmol l^?1 (normal group); 376 on oral hypoglycaemic agents or with 1 h glucose ≥ 12.5 mmol l^?1 after 50 g oral glucose challenge (abnormal glucose tolerance group). None had prevalent coronary heart disease (CHD) or stroke at baseline. Main outcome measures. Incident CHD: definite nonfatal myocardial infarction (MI) or fatal CHD. Results. There were 221 incident cases in the normal group, and 65 in the abnormal glucose tolerance group. Total and high-density lipoprotein (HDL) cholesterol were significant predictors of incident CHD in men with NIDDM or abnormal glucose tolerance after controlling for age, body-mass index, systolic blood pressure, pack-years of cigarettes and alcohol consumption (P < 0.05). Total, low-density lipoprotein (LDL) and very-low-density lipoprotein (VLDL) cholesterol were significant predictors in normal men, and HDL cholesterol was of borderline significance. Conclusions. Abnormal lipids and lipoproteins are significant, independent predictors of CHD in subjects with NIDDM or abnormal glucose tolerance. Attention to lipid and lipoproteins as CHD risk factors should be part of clinical management of these patients.     

Sweet and sour coronary heart disease: results from the China Heart Survey.

In 2002, Norhammar et al.¹ published the results of theoral glucose tolerance testing (OGTT) of 181 consecutive patientsadmitted to the coronary care unit because of acute myocardialinfarction (AMI) and without previously known diabetes. Amongthese patients, previously unknown diabetes and impaired glucosetolerance (IGT) were much more common than expected, 31 and35%, respectively. Equally high prevalences were detected whenthe OGTT was repeated 3 months after the event. This findingwas soon repeated in the large material of the Euro Heart Survey²and also extended to the patients with stable coronary heartdisease (CHD). Of the 923 patients with an acute CHD event,22% had newly detected diabetes and 36% IGT. Among the 997 patientswith stable CHD, 14% had newly detected diabetes and 37% IGT. It should be noted that 31%     

Family history of myocardial infarction as an independent risk factor for coronary heart disease

The hypothesis that a family history of heart attack before the age of 60 years is an independent risk factor for coronary heart disease was examined in a random sample of 1044 men aged 40-70. Data on personal and family history, smoking, weight, height, plasma lipid and lipoprotein concentrations, blood pressure, and resting and exercise electrocardiograms were collected according to the standard Lipid Research Clinics protocol. A history of heart attack in first degree relatives was ascertained by interviewing the participants. Evidence of coronary heart disease was found in 123 men (reported heart attack in 20, electrocardiographic findings of ischaemic heart disease at rest in 40, and electrocardiographic findings during heart rate limited exercise in 63). Subjects with coronary heart disease had considerably higher concentrations of total cholesterol, higher blood pressures, and lower concentrations of high density lipoprotein cholesterol than those without. Twenty nine per cent of the subjects with coronary heart disease reported a history of heart attack in a first degree relative before 60 years of age compared with 19% of those without. In a multivariate logistic model, the coefficients for age, cholesterol concentrations, and hypertension were all positive and statistically significant. The coefficient for HDL cholesterol concentration was negative and significant. A family history of heart attack showed a significant positive association, indicating a relation with coronary heart disease that is independent of the other variables in the model. The relation persisted in apparently asymptomatic patients with coronary heart disease.     

Myeloperoxidase is associated with incident coronary heart disease independently of traditional risk factors: results from the MONICA/KORA Augsburg study

Abstract. Karakas M, Koenig W, Zierer A, Herder C, Rottbauer W, Baumert J, Meisinger C, Thorand B (University of Ulm Medical Center, Ulm; German Research Center for Environmental Health, Institute of Epidemiology II, Neuherberg; and Institute for Clinical Diabetology, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany). Myeloperoxidase is associated with incident coronary heart disease independently of traditional risk factors: results from the MONICA/KORA Augsburg study. J Intern Med 2012; 271 : 43–50. Aims. Oxidative stress plays a critical role in the initiation and progression of atherosclerosis. Myeloperoxidase (MPO) is a marker of oxidative stress. We prospectively investigated whether an increased serum concentration of MPO is associated with an increased risk of incident coronary heart disease (CHD). Methods. We conducted a population‐based case‐cohort study in middle‐aged, healthy men and women within the MONICA/KORA Augsburg studies. Serum levels of MPO were measured in 333 subjects with (cases) and 1727 without (noncases) incident CHD. Mean follow‐up time was 10.8 ± 4.6 years. Results. Baseline concentrations of MPO were higher in cases compared with noncases (P ≤ 0.001 in men; P = 0.131 in women). After adjustment for major cardiovascular risk factors, the hazard ratio (HR) with 95% confidence interval (CI) comparing the top with the two lower tertiles was 1.70 (95% CI, 1.25–2.30). After additional adjustment for markers of inflammation and endothelial dysfunction, the association was attenuated (HR 1.50; 95% CI, 1.08–2.09). There were no significant interactions of MPO with sex or increased weight on CHD risk. Conclusions. Elevated concentrations of the oxidative stress marker MPO were independently associated with increased risk of incident CHD. This finding deserves detailed evaluation in further studies.