Omega-3 fatty acids in adipose tissue and risk of atrial fibrillation.

BACKGROUND: The aim of the present study was to examine the relation between adipose tissue content of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the risk of incident atrial fibrillation (AF). METHODS: In this case-cohort study based on data from the Danish Diet, Cancer and Health cohort, a total of 5255 incident cases of AF was identified during 16.9 years of follow-up. Adipose tissue biopsies collected at baseline from all cases and from a randomly drawn subcohort of 3440 participants were determined by gas chromatography. Data were analysed using weighted Cox regression. RESULTS: Data were available for 4741 incident cases of AF (2920 men and 1821 women). Participants in the highest vs. the lowest quintile of EPA experienced a 45% lower risk of AF (men HR 0.55 (95% CI 0.41-0.69); women HR 0.55 (0.41-0.72)). For DHA, no clear association was found in men, whereas in women, participants in the highest quintile of DHA in adipose tissue had a 30% lower risk of incident AF (HR 0.70 (0.54-0.91)) compared to participants in the lowest quintile. CONCLUSIONS: A monotonous inverse association was found for the content of EPA in adipose tissue and risk of AF in both men and women. The content of DHA was inversely associated with the risk of AF in women, whereas no clear association was found for men.

Is Cardiac Rehabilitation Equally Effective in Improving Dietary Intake in All Patients with Ischemic Heart Disease?

OBJECTIVE: To investigate the association between sociodemographic characteristics and changes in dietary intake in patients with ischemic heart disease who were following a cardiac rehabilitation program. METHODS: Longitudinal study among patients with first-time admission to outpatient cardiac rehabilitation after ST-elevation myocardial infarction, non-ST-elevation myocardial infarction, unstable angina pectoris or stable angina pectoris. We used a validated self-administered food frequency questionnaire to assess the dietary intake before rehabilitation, post rehabilitation and 6 months after baseline. The intake was summarized into a fat and fish-fruit-vegetable score for both sexes. To assess the within-patient differences in dietary scores, a paired t-test was applied. Regression analyses were performed to assess the association between sociodemographic characteristics and changes in diet. RESULTS: 186 patients completed two measurements, 157 patients completed all three measurements. Fat and fish-fruit-vegetable scores increased statistically significantly and improvements remained statistically significant at follow-up. Fat scores increased less in employed men than in retired men (-11 (95% CI -17; -5)). Fish-fruit-vegetable scores increased less in men with a bachelor degree than in men with a vocational education (-8 (95% CI -13; -3)) as well as in retired women compared with employed women (-18 (95% CI -32; -4)). CONCLUSIONS: Patients statistically significantly improved their dietary intake and improvements remained at follow-up. Dietary improvements were sensitive to marital status, living arrangements and employment status. Unemployed and retired women did not seem to improve their diet as much as employed women. Additional dietary intervention may become relevant in some patient groups defined by sociodemographic characteristics. (250).

Educational level and living arrangements are associated with dietary intake of red meat and fruit/vegetables: A Danish cross-sectional study.

Aims: To evaluate the association between education and living arrangements and the intake of fish, red meat and fruit and vegetables.Methods: The study design was cross-sectional and conducted in Denmark in 2013. Participants filled in questionnaires about their educational level and living arrangements (living alone or with others) and dietary intake including fish, red meat, fruit and vegetables. Regression analyses were performed to assess the associations within 85,456 randomly sampled healthy men and women who were at least 25 years old.Results: Length of education was statistically significant and positively associated with the intake of fruit and vegetables and negatively associated with the intake of red meat for both men and women. Men with a high level of education had a 187g/week (95% confidence interval: 199-175g/week) lower intake of red meat and a 109g/day (95% confidence interval: 102-117g/day) higher intake of fruit and vegetables than men with a low level of education. Women with a high level of education had a 175g/week (95% confidence interval: 186-164g/week) lower intake of red meat and a 106g/day (95% confidence interval: 97-114g/day) higher intake of fruit and vegetables than women with a low level of education. Living with others was statistically significant and positively associated with the intake of red meat, and fruit and vegetables. There were no clear associations between education, living arrangements and intake of fish.Conclusions: Men and women with a high educational level ate more fruit and vegetables but less red meat than men and women with a low educational level. Men and women living with others ate more red meat, fruit and vegetables than men and women living alone.

High Lipoprotein(a) May Explain One-Quarter of Clinical Familial Hypercholesterolemia Diagnoses in Danish Lipid Clinics.

CONTEXT: Cholesterol carried in lipoprotein(a) adds to measured low-density lipoprotein cholesterol (LDL-C) and may therefore drive some diagnoses of clinical familial hypercholesterolemia (FH). OBJECTIVE: We investigated plasma lipoprotein(a) in individuals referred to Danish lipid clinics and evaluated the effect of plasma lipoprotein(a) on a diagnosis of FH. METHODS: Individuals referred to 15 Danish lipid clinics who were suspected of having FH according to nationwide referral criteria were recruited between September 1, 2020 and November 30, 2021. All individuals were classified according to the Dutch Lipid Clinical Network criteria for FH before and after LDL-C was adjusted for 30% cholesterol content in lipoprotein(a). We calculated the fraction of individuals fulfilling a clinical diagnosis of FH partly due to elevated lipoprotein(a). RESULTS: We included a total of 1166 individuals for analysis, of whom 206 fulfilled a clinical diagnosis of FH. Median lipoprotein(a) was 15 mg/dL (29 nmol/L) in those referred and 28% had lipoprotein(a) greater than or equal to 50 mg/dL (105 nmol/L), while 2% had levels greater than or equal to 180 mg/dL (389 nmol/L). We found that in 27% (55/206) of those fulfilling a clinical diagnosis of FH, this was partly due to high lipoprotein(a). CONCLUSION: Elevated lipoprotein(a) was common in individuals referred to Danish lipid clinics and in one-quarter of individuals who fulfilled a clinical diagnosis of FH, this was partly due to elevated lipoprotein(a). These findings support the notion that the LPA gene should be considered an important causative gene in patients with clinical FH and further support the importance of measuring lipoprotein(a) when diagnosing FH as well as for stratification of cardiovascular risk.

Possible explanations for the common clinical familial hypercholesterolemia phenotypes in the Faroe Islands.

BACKGROUND: The prevalence of clinical familial hypercholesterolemia (FH) is very high in the Faroe Islands, but the possible causes are unknown. OBJECTIVES: We aimed to describe potential genetic causes of FH in the Faroe Islands and to investigate whether levels of lipoprotein(a) and measures of dietary habits were associated with clinical FH in the Faroe Islands. METHODS: In this case-control study, we identified potential clinical FH cases aged 18-75 years registered within a nationwide clinical laboratory database in the Faroe Islands and invited them for diagnostic evaluation according to clinical FH scoring systems. Controls were identified in the background population. Lipoprotein(a) was measured in plasma, while the fatty acid composition was determined in adipose tissue. The habitual diet of the participants was assessed using a food frequency questionnaire. Genetic testing for FH and polygenic variants was performed in a selection of clinical FH cases. RESULTS: A total of 121 clinical FH cases and 123 age- and sex-matched controls were recruited. We found a very low frequency of monogenic FH (2.5%), but a high level of polygenic FH (63%) in those genetically tested (67%). High levels of plasma lipoprotein(a) were associated with high odds of clinical FH. Clinical FH cases had a lower intake of saturated fatty acids (SFAs) measured by a high fat-score and a lower content of SFAs in adipose tissue compared with controls. CONCLUSION: The high prevalence of FH in the Faroe Islands may be due to polygenic causes of hypercholesterolemia and to a lesser extent other genetic factors and elevated plasma lipoprotein(a) levels.

The Danish Atrial Fibrillation Registry: A Multidisciplinary National Pragmatic Initiative for Monitoring and Supporting Quality of Care Based on Data Retrieved from Administrative Registries.

Aim: The Danish Atrial Fibrillation (AF) Registry monitors and supports improvement of quality of care for all AF patients in Denmark. This report describes the registry's administrative and organizational structure, data sources, data flow, data analyses, annual reporting, and feedback between the registry, clinicians, and the administrative system. We also report the selection process of the quality indicators and the temporal trends in results from 2017-2021. Methods and Results: The Danish AF Registry aims for complete registration and monitoring of care for all patients diagnosed with AF in Denmark. Administrative registries provide data on contacts to general practice, contacts to private cardiology practice, hospital contacts, medication prescriptions, updated vital status information, and biochemical test results. The Danish Stroke Registry provides information on stroke events. From 2017 to 2021, the proportion with a reported echocardiography among incident AF patients increased from 39.9% (95% CI: 39.3-40.6) to 82.6% (95% CI: 82.1-83.1). The initiation of oral anticoagulant therapy among patients with incident AF and a CHA2DS2-VASc score of ≥1 in men and ≥2 in women increased from 85.3% (95% CI: 84.6-85.9) to 90.4% (95% CI: 89.9-91.0). The 1-year and 2-year persistence increased from 85.2% (95% CI: 84.5-85.9) to 88.7% (95% CI: 88.0-89.3), and from 85.4% (95% CI: 84.7-86.2) to 88.2% (95% CI: 87.5-88.8), respectively. The 1-year risk of ischemic stroke among prevalent patients with AF decreased from 0.88% (95% CI: 0.83-0.93) to 0.71% (95% CI: 0.66-0.75). Variation in clinical performance between the five administrative Danish regions was reduced. Conclusion: Continuous nationwide monitoring of quality indicators for AF originating from administrative registries is feasible and supportive of improvements of quality of care.

Genetic testing increases the likelihood of a diagnosis of familial hypercholesterolaemia among people referred to lipid clinics: Danish national study.

BACKGROUND AND AIMS: It is unclear to what extent genetic testing improves the ability to diagnose familial hypercholesterolaemia (FH). We investigated the percentage with FH among individuals referred to Danish lipid clinics, and evaluated the impact of genetic testing for a diagnosis of FH. METHODS: From September 2020 through November 2021, all patients referred for possible FH to one of the 15 Danish lipid clinics were invited for study participation and >97% (n = 1488) accepted. The Dutch Lipid Clinical Network criteria were used to diagnose clinical FH. The decision of genetic testing for FH was based on local practice. RESULTS: A total of 1243 individuals were referred, of whom 25.9% were diagnosed with genetic and/or clinical FH. In individuals genetically tested (n = 705), 21.7% had probable or definite clinical FH before testing, a percentage that increased to 36.9% after genetic testing. In individuals with unlikely and possible FH before genetic testing, 24.4% and 19.0%, respectively, had a causative pathogenic variant. CONCLUSIONS: In a Danish nationwide study, genetic testing increased a diagnosis of FH from 22% to 37% in patients referred with hypercholesterolaemia suspected of having FH. Importantly, approximately 20% with unlikely or possible FH, who without genetic testing would not have been considered having FH (and family screening would not have been undertaken), had a pathogenic FH variant. We therefore recommend a more widespread use of genetic testing for evaluation of a possible FH diagnosis and potential cascade screening.

Marine n-3 polyunsaturated fatty acids in adipose tissue and the risk of acute coronary syndrome.

BACKGROUND: Marine n-3 polyunsaturated fatty acids may reduce coronary mortality. Previous data in relation to nonfatal coronary disease, however, have been inconsistent, which may be explained by the use of heterogeneous methods to assess the intake of marine n-3 polyunsaturated fatty acids. We investigated the hypothesis that the content of total and individual marine n-3 polyunsaturated fatty acids in adipose tissue is negatively associated with the incidence of acute coronary syndrome (ACS), including both fatal and nonfatal coronary disease. METHODS AND RESULTS: In the Diet, Cancer and Health, a Danish cohort study, 57 053 subjects were enrolled and had an adipose tissue biopsy taken at inclusion. During a mean follow-up period of 7.6 years, we identified and verified all cases (n=1012) with an incident acute coronary syndrome diagnosis, and a random sample of the cohort (n=1630) had their fatty acid composition in adipose tissue determined by gas chromatography. We found negative dose-response associations between the content of total marine n-3 polyunsaturated fatty acids and individual n-3 polyunsaturated fatty acids in adipose tissue and the risk of acute coronary syndrome. Comparing men in the highest and lowest quintiles gave a hazard ratio of 0.65 (95% confidence interval, 0.45 to 0.95) for total n-3 polyunsaturated fatty acids and 0.51 (95% confidence interval, 0.36 to 0.73) for docosahexaenoic acid. Nonfatal cases constituted >86% of cases, and the association was driven primarily by a reduction in the risk of nonfatal acute coronary syndrome. No consistent associations were found among women. CONCLUSION: Intake of marine n-3 polyunsaturated fatty acids may protect against acute coronary syndrome in men.

Validity of the diagnoses atrial fibrillation and atrial flutter in a Danish patient registry.

OBJECTIVES: To assess the validity of the diagnoses of atrial fibrillation (AF) and atrial flutter (AFL) for men and women recorded in the Danish National Patient Registry, and to assess the relative distribution of AF and AFL. DESIGN: Review of medical records for incident cases of AF and/or AFL in the Diet, Cancer, and Health cohort study. Participants were enrolled in 1993-97 with 13.6 years of follow-up until 30 December, 2009. RESULTS: The positive predictive value of the combined diagnosis of AF and/or AFL was 92.6% (95% CI 88.8%; 95.2%) with no significant difference between sexes (men 93.7% (133/142), women 90.8% (129/142)). The proportion of AFL either alone or in combination with AF was significantly higher in men than in women (13.5% (18/133) vs. 5.4% (7/129), p =0.03). The positive predictive value of the specified diagnosis of AFL was 57.5% for men (46/80) and 29.6% for women (8/27). CONCLUSIONS: This study shows that the validity of the diagnosis of AF and/or AFL is high and may be used for registry-based studies. A specified diagnosis of AFL was rarely used and was not reliable to distinguish between cases of AF and AFL.

Association Between Newly Diagnosed Atrial Fibrillation and Work Disability (from a Nationwide Danish Cohort Study).

It is previously shown that cardiovascular conditions have a negative effect on the ability to work. However, it is unknown if incident atrial fibrillation (AF) influences the ability to work. We examined the association between AF and the risk of work disability and the influence of socioeconomic factors. All Danish residents with a hospital diagnosis of AF and aged ≥30 and ≤63 years in the period January 1, 2000, to September 31, 2014, were included and matched 1:10 with an AF-free gender and age-matched random person from the general population. Permanent social security benefit was used as a marker of work disability. Risk difference (RD) and 95% confidence interval (95% CI) of work disability were calculated over 15 months. The analyses were furthermore stratified in low, medium, and high levels of socioeconomic factors. In total, 28,059 patients with AF and 312,667 matched reference persons were included. The risk of receiving permanent social security benefits within 15 months was 4.5% (4.3% to 4.8%) for the AF cohort and 1.3% (95% CI 1.3% to 1.4%) for the matched reference cohort. Adjusted RD (95% CI) was 2.3% (2.0% to 2.5%). Stratified on income, RDs were higher in low-income groups (adjusted RD 3.7% [95% CI 3.1% to 4.3%]) versus high-income groups (RD 1.3% [1.0% to 1.5%]). In conclusion, the risk of work disability within 15 months after incident AF was more than 3 times as high in patients with AF compared with the general population, especially when comparing individuals in lower socioeconomic strata.

Quantifying benefits of the Danish transfat ban for coronary heart disease mortality 1991-2007: Socioeconomic analysis using the IMPACTsec model.

Denmark has experienced a remarkable reduction in CVD mortality over recent decades. The scale of the health contribution from the Danish regulation on industrially produced trans fatty acid (ITFA) has therefore long been of interest. Thus the objective was to determine health and equity benefits of the Danish regulation on ITFA content in Danish food, by quantifying the relative contributions of changes in ITFA intake, other risk factors and treatments on coronary heart disease (CHD) mortality decline from 1991 to 2007 in Denmark, stratified by socioeconomic group. To evaluate the effects of the ITFA ban (Danish Order no. 160 of March 2003) the Danish IMPACTSEC model was extended to quantify reductions in CHD deaths attributable to changes in ITFA (%E) intake between 1991-2007. Population counts were obtained from the Danish Central Office of Civil Registration, financial income from Statistics Denmark and ITFA intake from Dan-MONICA III (1991) and DANSDA (2005-2008). Participants were adults aged 25-84 years living in Denmark in 1991 and 2007, stratified by socioeconomic quintiles. The main outcome measure was CHD deaths prevented or postponed (DPP). Mean energy intake from ITFA was decimated between 1991 and 2007, falling from 1.1%E to 0.1%E in men and from 1·0%E to 0·1%E in women. Approximately 1,191 (95% CI 989-1,409) fewer CHD deaths were attributable to the ITFA reduction, representing some 11% of the overall 11,100 mortality fall observed in the period. The greatest attributable mortality falls were seen in the most deprived quintiles. Adding ITFA data to the original IMPACTsec model improved the overall model fit from 64% to 73%. In conclusion: Denmark's mandatory elimination of ITFA accounted for approximately 11% of the substantial reduction in CHD deaths observed between 1991 and 2007. The most deprived groups benefited the most, thus reducing inequalities. Adopting the Danish ITFA regulatory approach elsewhere could substantially reduce CHD mortality while improving health equity.

Lipids, lipoproteins and prevalence of familial hypercholesterolemia in the Faroe Islands - Results from a nationwide laboratory database.

Background and aims: Familial hypercholesterolemia (FH) is one of the most common hereditary disorders. The population of the Faroe Islands was established by few founders, and genetic drift may have influenced lipid levels. The aim of this study was to describe the lipid distribution by providing age and sex-specific lipid values and to investigate the prevalence of FH in the Faroe Islands. Methods: We used an electronic nationwide laboratory database that included lipid measurements obtained in the Faroe Islands between January 2006 and September 2020. Percentiles of lipid levels were calculated using quantile regression. The prevalence of FH was estimated according to the Make Early Diagnosis Prevent Early Death (MEDPED) diagnostic criteria and according to the LDL-C cut-off levels included in the Dutch Lipid Clinic Network (DLCN) criteria using generalized linear models with robust variance. Results: According to the MEDPED age-specific cut-offs for LDL-C, a total of 216 subjects met the criteria for definite FH among 30,711 individuals corresponding to a prevalence of 0.70% (1:142). According to the LDL-C cut-offs included in the DLCN criteria, a total of 3,823 (1:8) subjects could be classified as having possible FH, and 10 (1:3,071) subjects could be classified as probable FH corresponding to a prevalence of 12.4% and 0.03%, respectively. Also, we found significant differences in lipid levels according to sex and age groups. Conclusion: The Faroe Islands might represent a founder population with a prevalence of possible FH as high as 1 in 8. Further investigation of genetic and clinical characteristics of FH in the Faroe Islands is needed.

Familial hypercholesterolaemia: a study protocol for identification and investigation of potential causes and markers of subclinical coronary artery disease in the Faroe Islands.

INTRODUCTION: Familial hypercholesterolaemia (FH) is the most common monogenic autosomal dominant genetic disorder and is associated with a high risk of premature atherosclerotic cardiovascular disease. The prevalence of FH has been reported to be particularly high in certain founder populations. The population of the Faroe Islands is a founder population, but the prevalence of FH has never been investigated here. We aim to assess the prevalence of FH and to describe the genetic and clinical characteristics and potential causes of FH in the Faroe Islands. Furthermore, we aim to investigate whether indicators of subclinical coronary artery disease are associated with FH. METHODS AND ANALYSIS: The prevalence of FH will be estimated based on an electronic nationwide laboratory database that includes all measurements of plasma lipid levels in the Faroe Islands since 2006. Subsequently, we will identify and invite subjects aged between 18 and 75 years registered with a plasma low-density lipoprotein cholesterol above 6.7 mmol/L for diagnostic evaluation. Eligible FH cases will be matched to controls on age and sex. We aim to include 120 FH cases and 120 controls.Detailed information will be collected using questionnaires and interviews, and a physical examination will be undertaken. An adipose tissue biopsy and blood samples for genetic testing, detailed lipid analyses and samples for storage in a biobank for future research will be collected. Furthermore, FH cases and controls will be invited to have a transthoracic echocardiography and a cardiac CT performed. ETHICS AND DISSEMINATION: The project has been approved by the Ethical Committee and the Data Protection Agency of the Faroe Islands. The project is expected to provide important information, which will be published in international peer-reviewed journals.

Subclinical atherosclerosis determined by coronary artery calcium deposition in patients with clinical familial hypercholesterolemia.

Background and aims: Limited knowledge exists regarding the association between coronary artery calcium (CAC) deposition in patients with clinical familial hypercholesterolemia (FH) and FH subtypes such as polygenic causes. We studied CAC score in patients with clinical FH and subtypes including polygenic causes of FH compared to healthy controls. Methods: In a case-control study, we identified potential clinical FH cases registered with an LDL-C >6.7 mmol/l within a nationwide clinical laboratory database on the Faroe Islands and invited them for diagnostic evaluation according to clinical FH scoring systems. Controls were identified in the background population. All subjects were aged 18-75 years and without a history of cardiovascular disease. FH mutation testing and genotypes of twelve LDL-C associated single nucleotide polymorphisms were determined using conventional methods in selected individuals. CAC scores were assessed by cardiac CT. Odds ratios obtained using multivariate logistic regression were used as measures of association. Results: A total of 120 clinical FH patients and 117 age- and sex-matched controls were recruited. We found a very low frequency of monogenic FH (3%), but a high level of polygenic FH (60%) in those genetically tested (54%). There was a statistically significant association between the CAC score and a diagnosis of clinical FH with the highest observed odds ratio of 5.59 (95% CI 1.65; 18.94, p = 0.006) in those with a CAC score ≥300 compared to those with a CAC of zero. In supplemental analyses, there was a strong association between CAC scores and clinical FH of a polygenic cause. Conclusion: We found a statistically significant association between CAC levels and clinical FH with the highest observed risk estimates among clinical FH cases of a presumed polygenic cause.

Socioeconomic inequality in oral anticoagulation therapy initiation in patients with atrial fibrillation with high risk of stroke: a register-based observational study.

OBJECTIVE: The study aimed to examine the association between socioeconomic factors (SEFs) and oral anticoagulation (OAC) therapy and whether it was influenced by changing guidelines. We hypothesised that inequities in initiation of OAC reduced over time as more detailed and explicit clinical guidelines were issued. DESIGN: Register-based observational study. SETTINGS: All Danish patients with an incident hospital diagnosis of atrial fibrillation (AF), aged ≥30 years old and with high risk of stroke from 1 May 1999 to 2 October 2015 were included. Absolute risk differences (RD) (95% CI) were used to measure the association. PARTICIPANTS: 154 448 patients (mean age 78.2 years, men 47.3%). EXPOSURE: Education, family income and cohabiting status were the SEFs used as exposure. OUTCOME: A prescription of OAC within -30 to +90 days of baseline (incident AF). RESULTS: During 2002-2007, the crude RD of initiation of OAC for men with high education was 14.9% (12.8 to 16.9). Inequality reduced when new guidelines were published, and in 2013-2016 the crude RD was 5.6% (3.5 to 7.7). After adjusting for age, the RD substantially reduced. The same pattern was seen for cohabiting status, while inequality was smaller and more constant for income. CONCLUSION: Patients with low income, low education and living alone were associated with lower chance of being initiated with OAC. For education and cohabiting status, the crude difference reduced around 2011, when more detailed clinical guidelines were implemented in Denmark. Our results indicate that new guidelines might reduce inequality in OAC initiation and that new, high-cost drugs increase inequality.

Alcohol drinking habits, alcohol dehydrogenase genotypes and risk of acute coronary syndrome.

AIMS: The risk of myocardial infarction is lower among light-to-moderate drinkers compared with abstainers. Results from some previous studies, but not all, suggest that this association is modified by variations in genes coding for alcohol dehydrogenase (ADH). We aimed to test this hypothesis, including alcohol as both the amount of alcohol and the frequency of drinking. METHODS: we conducted a nested case-cohort study within the Danish Diet, Cancer and Health study, including 1,645 men (770 incident cases of acute coronary syndrome from 1993-1997 through 2004 and 875 randomly selected controls). RESULTS: Higher alcohol intake (measured as amount or drinking frequency) was associated with lower risk of acute coronary syndrome; however, there was no evidence that these finding were modified by ADH1B or ADH1C genotypes. CONCLUSIONS: The importance of functional variation in alcohol dehydrogenase for the association between alcohol drinking habits and the risk of developing acute coronary syndrome, if any, is very limited.

Socioeconomic position and risk of atrial fibrillation: a nationwide Danish cohort study.

AIM: To examine the association between socioeconomic position and the risk of atrial fibrillation (AF) in different stages of life in a population of Danish citizens. METHODS: Register-based study. We followed all individuals turning 35, 50, 65 or 80 years from 1 January 1996 to 31 December 2005 until AF, death, emigration or the end of study period (31 December 2015). Exposure was education and income. We used Cox regression for the HRs (95% CI) and the pseudo-observation method for the adjusted risk difference (RD) (%). RESULTS: A total of 2 173 857 participants were enrolled and 151 340 incident cases of AF occurred over a median of 13.6 years of follow-up. Adjusted HR (95% CI) of incident AF for the youngest age group with the highest education (ref lowest) was 0.62 (0.50 to 0.77) (women) and 0.85 (0.76 to 0.96) (men). The associations attenuated with increasing age, that is, HRs for the oldest age group were 1.04 (0.97 to 1.10) and 0.98 (0.96 to 1.04), respectively. The corresponding adjusted RDs (%) were: -0.28 (-0.43 to -0.14), -0.18 (-0.36 to -0.01), 3.04 (-0.55 to 6.64) and -0.74 (-3.38 to 2.49), respectively. Similar but weaker associations were found for income. CONCLUSION: Higher level of education and income was associated with a lower risk of being diagnosed with AF in young individuals but the association decreased with increasing age and was almost absent for the oldest age cohort. However, since AF is relatively rare in the youngest the RDs were low.

The validity of the diagnosis of heart failure (I50.0-I50.9) in the Danish National Patient Register.

INTRODUCTION: National discharge registers are important and cost-effective data sources for administrative and research purposes, but their value depends much on the validity of the registered data. The objective of this study was to assess the validity of heart failure (HF) diagnoses (ICD10: I50.0-I50.9) in the Danish National Patient Register (DNPR). METHODS: We reviewed medical records from a random sample of 500 patients with either a primary or a secondary discharge diagnosis of HF registered in the DNPR from any department in Northern Denmark in 2007. We noted symptoms, objective signs, diagnostic imaging and biomarkers and used the European Society of Cardiology definition of HF to categorise patients into definite, probable or non-verified HF. RESULTS: We classified 305 patients as having definite HF and 113 patients as having probable HF. The remaining cases were classified as non-verified HF. Thus, the positive predictive value (PPV) for definite and probable HF was 83.6% (95% confidence interval (CI): 80.1-86.7%).
The PPV increased to 88.0% (95% CI: 84.4-91.0%) when we restricted analyses to primary diagnoses and to 95.2% (95% CI: 89.2-98.4%) when we restricted analyses to HF diagnoses established at cardiology units. CONCLUSIONS: The HF diagnoses (I50.0-I50.9) in the DNPR should be used with caution if validation is not possible. However, restricting analyses to patients registered with a primary diagnosis of HF or patients discharged from cardiology units may be a useful alternative in population-based studies. FUNDING: none. TRIAL REGISTRATION: not relevant.

Associations between socioeconomic status, atrial fibrillation, and outcomes: a systematic review.

BACKGROUND: Atrial fibrillation (AF) is a growing epidemic and evidence of a relationship to socioeconomic status (SES) is inconsistent. We aimed to summarize the literature about SES and AF and defined two objectives: (1) To examine the association between SES and the risk of AF; (2) To examine the association between SES and AF-related outcomes in an AF-population. METHODS: We performed a separate search for each objective in Ovid-MEDLINE and Ovid-Embase. For objective 1, the population included was healthy participants and outcome of interest was AF. For objective 2, the population included were patients with AF and outcome of interest was mortality, treatment, ablation for AF, knowledge about AF, and morbidity. RESULTS: For objective 1, 12 studies were included. No consistent pattern for an association between SES and the risk of AF was discovered. For objective 2, 39 studies comprising 42 outcomes were included. The majority of studies showed an association between low SES and increased mortality and morbidity. CONCLUSION: Low SES was associated with poorer outcomes when AF was present. These findings may imply that health-care professionals and policy interventions should focus on the promotion of AF-education and management among patients with AF and low SES.