Predictive value of stroke discharge diagnoses in the Danish National Patient Register

Use of Latent Class Analysis to Predict Intensive Care Unit Admission and Mortality in Children with a Major Congenital Anomaly

OBJECTIVE

To define major congenital anomaly (CA) subgroups and assess outcome variability based on defined subgroups.

STUDY DESIGN

This population-based cohort study used registries in Denmark for children born with a major CA between January 1997 and December 2016, with follow-up until December 2018. We performed a latent class analysis (LCA) using child and family clinical and sociodemographic characteristics present at birth, incorporating additional variables occurring until age of 24 months. Cox proportional hazards regression models estimated hazard ratios (HRs) of pediatric mortality and intensive care unit (ICU) admissions for identified LCA classes.

RESULTS

The study included 27 192 children born with a major CA. Twelve variables led to a 4-class solution (entropy = 0.74): (1) children born with higher income and fewer comorbidities (55.4%), (2) children born to young mothers with lower income (24.8%), (3) children born prematurely (10.0%), and (4) children with multiorgan involvement and developmental disability (9.8%). Compared with those in Class 1, mortality and ICU admissions were highest in Class 4 (HR = 8.9, 95% CI = 6.4-12.6 and HR = 4.1, 95% CI = 3.6-4.7, respectively). More modest increases were observed among the other classes for mortality and ICU admissions (Class 2: HR = 1.7, 95% CI = 1.1-2.5 and HR = 1.3, 95% CI = 1.1-1.4, respectively; Class 3: HR = 2.5, 95% CI = 1.5-4.2 and HR = 1.5, 95% CI = 1.3-1.9, respectively).

CONCLUSIONS

Children with a major CA can be categorized into meaningful subgroups with good discriminative ability. These groupings may be useful for risk-stratification in outcome studies.

A systematic evaluation of seven different scores representing the EAT-Lancet reference diet and mortality, stroke, and greenhouse gas emissions in three cohorts

Different approaches have been used for translation of the EAT-Lancet reference diet into dietary scores that can be used to assess health and environmental impact. Our aim was to compare the different EAT-Lancet diet scores, and to estimate their associations with all-cause mortality, stroke incidence, and greenhouse gas emissions. We did a systematic review (PROSPERO, CRD42021286597) to identify different scores representing adherence to the EAT-Lancet reference diet. We then qualitatively compared the diet adherence scores, including their ability to group individuals according the EAT-Lancet reference diet recommendations, and quantitatively assessed the associations of the diet scores with health and environmental outcome data in three diverse cohorts: the Danish Diet, Cancer and Health Cohort (DCH; n=52 452), the Swedish Malmö Diet and Cancer Cohort (MDC; n=20 973), and the Mexican Teachers' Cohort (MTC; n=30 151). The DCH and MTC used food frequency questionnaires and the MDC used a modified diet history method to assess dietary intake, which we used to compute EAT-Lancet diet scores and evaluate the associations of scores with hazard of all-cause mortality and stroke. In the MDC, dietary greenhouse gas emission values were summarised for every participant, which we used to predict greenhouse gas emissions associated with varying diet adherence scores on each scoring system. In our review, seven diet scores were identified (Knuppel et al, 2019; Trijsburg et al, 2020; Cacau et al, 2021; Hanley-Cook et al, 2021; Kesse-Guyot et al, 2021; Stubbendorff et al, 2022; and Colizzi et al, 2023). Two of the seven scores (Stubbendorff and Colizzi) were among the most consistent in grouping participants according to the EAT-Lancet reference diet recommendations across cohorts, and higher scores (greater diet adherence) were associated with decreased risk of mortality (in the DCH and MDC), decreased risk of incident stroke (in the DCH and MDC for the Stubbendorff score; and in the DCH for the Colizzi score), and decreased predicted greenhouse gas emissions in the MDC. We conclude that the seven different scores representing the EAT-Lancet reference diet had differences in construction, interpretation, and relation to disease and climate-related outcomes. Two scores generally performed well in our evaluation. Future studies should carefully consider which diet score to use and preferably use multiple scores to assess the robustness of estimations, given that public health and environmental policy rely on these estimates.

Cancer risk in patients with rheumatoid arthritis treated with janus kinase inhibitors: a nationwide Danish register-based cohort study

OBJECTIVES

We aimed to investigate the risk of first primary cancer in patients with RA treated with janus kinase inhibitors (JAKi) compared with those who received biologic DMARDs (bDMARDs) in a real-world setting.

METHODS

We performed an observational cohort study using the nationwide registers in Denmark. Patients with RA aged 18+ years, without a previous cancer diagnosis, and who initiated treatment with JAKi or bDMARDs from 1 January 2017 to 31 December 2020 were followed for any cancer (except non-melanoma skin cancer). We applied inverse probability of treatment weighting (IPTW) to account for covariate differences between treatment groups. IPTW-generated weights were used with cause-specific Cox (CSC) models to calculate hazard ratios (HRs) for cancer incidence in JAKi-treated compared with bDMARD-treated patients with RA.

RESULTS

We identified 875 and 4247 RA patients treated with JAKi and bDMARDs, respectively. The JAKi group contributed 1315 person years (PYRS) and 19 cancers, the bDMARD group contributed 8597 PYRS and 111 cancers, with corresponding crude incidence rates per 1000 PYRS of 14.4 and 12.9. Comparing the two groups using weighted CSC models, a HR of 1.41 (95% CI 0.76, 2.37, 95% CIs) was seen for JAKi- vs bDMARD-treated patients with RA.

CONCLUSION

JAKi treatment in real-world patients with RA was not associated with a statistically significant increased risk of first primary cancer compared with those who received bDMARDs. However, several numerically increased risk estimates were detected, and a clinically important excess risk of cancer among JAKi recipients cannot be dismissed.

Validity of Routine Health Data To Identify Safety Outcomes of Interest For Covid-19 Vaccines and Therapeutics in the Context of the Emerging Pandemic: A Comprehensive Literature Review

Introduction

Regulatory guidance encourages transparent reporting of information on the quality and validity of electronic health record data being used to generate real-world benefit-risk evidence for vaccines and therapeutics. We aimed to provide an overview of the availability of validated diagnostic algorithms for selected safety endpoints for Coronavirus disease 2019 (COVID-19) vaccines and therapeutics in the context of the emerging pandemic prior to December 2020.

Methods

We reviewed the literature up to December 2020 to identify validation studies for various safety events of interest, including myocardial infarction, arrhythmia, myocarditis, acute cardiac injury, vasculitis/vasculopathy, venous thromboembolism, stroke, respiratory distress syndrome (RDS), pneumonitis, cytokine release syndrome (CRS), multiple organ dysfunction syndrome, and renal failure. We included studies published between 2015 and 2020 that were considered high quality assessed with QUADAS and that reported positive predictive values (PPVs).

Results

Out of 43 identified studies, we found that diagnostic algorithms for cardiovascular outcomes were supported by the highest number of validation studies (n=17). Accurate algorithms are available for myocardial infarction (median PPV 80%; IQR 22%), arrhythmia (PPV range >70%), venous thromboembolism (median PPV: 73%) and ischaemic stroke (PPV range ≥85%). We found a lack of validation studies for less common respiratory and cardiac safety outcomes of interest (eg, pneumonitis and myocarditis), as well as for COVID-specific complications (CRS, RDS).

Conclusion

There is a need for better understanding of barriers to conducting validation studies, including data governance restrictions. Regulatory guidance should promote embedding validation within real-world EHR research used for decision-making.

Association between Glucose-lowering Treatments and Risk of Diabetic Retinopathy in People with Type 2 Diabetes: A Nationwide Cohort Study

INTRODUCTION

Glycaemic variability is possibly linked to the development of diabetic retinopathy, and newer second-line glucose-lowering treatments in type 2 diabetes might reduce glycaemic variability.

AIM

This study aimed to investigate whether newer second-line glucose-lowering treatments are associated with an alternative risk of developing diabetic retinopathy in people with type 2 diabetes.

METHODS

A nationwide cohort of people with type 2 diabetes on second-line glucose-lowering treatment regimens in 2008-2018 was extracted from the Danish National Patient Registry. Adjusted time to diabetic retinopathy was estimated with a Cox Proportional Hazards model. The model was adjusted for age, sex, diabetes duration, alcohol abuse, treatment start year, education, income, history of late-diabetic complications, history of non-fatal major adverse cardiovascular events, history of chronic kidney disease, and history of hypoglycaemic episodes.

RESULTS

Treatment regimens of metformin + basal insulin (HR: 3.15, 95% CI: 2.42-4.10) and metformin + glucagon-like peptide-1 receptor agonist (GLP-1-RA, HR: 1.46, 95% CI: 1.09-1.96) were associated with an increased risk of diabetic retinopathy compared with metformin + dipeptidyl peptidase-4 inhibitors (DPP-4i). Treatment with metformin + sodium-glucose cotransporter-2 inhibitor (SGLT2i, HR: 0.77, 95% CI: 0.28-2.11) was associated with the numerically lowest risk of diabetic retinopathy compared with all regimens investigated.

CONCLUSION

Findings from this study indicate that basal insulin and GLP-1-RA are suboptimal second- line choices for people with type 2 diabetes at risk of developing diabetic retinopathy. However, many other considerations concerning the choice of second-line glucose-lowering treatment for type 2 diabetes patients should be taken into account.

Parental cardiovascular disease and cardiovascular disease risk factors in the offspring: The Diet, Cancer and Health cohorts

BACKGROUND AND AIMS

Cardiovascular disease (CVD) aggregates in families and offspring with parental CVD may have adverse risk factor levels long time before the potential onset of CVD. We compared risk factor levels in offspring of parents with atherosclerotic CVD (ASCVD) and parents with no ASCVD at different parental ages at onset.

METHODS

The study included 5751 participants (median age: 50 years) of the Diet, Cancer and Health - Next Generations study. Measurements included blood pressure, body composition and lipid fractions. Information on parental ASCVD and age at disease onset was obtained through register linkage. Parental ASCVD was defined as myocardial infarction, ischemic stroke or peripheral artery disease occurring <70 years, prematurely (mothers: <65 years fathers: <55 years), divided into age categories or using a broader classification of CVD. Linear regression models using Generalized Estimating Equations were used for analysis. Analyses were adjusted for age, sex, education, smoking, alcohol intake, physical activity and some additionally for BMI.

RESULTS

Offspring with parental ASCVD had a higher blood pressure, waist circumference, BMI, visceral adipose tissue, percentage of body fat and non-HDL cholesterol levels, but not other lipid levels, compared to offspring with no parental ASCVD (all p < 0.01). Overall, the same patterns were observed for parental ASCVD occurring prematurely and using a broader CVD classification.

CONCLUSIONS

Offspring with parental ASCVD had a higher blood pressure, higher body composition measures and higher non-HDL cholesterol levels compared to offspring with no parental ASCVD. Findings were overall consistent across different classifications of parental ASCVD.

Risk of diabetes and cardiovascular diseases in women with vaginal bleeding before 20 gestational weeks: Danish population-based cohort study

BACKGROUND

Women's reproductive health is associated with cardiovascular morbidity. However, an association of vaginal bleeding (VB) in pregnancy with diabetes and cardiovascular outcomes has scarcely been investigated.

METHODS

We conducted a population-based cohort study in Denmark (1994-2018). Using nationwide registries, among 903 327 women we identified 1 901 725 pregnancies: 39 265 ended in childbirth and were affected by VB; 1 389 285 ended in childbirth and were unaffected by VB; 333 785 ended in a termination, and 139 390 ended in a miscarriage. The outcomes were diabetes types 1 and 2, hypertension, ischaemic heart disease including myocardial infarction, atrial fibrillation or flutter, heart failure and ischaemic and haemorrhagic stroke. We computed incidence rates and hazard ratios (HRs) with 95% confidence intervals (CIs) adjusted for age, calendar year of pregnancy end, morbidities and reproductive and socioeconomic factors, using inverse probability of treatment-weighted Cox proportional hazards regression.

RESULTS

In analyses of VB-affected vs VB-unaffected pregnancies, aHRs were 1.15 (1.03-1.28) for diabetes type 1, 1.19 (1.13-1.26) for diabetes type 2, 1.19 (1.14-1.25) for hypertension, 1.26 (1.16-1.37) for ischaemic heart disease, 1.21 (1.03-1.42) for myocardial infarction, 1.32 (1.14-1.51) for atrial fibrillation or flutter and 1.23 (0.99-1.52) for heart failure. aHRs were 1.41 (1.26-1.57) and 1.46 (1.23-1.72) for ischaemic and haemorrhagic stroke, respectively. When contrasting VB-affected pregnancies with terminations, aHRs were up to 1.3-fold increased for diabetes and hypertension; however, when contrasting VB-affected pregnancies with miscarriages, estimates were below or close to the null value.

CONCLUSIONS

Women's risks of diabetes and cardiovascular outcomes later in life were increased following VB-affected vs VB-unaffected pregnancy or termination, but not following VB-affected pregnancy vs miscarriage.

Higher Habitual Dietary Intakes of Flavanols and Anthocyanins Differentially Associate with Lower Incidence of Ischemic Stroke Subtypes-A Follow-Up Analysis

BACKGROUND

We previously reported that habitual consumption of dietary flavanol oligomers + polymers and anthocyanins is associated with a lower risk of ischemic stroke. However, no studies have investigated their relationship with ischemic stroke subtypes.

OBJECTIVES

In this follow-up analysis, we aimed to examine the association of flavanol oligomers + polymers and anthocyanin intake with ischemic stroke subtypes, including the following: 1) large-artery atherosclerosis, 2) cardioembolism, 3) small-vessel occlusion, 4) other determined etiology, and 5) undetermined etiology.

METHODS

Participants (n = 55,094) from the Danish Diet, Cancer, and Health Study were followed up for <16 y for first-time ischemic stroke events, which were classified according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Intakes of flavanol oligomers + polymers and anthocyanins were calculated from food frequency questionnaires using the Phenol-Explorer database, and their relationships with ischemic stroke subtypes were investigated using restricted cubic splines within Cox proportional hazards models. After multivariable adjustment, higher habitual intakes (quintile 5 compared with quintile 1) of flavanol oligomers + polymers and anthocyanins were associated with a lower risk of specific ischemic stroke subtypes, including large-artery atherosclerosis [flavanol oligomers + polymers, hazard ratio {HR} (95% confidence interval {CI}): 0.64 (0.47, 0.87)], cardioembolism [anthocyanins, HR (95% CI): 0.45 (0.25, 0.82)], and small-vessel occlusion [flavanol oligomers + polymers, HR (95% CI): 0.65 (0.54, 0.80); anthocyanins, HR (95% CI): 0.79 (0.64, 0.97)], but not stroke of other determined or undetermined etiology.

CONCLUSIONS

Higher habitual intakes of flavanols and anthocyanins are differentially associated with a lower risk of ischemic stroke from atherosclerosis and/or cardioembolism but not with other subtypes.

Cardiovascular morbidity and all-cause mortality in patients with retinal vein occlusion: a Danish nationwide cohort study

BACKGROUND/AIMS

Associations between retinal vein occlusion (RVO) and subsequent cardiovascular disease (CVD) or mortality have not been evaluated in a recent cohort, after novel therapeutic options have increased referrals for treatment of the condition. We aimed to evaluate overall and subtype-stratified risk of CVD and all-cause mortality following RVO and assess any alterations after the introduction of angiostatic therapy in Denmark in 2011.

METHODS

This nationwide, registry-based cohort study from 1998 to 2018 evaluated 4 194 781 individuals. Hazard ratios (HRs) were reported for RVO as an overall measure and subclassified as branch and central RVO.

RESULTS

Patients with RVO (n=15 665) were median 71.8 years old at the time of exposure and 50.7% were women. RVO associated with incident CVD (adjusted HR 1.13, 95% CI 1.09 to 1.17) but not mortality (adjusted HR 1.00, 95% CI 0.97 to 1.03). Almost similar risks of CVD were found for patients with branch and central RVO (adjusted HRs 1.14, 95% CI 1.03 to 1.25, and 1.12, 95% CI 1.00 to 1.25, respectively), but only patients with central RVO exhibited increased mortality (adjusted HR 1.12, 95% CI 1.04 to 1.21). Risk of CVD, especially non-ischaemic, was higher for patients diagnosed after 2011 (adjusted HRs 1.24, 95% CI 1.15 to 1.33 vs 1.06, 95% CI 1.01 to 1.12).

CONCLUSION

In a cohort of the Danish population aged 40 years or more, patients with RVO had a 13% increased risk of incident CVD compared with unexposed individuals. Risk of CVD was increased after 2011, when intravitreal angiostatic treatment was introduced and referral practices altered.

Concomitant exposure to air pollution, green space, and noise and risk of stroke: a cohort study from Denmark

Background

Air pollution, road traffic noise, and green space are correlated factors, associated with risk of stroke. We investigated their independent relationship with stroke in multi-exposure analyses and estimated their cumulative stroke burden.

Methods

For all persons, ≥50 years of age and living in Denmark from 2005 to 2017, we established complete address histories and estimated running 5-year mean exposure to fine particles (PM_2.5), ultrafine particles, elemental carbon, nitrogen dioxide (NO₂), and road traffic noise at the most, and least exposed façade. For air pollutants, we estimated total, and non-traffic contributions. Green space around the residence was estimated from land use maps. Hazard ratios (HR) and 95% confidence limits (CL) were estimated with Cox proportional hazards models and used to calculate cumulative risk indices (CRI). We adjusted for the individual and sociodemographic covariates available in our dataset (which did not include information about individual life styles and medical conditions).

Findings

The cohort accumulated 18,344,976 years of follow-up and 94,256 cases of stroke. All exposures were associated with risk of stroke in single pollutant models. In multi-pollutant analyses, only PM_2.5 (HR: 1.058, 95% CI: 1.040-1.075) and noise at most exposed façade (HR: 1.033, 95% CI: 1.024-1.042) were independently associated with a higher risk of stroke. Both noise and air pollution contributed substantially to the CRI (1.103, 95% CI: 1.092-1.114) in the model with noise, green space, and total PM_2.5 concentrations.

Interpretation

Environmental exposure to air pollution and noise were both independently associated with risk of stroke.

Funding

Health Effects Institute (HEI) (Assistance Award No. R-82811201).

Triglycerides and risk of cardiovascular events in statin-treated patients with newly diagnosed type 2 diabetes: a Danish cohort study

BACKGROUND

Elevated triglyceride levels are a clinically useful marker of remnant cholesterol. It is unknown whether triglycerides are associated with residual cardiovascular risk in CVD-naïve patients with newly diagnosed type 2 diabetes mellitus (T2DM), who are already on statin therapy. We aimed to assess the association between triglyceride levels and risk of major cardiovascular events (MACE) in statin-treated patients with newly diagnosed T2DM managed in routine clinical care.

METHODS

This cohort study included newly diagnosed T2DM patients without a previous diagnosis of cardiovascular disease in Northern Denmark during 2005-2017. Individual triglyceride levels while on statin treatment were assessed within 1 year after T2DM diagnosis. The primary outcome was a composite of myocardial infarction, ischemic stroke, or cardiac death (MACE). Patients were followed from one year after T2DM diagnosis until 30 April 2021, MACE, emigration, or death. We used Cox regression to compute hazard ratios (HRs) controlling for confounding factors.

RESULTS

Among 27,080 statin-treated patients with T2DM (median age 63 years; 53% males), triglyceride levels were < 1.0 mmol/L in 17%, 1.0-1.9 mmol/L in 52%, 2.0-2.9 mmol/L in 20%, and ≥ 3.0 mmol/L in 11%. During follow-up, 1,957 incident MACE events occurred (11.0 per 1000 person-years). Compared with triglyceride levels < 1.0 mmol/L, confounder-adjusted HRs for incident MACE were 1.14 (95% CI 1.00-1.29) for levels between 1.0 and 1.9 mmol/L, 1.30 (95% CI 1.12-1.51) for levels between 2.0 and 2.9 mmol/L, and 1.44 (95% CI 1.20-1.73) for levels ≥ 3.0 mmol/L. This association was primarily driven by higher rates of myocardial infarction and cardiac death and attenuated only slightly after additional adjustment for LDL cholesterol. Spline analyses confirmed a linearly increasing risk of MACE with higher triglyceride levels. Stratified analyses showed that the associations between triglyceride levels and MACE were stronger among women.

CONCLUSIONS

In statin-treated patients with newly diagnosed T2DM, triglyceride levels are associated with MACE already from 1.0 mmol/L. This suggests that high triglyceride levels are a predictor of residual cardiovascular risk in early T2DM and could be used to guide allocation of additional lipid-lowering therapies for CVD prevention.

Visual symptoms in acute stroke - A systematic review of observational studies

OBJECTIVE

Atypical symptoms of stroke, such as non-specific visual symptoms, are a challenging aspect of acute stroke diagnostics. Among patients evaluated for stroke in the Emergency Department, 2-28% present with stroke chameleons, and 30-43% with stroke mimics. We aimed to identify the type of visual symptoms present in typical strokes, stroke mimics, and stroke chameleons.

PATIENTS AND METHODS

By use of Preferred Reporting Items for Systematic Reviews and Meta-Analysis we searched PubMed and Embase for studies with reports of acute visual symptoms in typical strokes vs mimics or chameleons (PROSPERO protocol, ID CRD42022364749). Risk of bias was assessed by The Critical Appraisal Skills Program.

RESULTS

Thirteen papers were included, comprising data from 9248 patients evaluated for stroke. Compared to mimics, visual symptoms in stroke presented more frequently as hemianopia (28.2% vs 4.8%, 7,4% vs 2.3%, 22% vs 0%), visual loss (11.6% vs 1.8%), visual field defect (11.6% vs 4%, 24% vs 2%, 19% vs 1.7%), eye movement disorder (19.4% vs 6.4%), eye deviation (9.6% vs 0.9%), gaze palsy (32.1% vs 8.6%), oculomotor disturbance (37% vs 0%), and visual inattention (17.5% vs 4%). Compared to strokes, mimics more often presented "non-systematized visual trouble" (10% vs 3%) and blurred vision (22% vs 5%), whereas "visual disturbance" was reported more often in stroke chameleons than in typical strokes (10% vs 3%).

CONCLUSION

Detailed reports of visual symptoms were lacking in most studies, however blurred vision and "non-systematized visual trouble" were more frequent in mimics, "visual disturbance" in stroke chameleons, and negative visual symptoms such as visual field defects in typical strokes. A more systematic and detailed approach to visual symptoms may facilitate acute stroke recognition in patients with visual symptoms.

Air pollution and stroke; effect modification by sociodemographic and environmental factors. A cohort study from Denmark

OBJECTIVES

Air pollution increases the risk of stroke, but the literature on identifying susceptible subgroups of populations is scarce and inconsistent. The aim of this study was to investigate if the association between air pollution and risk of stroke differed by sociodemographic factors, financial stress, comorbid conditions, and residential road traffic noise, population density and green space.

METHODS

We assessed long-term exposure to air pollution with ultrafine particles, PM_2.5, elemental carbon and NO₂ for a cohort of 1,971,246 Danes aged 50-85 years. During follow-up from 2005 to 2017, we identified 83,211 incident stroke cases. We used Cox proportional hazards model (relative risk) and Aalen additive hazards models (absolute risk) to estimate associations and confidence intervals (CI) between 5-year running means of air pollution at the residence and risk of stroke in population strata.

RESULTS

All four pollutants were associated with higher risk of stroke. The association between air pollution and stroke was strongest among individuals with comorbidities, with shorter education, lower income and being retired. The results also indicated stronger associations among individuals living in less populated areas, and with low noise levels and more green space around the residence. Estimates of absolute risk seemed better suited to detect such interactions than estimates of relative risk. For example for PM_2.5 the hazard ratio for stroke was 1.28 (95%CI: 1.22-1.34) and 1.26 (95%CI: 1.16-1.37) among those with mandatory and medium/long education respectively. The corresponding rate difference estimates per 100,000 person years were 568 (95%CI: 543-594) and 423(95%CI: 390-456) CONCLUSION: The associations between air pollution and risk of stroke was stronger among individuals of lower socioeconomic status or with pre-existing comorbid conditions. Absolute risk estimates were better suited to identify such effect modification.

Geographical Variation in the Use of Oral Anticoagulation and Clinical Outcomes among Patients with Atrial Fibrillation in Denmark, Sweden, and Finland

Background  Geographical mapping of variations in the treatment and outcomes of a disease is a valuable tool for identifying inequity. We examined international and intranational variations in initiating oral anticoagulation (OAC) therapy and clinical outcomes among patients with atrial fibrillation (AF) in Nordic countries. We also tracked real-world trends in initiating OAC and the clinical outcomes. Methods  We conducted a registry-based multinational cohort study of OAC-naive patients with an incident hospital diagnosis of AF in Denmark ( N  = 61,345), Sweden ( N  = 124,120), and Finland ( N  = 59,855) and a CHA ₂ DS ₂ -VASc score of ≥1 in men and ≥2 in women between 2012 and 2017. Initiation of OAC therapy was defined as dispensing at least one prescription between 90 days before and 90 days after the AF diagnosis. Clinical outcomes included ischemic stroke, intracerebral hemorrhage, intracranial bleeding, other major bleeding, and all-cause mortality. Results  The proportion of patients initiating OAC therapy ranged from 67.7% (95% CI: 67.5-68.0) in Sweden to 69.6% (95% CI: 69.2-70.0) in Finland, with intranational variation. The 1-year risk of stroke varied from 1.9% (95% CI: 1.8-2.0) in Sweden and Finland to 2.3% (95% CI: 2.2-2.4) in Denmark, with intranational variation. The initiation of OAC therapy increased with a preference for direct oral anticoagulants over warfarin. The risk of ischemic stroke decreased with no increase in intracranial and intracerebral bleeding. Conclusion  We documented inter- and intranational variation in initiating OAC therapy and clinical outcomes across Nordic countries. Adherence to structured care of patients with AF could reduce future variation.

Intake of marine and plant-derived n-3 fatty acids and development of atherosclerotic cardiovascular disease in the Danish Diet, Cancer and Health cohort

PURPOSE

The objective of this study was to investigate the association between intake of seafood and plant-derived n-3 polyunsaturated fatty acids (PUFA) and development of total atherosclerotic cardiovascular disease (ASCVD) and acute major ischemic events.

METHODS

A total of 53,909 men and women were enrolled between 1993 and 1997 into the Danish Diet, Cancer and Health cohort and followed through nationwide Danish registries for development of total ASCVD defined as a first registration of myocardial infarction, peripheral artery disease, or ischemic stroke due to large artery atherosclerosis or small-vessel occlusion. At recruitment, the intake of the major marine n-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and the plant-derived n-3 PUFA, alpha-linolenic acid (ALA), was assessed using a validated food frequency questionnaire. Statistical analyses were conducted using sex-stratified multivariable Cox proportional hazard regression models.

RESULTS

During a median of 13.5 years of follow-up, 3958 participants developed ASCVD including 3270 patients with an acute major ischemic event. In multivariable analyses including adjustment for established risk factors, we found no associations for intake of ALA, but indications of inverse associations between intake of EPA, DHA and EPA + DHA and the rate of total ASCVD and acute major ischemic events.

CONCLUSIONS

A high intake of marine n-3 PUFA was associated with a lower risk of total ASCVD and acute major ischemic events, whereas no association could be demonstrated for the plant-derived ALA.

Positive Predictive Value of Non-Traumatic Bleeding Diagnoses in the Danish National Patient Register

Purpose

The majority of bleeding diagnoses in the Danish National Patient Registry have not been validated despite extensive use in epidemiological research. Therefore, we examined the positive predictive value (PPV) of non-traumatic bleeding diagnoses in the Danish National Patient Registry.

Study Design

Population-based validation study.

Patients and Methods

Based on a manual review of electronic medical records, we estimated the PPV of diagnostic coding (International Classification of Diseases, Tenth Revision (ICD-10)) for non-traumatic bleeding for all patients ≥65 years of age with any hospital contact in the North Denmark Region during March-December 2019 as registered in the Danish National Patient Registry. We calculated PPVs and associated 95% confidence intervals (CI) for non-traumatic bleeding diagnoses overall and stratified according to primary or secondary diagnosis, and according to major anatomical sites.

Results

A total of 907 electronic medical records were available for review. The population mean age was 79.33 years (standard deviation (SD)=7.73) and 57.6% were males. Primary bleeding diagnoses accounted for 766 of the records and 141 were secondary bleeding diagnoses. The overall PPV for bleeding diagnoses was 94.0% (95% CI: 92.3-95.4). The PPV was 98.7% (95% CI: 97.6-99.3) for the primary diagnoses and 68.8% (95% CI: 60.7-75.9) for the secondary diagnoses. When stratified according to subgroups of major anatomical sites, the PPVs ranged between 94.1% and 100% for the primary diagnoses, and between 53.8% and 100% for secondary diagnoses.

Conclusion

The overall validity of non-traumatic bleeding diagnoses in the Danish National Patient Registry is high and considered acceptable for epidemiological research. However, PPVs were substantially higher for primary than for secondary diagnosis.

Risk and Subtypes of Stroke Following New-Onset Postoperative Atrial Fibrillation in Coronary Bypass Surgery: A Population-Based Cohort Study

Background New-onset postoperative atrial fibrillation (POAF) develops in approximately one-third of patients undergoing cardiac surgery and is associated with a higher incidence of ischemic stroke and increased mortality. However, it remains unknown to what extent ischemic stroke events in patients with POAF are cardioembolic and whether anticoagulant therapy is indicated. We investigated the long-term risk and pathogenesis of postoperative stroke in patients undergoing coronary artery bypass grafting experiencing POAF. Methods and Results This was a register-based cohort study. Data from the WDHR (Western Denmark Heart Registry) were linked with the DNPR (Danish National Patient Register), the Danish National Prescription Register, and the Cause of Death Register. All stroke diagnoses were verified, and ischemic stroke cases were subclassified according to pathogenesis. Furthermore, investigations of all-cause mortality and the use of anticoagulation medicine for the individual patient were performed. A total of 7813 patients without a preoperative history of atrial fibrillation underwent isolated coronary artery bypass grafting between January 1, 2010, and December 31, 2018, in Western Denmark. POAF was registered in 2049 (26.2%) patients, and a postoperative ischemic stroke was registered in 195 (2.5%) of the patients. After adjustment, there was no difference in the risk of ischemic stroke (hazard ratio [HR], 1.08 [95% CI, 0.74-1.56]) or all-cause mortality (HR, 1.09 [95% CI, 0.98-1.23]) between patients who developed POAF and non-POAF patients. Although not statistically significant, patients with POAF had a higher incidence rate (IR; per 1000 patient-years) of cardioembolic stroke (IR, 1 [95% CI, 0.6-1.6] versus IR, 0.5 [95% CI, 0.3-0.8]), whereas non-POAF patients had a higher incidence rate of large-artery occlusion stroke (IR, 1.1 [95% CI, 0.8-1.5] versus IR, 0.7 [95% CI, 0.4-1.4]). Early initiation of anticoagulation medicine was not associated with a lower risk of ischemic stroke. However, patients with POAF were more likely to die of cardiovascular causes than non-POAF patients (P<0.001). Conclusions We found no difference in the adjusted risk of postoperative stroke or all-cause mortality in POAF versus non-POAF patients. Patients with POAF after coronary artery bypass grafting presented with a higher, although not significant, proportion of ischemic strokes of the cardioembolic type.

The Khorana score and venous and arterial thrombosis in patients with cancer treated with immune checkpoint inhibitors: A Danish cohort study

BACKGROUND

Thrombosis is common among patients with cancer. Primary thromboprophylaxis guided by the Khorana score is endorsed by guidelines but recommendations rely mainly on data from patients treated with chemotherapy.

OBJECTIVES

To explore if the Khorana score could risk stratify patients with cancer treated with immune checkpoint inhibitors according to risk of venous and arterial thrombosis.

PATIENTS/METHODS

The study population and Khorana score were defined using administrative Danish health registries. The primary outcome was 6-month risk of venous thromboembolism after initiation of checkpoint inhibitor treatment. Secondary outcomes were arterial thrombosis and any thromboembolic event. Death was considered a competing risk event.

RESULTS

Among 3946 patients with cancer initiating checkpoint inhibitor treatment without other indications for anticoagulation, the overall 6-month incidence of venous thromboembolism was 2.6% (95% confidence interval [CI]: 2.1-3.1). Risks were 2.1% (95% CI: 1.5-3.0), 2.6% (95% CI: 2.0-3.4), and 3.7% (95% CI: 2.1-5.9) in low (score 0), intermediate (score 1-2), and high risk (score ≥3) Khorana categories, respectively. Among patients eligible for primary thromboprophylaxis according to guidelines (Khorana score ≥2), risk of venous thromboembolism was 4.1% (95% CI: 3.1-5.4). Higher Khorana risk category was also associated with higher 6-month risk of both arterial thrombosis and any thromboembolic events.

CONCLUSIONS

The Khorana score was able to risk stratify patients with cancer treated with immune checkpoint inhibitors according to 6-month risk of thromboembolic events. Risks of venous thromboembolism were lower than in randomized thromboprophylaxis trials, thus questioning the absolute benefit of routine primary thromboprophylaxis in an unselected population of patients treated with immune checkpoint inhibitors.

Risk factors for suicide one year after discharge from hospitalization for physical illness in Denmark

While suicide risk following psychiatric hospitalization has been studied extensively, risk following hospitalization for physical illness is less well understood. We used random forests to examine risk factors for suicide in the year following physical illness hospitalization in Denmark. In this case-cohort study, suicide cases were all individuals who died by suicide within one year of a hospitalization for a physical illness (n = 4563) and the comparison subcohort was a 5% random sample of individuals living in Denmark on January 1, 1995 who had a hospitalization for a physical illness between January 1, 1995 and December 31, 2015 (n = 177,664). We used random forests to examine identify the most important predictors of suicide stratified by sex. For women, the top 10 most important variables for random forest prediction were all related to psychiatric diagnoses. For men, many physical health conditions also appeared important to suicide prediction. Among the top 10 variables in the variable importance plot for men were influenza, injuries to the head, nervous system surgeries, and cerebrovascular diseases. Suicide prediction after a physical illness hospitalization requires comprehensive consideration of different and multiple factors for each sex.

Risk of stroke or systemic embolism in patients with degenerative mitral stenosis with or without atrial fibrillation: A cohort study

Background

Atrial fibrillation (AF) is associated with an increased risk of stroke and the combination of AF and mitral stenosis (MS) is associated with a higher risk. In developed nations, degenerative mitral stenosis (DMS) constitutes a sizeable proportion of patients with MS. Current international guidelines do not offer recommendations regarding anticoagulation in these patients. The objective of this study was to describe the incidence of stroke or systemic embolism in patients with DMS with or without prevalent AF.

Methods

A cohort study of DMS patients from 1997 to 2018, using data from the Danish health registries. The cohort was stratified based on AF prevalence and prior ischemic stroke. The primary outcome was a diagnosis of ischemic stroke or systemic embolism after 1 year of follow-up from time of DMS diagnosis.

Results

The study included 1162 patients with DMS, of which 421 had prevalent AF. The incidence rate of stroke or systemic embolism after 1 year of follow-up was highest in the DMS without AF group (7.58 vs. 6.63 per 100 person-years). In both groups, DMS without AF and DMS with AF, the incidence rate was highest in patients with prior thromboembolic events (29.61 vs. 5.15 and 19.53 vs. 5.15, respectively).

Conclusions

The incidence rate of stroke or systemic embolism was highest in DMS patients without AF. Current Danish guidelines recommend DMS patients should be treated with anticoagulation only with concurrent AF, yet our results call for additional research to establish if DMS patients without AF could benefit from stroke prevention therapy.

Diagnostic accuracy of major stroke types in Chinese adults: A clinical adjudication study involving 40,000 stroke cases

Background

Methods

Findings

Interpretation

Funding

Death of a Child and the Risk of Stroke: A Binational Cohort Study From Denmark and Sweden

BACKGROUND AND OBJECTIVES

The death of a child is an extreme life event with potentially long-term health consequences. Accumulating evidence suggests that parents who lost a child have increased risks of cardiovascular diseases, including ischemic heart disease and atrial fibrillation. Whether bereaved parents have an increased risk of stroke is unclear and was investigated in this study.

METHODS

We conducted a population-based cohort study including parents who had a child born during 1973-2016 or 1973-2014 and recorded in the Danish and the Swedish Medical Birth Registers, respectively. We obtained information on child's death, parent's stroke and socioeconomic and health-related characteristics through linkage between several population-based registers. We used Poisson regression to examine the association between the death of a child and the risk of stroke.

RESULTS

Of the 6,711,955 study participants, 128,744 (1.9%) experienced the death of a child and 141,840 (2.1%) had a stroke during the follow-up. Bereaved parents had an increased risk of stroke; the corresponding incidence rate ratio (95% confidence intervals) was 1.23 (1.19-1.27). The association was present for all analyzed categories of causes of child death (cardiovascular, other natural and unnatural death), did not differ substantially according to the age of the deceased child, but was stronger if the parent had no or ≥3 than 1-2 live children at the time of the loss. The association was similar for ischemic and hemorrhagic stroke. The risk for hemorrhagic stroke was highest immediately after the death of a child and decreased afterwards. In contrast, there was no clear pattern over time in case of ischemic stroke.

DISCUSSION

The death of a child was associated with a modestly increased risk of stroke. The finding that an association was observed in case of unnatural deaths is suggestive of the explanation that bereavement-related stress may contribute to the development of stroke. Though the death of a child can often not be avoided, an understanding of its health-related consequences may highlight the need for improved support and attention from family members and healthcare professionals.

Adherence to the EAT-Lancet Diet and Risk of Stroke and Stroke Subtypes: A Cohort Study

BACKGROUND AND PURPOSE

We investigated the association between adherence to the EAT-Lancet diet, a sustainable and mostly plant-based diet, and risk of stroke and subtypes of stroke in a Danish population. For comparison, we also investigated the Alternate Healthy Eating Index-2010 (AHEI).

METHODS

We used the Danish Diet, Cancer and Health cohort (n=55 016) including adults aged 50 to 64 years at baseline (1993-1997). A food frequency questionnaire was used to assess dietary intake and group participants according to adherence to the diets. Stroke cases were identified using a national registry and subsequently validated by review of medical records (n=2253). Cox proportional hazards models were used to estimate hazard ratios and 95% CIs for associations with the EAT-Lancet diet or the AHEI and risk of stroke and stroke subtypes.

RESULTS

Adherence to the EAT-Lancet diet was associated with a lower risk of stroke, although not statistically significant (highest versus lowest adherence: hazard ratio, 0.91 [95% CI, 0.76-1.09]). A lower risk was observed for AHEI (0.75 [95% CI, 0.64-0.87]). For stroke subtypes, we found that adherence to the EAT-Lancet diet was associated with a lower risk of subarachnoid hemorrhage (0.30 [95% CI, 0.12-0.73]), and the AHEI was associated with a lower risk of ischemic stroke (0.76 [95% CI, 0.64-0.90]) and intracerebral hemorrhage (0.58 [95% CI, 0.36-0.93]).

CONCLUSIONS

Adherence to the EAT-Lancet diet in midlife was associated with a lower risk of subarachnoid stroke, and the AHEI was associated with a lower risk of total stroke, mainly ischemic stroke and intracerebral hemorrhage.

Predicting Sex-Specific Nonfatal Suicide Attempt Risk Using Machine Learning and Data From Danish National Registries

Suicide attempts are a leading cause of injury globally. Accurate prediction of suicide attempts might offer opportunities for prevention. This case-cohort study used machine learning to examine sex-specific risk profiles for suicide attempts in Danish nationwide registry data. Cases were all persons who made a nonfatal suicide attempt between 1995 and 2015 (n = 22,974); the subcohort was a 5% random sample of the population at risk on January 1, 1995 (n = 265,183). We developed sex-stratified classification trees and random forests using 1,458 predictors, including demographic factors, family histories, psychiatric and physical health diagnoses, surgery, and prescribed medications. We found that substance use disorders/treatment, prescribed psychiatric medications, previous poisoning diagnoses, and stress disorders were important factors for predicting suicide attempts among men and women. Individuals in the top 5% of predicted risk accounted for 44.7% of all suicide attempts among men and 43.2% of all attempts among women. Our findings illuminate novel risk factors and interactions that are most predictive of nonfatal suicide attempts, while consistency between our findings and previous work in this area adds to the call to move machine learning suicide research toward the examination of high-risk subpopulations.

Risk of major cardiovascular events according to educational level before and after the initial COVID-19 public lockdown: a nationwide study

BACKGROUND

During the COVID-19 pandemic, decreasing rates of hospitalisations for cardiovascular disease raised concerns for undertreatment, particularly for vulnerable groups. We investigated how the initial COVID-19 public lockdown, impacted the risk of being hospitalised with a major cardiovascular event (MCE: myocardial infarction/stroke/heart failure) according to educational level.

METHODS

We grouped all Danish residents according to educational attainment level (low, medium, high) and age (40-59, 60-69, ≥70 years). In each group, we calculated the age-standardised and sex standardised risk of MCE hospitalisation in the initial COVID-19 lockdown-period (13 March 2020-3 May 2020) and in the corresponding calendar period in 2019. We calculated age-standardised and sex-standardised risks to investigate whether the COVID-19 lockdown had a differential effect on MCE incidence according to educational level.

RESULTS

In the period in 2019, 2700 Danish residents were hospitalised with MCE, compared with only 2290 during the lockdown. During lockdown, the risk of hospitalisation for MCE decreased among residents aged ≥70 with low education (risk difference (RD) -46.2 (-73.2; -19.2) per 100,000) or medium education (RD -23.2 (-50.8; 4.3) per 100 000), but not among residents with high education (RD 5.1 (-32.3; 42.5), per 100 000). The risk of hospitalisation for MCE did not decrease significantly for the younger age groups.

CONCLUSIONS

The COVID-19 lockdown is associated with a reduced incidence for MCE, especially among low educated, elderly residents. This raises concern for undertreatment that without clinical awareness and action may widen the educational gap in cardiovascular morbidity and mortality.

Urinary cadmium and stroke - a case-cohort study in Danish never-smokers

BACKGROUND

and Purpose: Cadmium has been associated with risk of cardiovascular events, including stroke. Human cadmium exposure occurs primarily through diet and tobacco smoke. Recent cohort studies have found an association with stroke, but residual confounding from smoking, could not be ruled out. We therefore conducted a case-cohort study to evaluate whether cadmium is associated with stroke in never-smokers.

METHODS

The Danish Diet Cancer and Health cohort consists of Danes 50-64 years old, recruited in 1993-1997. From never-smoking cohort members without previous cancer or stroke we sampled a sub-cohort of 1200 persons. We also identified all (n = 534) cases in the cohort with a validated stroke diagnosis between baseline and 2009. We quantified cadmium and creatinine concentrations from baseline urine samples and used cadmium per creatinine as our main exposure metric. We used Cox proportional hazards models to estimate hazard ratios (HRs) with age as time scale and adjusting for BMI, education and urinary cotinine with and without stratification by sex.

RESULTS

The median urinary cadmium concentration was 0.21 μg cadmium/g creatinine in cases and 0.19 μg/g in the sub-cohort. The majority (83%) of stroke cases were diagnosed with ischemic stroke. The HR for stroke in the highest quartile of exposure (median 0.44 μg/g creatinine) was 1.11 (95% CI: 0.79-1.54) compared with the lowest quartile (median 0.10 μg/g creatinine). The HR per inter quartile range (IQR, 0.19 μg/g creatinine) was 1.02 (95% CI: 0.92-1.12). Among men, the HR per IQR higher levels of cadmium (0.16 μg/g creatinine) was 1.18 (95% CI: 0.92-1.52), and 1.00 (95% CI: 0.89-1.12) among women. Adjusting for creatinine or using osmolality instead of creatinine standardization generally attenuated observed relationships.

CONCLUSIONS

Our results do not support that low levels of cadmium exposure among never-smokers are strongly associated with risk of stroke, although results varied somewhat by sex and method of accounting for urinary dilution.

Joint mapping of cardiovascular diseases: comparing the geographic patterns in incident acute myocardial infarction, stroke and atrial fibrillation, a Danish register-based cohort study 2014-15

BACKGROUND

Disease mapping aims at identifying geographic patterns in disease. This may provide a better understanding of disease aetiology and risk factors as well as enable targeted prevention and allocation of resources. Joint mapping of multiple diseases may lead to improved insights since e.g. similarities and differences between geographic patterns may reflect shared and disease-specific determinants of disease. The objective of this study was to compare the geographic patterns in incident acute myocardial infarction (AMI), stroke and atrial fibrillation (AF) using the unique, population-based Danish register data.

METHODS

Incident AMI, stroke and AF was modelled by a multivariate Poisson model including a disease-specific random effect of municipality modelled by a multivariate conditionally autoregressive (MCAR) structure. Analyses were adjusted for age, sex and income.

RESULTS

The study included 3.5 million adults contributing 6.8 million person-years. In total, 18,349 incident cases of AMI, 28,006 incident cases of stroke, and 39,040 incident cases of AF occurred. Estimated municipality-specific standardized incidence rates ranged from 0.76 to 1.35 for AMI, from 0.79 to 1.38 for stroke, and from 0.85 to 1.24 for AF. In all diseases, geographic variation with clusters of high or low risk of disease after adjustment was seen. The geographic patterns displayed overall similarities between the diseases, with stroke and AF having the strongest resemblances. The most notable difference was observed in Copenhagen (high risk of stroke and AF, low risk of AMI). AF showed the least geographic variation.

CONCLUSION

Using multiple-disease mapping, this study adds to the results of previous studies by enabling joint evaluation and comparison of the geographic patterns in AMI, stroke and AF. The simultaneous mapping of diseases displayed similarities and differences in occurrence that are non-assessable in traditional single-disease mapping studies. In addition to reflecting the fact that AF is a strong risk factor for stroke, the results suggested that AMI, stroke and AF share some, but not all environmental risk factors after accounting for age, sex and income (indicator of lifestyle and health behaviour).

Vitamin K Intake and Atherosclerotic Cardiovascular Disease in the Danish Diet Cancer and Health Study

Background

Dietary vitamin K (K₁ and K₂) may reduce atherosclerotic cardiovascular disease (ASCVD) risk via several mechanisms. However, studies linking vitamin K intake with incident ASCVD are limited. We aimed to determine the relationship between dietary vitamin K intake and ASCVD hospitalizations.

Methods and Results

In this prospective cohort study, participants from the Danish Diet, Cancer, and Health Study, with no prior ASCVD, completed a food‐frequency questionnaire at baseline and were followed up for hospital admissions of ASCVD; ischemic heart disease, ischemic stroke, or peripheral artery disease. Intakes of vitamin K₁ and vitamin K₂ were estimated from the food‐frequency questionnaire, and their relationship with ASCVD hospitalizations was determined using Cox proportional hazards models. Among 53 372 Danish citizens with a median (interquartile range) age of 56 (52–60) years, 8726 individuals were hospitalized for any ASCVD during 21 (17–22) years of follow‐up. Compared with participants with the lowest vitamin K₁ intakes, participants with the highest intakes had a 21% lower risk of an ASCVD‐related hospitalization (hazard ratio, 0.79; 95% CI: 0.74–0.84), after multivariable adjustments for relevant demographic covariates. Likewise for vitamin K₂, the risk of an ASCVD‐related hospitalization for participants with the highest intakes was 14% lower than participants with the lowest vitamin K₂ intake (hazard ratio, 0.86; 95% CI, 0.81–0.91).

Conclusions

Risk of ASCVD was inversely associated with diets high in vitamin K₁ or K₂. The similar inverse associations with both vitamin K₁ and K₂, despite very different dietary sources, highlight the potential importance of vitamin K for ASCVD prevention.

Using machine learning to predict suicide in the 30 days after discharge from psychiatric hospital in Denmark

BACKGROUND

Suicide risk is high in the 30 days after discharge from psychiatric hospital, but knowledge of the profiles of high-risk patients remains limited.

AIMS

To examine sex-specific risk profiles for suicide in the 30 days after discharge from psychiatric hospital, using machine learning and Danish registry data.

METHOD

We conducted a case-cohort study capturing all suicide cases occurring in the 30 days after psychiatric hospital discharge in Denmark from 1 January 1995 to 31 December 2015 (n = 1205). The comparison subcohort was a 5% random sample of all persons born or residing in Denmark on 1 January 1995, and who had a first psychiatric hospital admission between 1995 and 2015 (n = 24 559). Predictors included diagnoses, surgeries, prescribed medications and demographic information. The outcome was suicide death recorded in the Danish Cause of Death Registry.

RESULTS

For men, prescriptions for anxiolytics and drugs used in addictive disorders interacted with other characteristics in the risk profiles (e.g. alcohol-related disorders, hypnotics and sedatives) that led to higher risk of postdischarge suicide. In women, there was interaction between recurrent major depression and other characteristics (e.g. poisoning, low income) that led to increased risk of suicide. Random forests identified important suicide predictors: alcohol-related disorders and nicotine dependence in men and poisoning in women.

CONCLUSIONS

Our findings suggest that accurate prediction of suicide during the high-risk period immediately after psychiatric hospital discharge may require a complex evaluation of multiple factors for men and women.

The familial and genetic contribution to the association between depression and cardiovascular disease: a twin cohort study

Depression and cardiovascular disease (ischemic heart disease and stroke) are associated in a bidirectional manner. Their relatively high heritability has led to the hypothesis that this co-occurrence is related to shared familial and genetic factors; this study aims to test this hypothesis. We included 23,498 monozygotic and 39,540 same-sex dizygotic twins from the Danish Twin Registry followed from January 1977 until December 2011 in nationwide Danish registries. We used survival analyses accounting for censoring and competing risk of death to estimate cumulative incidence, casewise concordance, relative recurrence risk, and heritability of the co-occurrence of depression and cardiovascular disease by age using monozygotic and same-sex dizygotic twin pairs. The casewise concordance of ischemic heart disease or stroke in twins whose co-twin was diagnosed with depression was at all ages similar for the monozygotic and dizygotic twin pairs and to the cumulative incidence of ischemic heart disease or stroke, respectively, in the entire twin population. A similar pattern was seen in analyses of depression risk given the co-twin being diagnosed with ischemic heart disease or stroke. Relative recurrence risk and heritability estimates were also of modest size and with confidence intervals including unity. Results were similar after stratification by gender as well as when redefining depression to include the use of antidepressant medication from 1995. Our findings do not support that co-occurrence between depression and cardiovascular disease is explainable by shared genetic factors, nor did we find strong evidence of a familial effect.

Paediatric ischaemic stroke is a valid diagnosis in the Swedish National Patient Register

AIM

The Swedish National Patient Register offers unique opportunities for epidemiological research of paediatric ischaemic stroke. We aimed to validate the diagnosis of paediatric ischaemic stroke in the National Patient Register to ensure the quality of future research.

METHODS

The PedStroke cohort consists of 1606 individuals aged <18 years with a diagnosis of paediatric ischaemic stroke (ICD-10: I63, I64; ICD-8 and 9: 433, 434, 436) in Swedish national health registers between 1969 and 2016. We selected 292 cases for validation by reviewing medical charts.

RESULTS

In all, 277 of the 292 medical charts were received, of which 273 had enough information to qualify for review. The diagnosis was correct in 242/273 cases, yielding a positive predictive value (PPV) of 89% (95% confidence interval (CI): 0.85-0.92) for paediatric ischaemic stroke in the National Patient Register. After validation, seven cases of 222 with childhood stroke were re-categorised to perinatal stroke, resulting in a total of 56 perinatal stroke cases. In the Medical Birth Register, 38 stroke cases were identified of which 37 had correct diagnosis, generating a PPV of 97% (95% CI: 0.92-1.0). Incorrect diagnoses decreased over time and the number of diagnoses confirmed by radiology increased correspondingly.

CONCLUSION

The National Patient Register is reliable for epidemiological research of paediatric ischaemic stroke because of its high PPV for this diagnosis.

Habitual flavonoid intake and ischemic stroke incidence in the Danish Diet, Cancer, and Health Cohort

BACKGROUND

Flavonoid-rich foods have antiinflammatory, antiatherogenic, and antithrombotic properties that may contribute to a lower risk of ischemic stroke.

OBJECTIVES

We aimed to investigate the relationship between habitual flavonoid consumption and incidence of ischemic stroke in participants from the Danish Diet, Cancer and Health Study.

DESIGN

In this prospective cohort study, 55,169 Danish residents without a prior ischemic stroke [median (IQR) age at enrolment of 56 y (52-60)], were followed for 21 y (20-22). We used Phenol-Explorer to estimate flavonoid intake from food frequency questionnaires obtained at study entry. Incident cases of ischemic stroke were identified from Danish nationwide registries and restricted cubic splines in Cox proportional hazards models were used to investigate relationships with flavonoid intake.

RESULTS

During follow-up, 4237 individuals experienced an ischemic stroke. Compared with participants in Q1 and after multivariable adjustment for demographics and lifestyle factors, those in Q5-for intake of total flavonoids, flavonols, and flavanol oligo + polymers-had a 12% [HR (95% CI): 0.88 (0.81, 0.96)], 10% [0.90 (0.82, 0.98)], and 18% [0.82 (0.75, 0.89)] lower risk of ischemic stroke incidence, respectively. Multivariable (demographic and lifestyle) adjusted associations for anthocyanins and flavones with risk of ischemic stroke were not linear, with moderate but not higher intakes associated with lower risk [anthocyanins Q3 vs. Q1 HR (95% CI): 0.85 (0.79, 0.93); flavones: 0.90 (0.84, 0.97)]. Following additional adjustment for dietary confounders, similar point estimates were observed; however, significance was only retained for anthocyanins and flavanol oligo + polymers [anthocyanins Q3 vs. Q1 HR (95% CI): 0.86 (0.79, 0.94); flavanol oligo + polymers Q5 vs. Q1 0.86 (0.78, 0.94)].

CONCLUSIONS

These findings suggest that moderate habitual consumption of healthy flavonoid-rich foods is associated with a lower risk of ischemic stroke and further investigation is therefore warranted.

Is the risk of cardiovascular disease increased in living kidney donors? A Danish population-based cohort study

Reduced renal function is associated with cardiovascular disease (CVD); however, how living donor nephrectomy affects the risk of CVD remains controversial. We conducted a nationwide cohort study including living kidney donors in Denmark from 1996 to 2018 to assess the risk of hypertension, atrial fibrillation/flutter (AF), major adverse cardiovascular events (MACE; composite of myocardial infarction, ischemic stroke, and death) and death after living kidney donation. As comparisons we identified: a cohort of healthy individuals from the general population and an external blood donor cohort. We followed kidney donors (1,103 when compared with the general population cohort; 1,007 when compared with blood donors) for a median of 8 years. Kidney donors had an increased risk of initiating treatment for hypertension when compared with blood donors (standardized incidence ratio [SIR], 1.40; 95% confidence interval [CI], 1.17-1.66) but they did not have increased risk of MACE neither when compared with the general population cohort (hazard ratio, 0.68; 95% CI, 0.52-0.89) nor with blood donors (SIR, 1.17; 95% CI, 0.88-1.55). Neither did they have increased risks of AF and death. Thus, living kidney donation may be associated with increased risk of hypertension; however, we did not identify increased risks of CVD or death.

Vegetable nitrate intake, blood pressure and incident cardiovascular disease: Danish Diet, Cancer, and Health Study

Whether the vascular effects of inorganic nitrate, observed in clinical trials, translate to a reduction in cardiovascular disease (CVD) with habitual dietary nitrate intake in prospective studies warrants investigation. We aimed to determine if vegetable nitrate, the major dietary nitrate source, is associated with lower blood pressure (BP) and lower risk of incident CVD. Among 53,150 participants of the Danish Diet, Cancer, and Health Study, without CVD at baseline, vegetable nitrate intake was assessed using a comprehensive vegetable nitrate database. Hazard ratios (HRs) were calculated using restricted cubic splines based on multivariable-adjusted Cox proportional hazards models. During 23 years of follow-up, 14,088 cases of incident CVD were recorded. Participants in the highest vegetable nitrate intake quintile (median, 141 mg/day) had 2.58 mmHg lower baseline systolic BP (95%CI − 3.12, − 2.05) and 1.38 mmHg lower diastolic BP (95%CI − 1.66, − 1.10), compared with participants in the lowest quintile. Vegetable nitrate intake was inversely associated with CVD plateauing at moderate intakes (~ 60 mg/day); this appeared to be mediated by systolic BP (21.9%). Compared to participants in the lowest intake quintile (median, 23 mg/day), a moderate vegetable nitrate intake (median, 59 mg/day) was associated with 15% lower risk of CVD [HR (95% CI) 0.85 (0.82, 0.89)]. Moderate vegetable nitrate intake was associated with 12%, 15%, 17% and 26% lower risk of ischemic heart disease, heart failure, ischemic stroke and peripheral artery disease hospitalizations respectively. Consumption of at least ~ 60 mg/day of vegetable nitrate (~ 1 cup of green leafy vegetables) may mitigate risk of CVD.

Should We Reintroduce Previous Venous Thromboembolism Into Decision-Making for Anticoagulation in Atrial Fibrillation?

BACKGROUND

We aimed to investigate whether history of venous thromboembolism should be considered a prognostic factor for future thromboembolic events in patients with atrial fibrillation.

METHODS

This was a nationwide cohort study of patients with incident atrial fibrillation from 2000-2017, defined and characterized using Danish health registries. Cox regression analyses were used to calculate hazard ratios and 95% confidence intervals for the outcomes ischemic stroke or systemic embolism, and ischemic stroke, systemic embolism, or venous thromboembolism, according to history of venous thromboembolism. Analyses were adjusted for components of the CHA₂DS₂-VASc score and time-varying use of oral anticoagulation.

RESULTS

The study included 246,313 patients with incident atrial fibrillation, of which 6,516 (2.6%) had previous venous thromboembolism. Patients with previous venous thromboembolism carried an overall similar adjusted risk of ischemic stroke or systemic embolism compared with patients without previous venous thromboembolism (reference; hazard ratio 0.99; 95% confidence interval, 0.90-1.09). When analyzing a composite thromboembolic outcome of ischemic stroke, systemic embolism, or venous thromboembolism, patients with previous venous thromboembolism were at high-risk (hazard ratio 1.76; 95% confidence interval, 1.64-1.90). Similar conclusions were drawn when stratifying by venous thromboembolism subtype, and when restricting to patients with low CHA₂DS₂-VASc scores or the non-anticoagulated subset of the study population.

CONCLUSION

Patients with atrial fibrillation and previous venous thromboembolism carried similar risk of ischemic stroke or systemic embolism compared with patients with atrial fibrillation without previous venous thromboembolism. Nonetheless, patients with previous venous thromboembolism remain a high-risk population due to an excess risk of future venous thromboembolism. Patients and physicians should keep this excess thromboembolic risk in mind when weighing the expected risks and benefits of oral anticoagulation in patients with atrial fibrillation.

Thromboembolic Risk in Nonanticoagulated Patients With Atrial Fibrillation and Valvular Heart Disease

OBJECTIVES

This study sought to describe the risk of thromboembolism in nonanticoagulated atrial fibrillation patients with Evaluated Heartvalves, Rheumatic or Artificial (EHRA) Type 2 valvular heart disease (VHD) <65 or 65 to 74 years of age and with 0 or 1 non-sex comorbidity of the CHA₂DS₂-VASc score.

BACKGROUND

A minor, but important, proportion of patients with atrial fibrillation and VHD beyond moderate-to-severe mitral stenosis and/or a mechanical prosthetic valve, so-called EHRA Type 2 VHD, have 0 or 1 coexisting non-sex comorbidities of the CHA₂DS₂-VASc score, and are therefore not strongly recommended oral anticoagulant therapy according to guidelines. Whether these patients are truly low risk of thromboembolism has not been investigated.

METHODS

This was a cohort study of 55,613 patients identified in nationwide Danish registries from 2000 to 2018, of which 1,907 patients had EHRA Type 2 VHD. Risk of thromboembolism after 1 and 5 years of follow-up were calculated.

RESULTS

At 1 year after atrial fibrillation diagnosis, patients with EHRA Type 2 VHD had a risk of thromboembolism between 1.2% and 1.5%, according to age group (<65 or 65 to 74 years of age), and number of non-sex comorbidities of the CHA₂DS₂-VASc score (0 or 1). Interestingly, in patients with EHRA Type 2 VHD <65 years of age with 0 or 1 comorbidity, the risk was 1.5% (95% confidence interval: 0.7% to 2.8%) and 1.5% (95% confidence interval: 0.6% to 3.4%) at 1 year after the atrial fibrillation diagnosis.

CONCLUSIONS

These observations suggest that in atrial fibrillation patients with EHRA Type 2 VHD, who are not currently recommended oral anticoagulant therapy according to guidelines, the risk of thromboembolism may exceed the level above which oral anticoagulation is considered beneficial.

The Validity of Intracerebral Hemorrhage Diagnoses in the Danish Patient Registry and the Danish Stroke Registry

Purpose

To establish the validity of intracerebral hemorrhage (ICH) diagnoses in the Danish Stroke Registry (DSR) and the Danish National Patient Registry (DNPR).

Patients and Methods

Based on discharge summaries and brain imaging reports, we estimated the positive predictive value (PPV) of a first-ever diagnosis code for ICH (ICD-10, code I61) for all patients in the Region of Southern Denmark (1.2 million) during 2009-2017 according to either DNPR or DSR. We estimated PPVs for any non-traumatic ICH (a-ICH) and spontaneous ICH (s-ICH) alone (ie, without underlying structural cause). We also calculated the sensitivity of these diagnoses in each of the registers. Finally, we classified the location of verified s-ICH.

Results

A total of 3,956 patients with ICH diagnosis codes were studied (DSR only: 87; DNPR only: 1,513; both registries: 2,356). In the DSR, the PPVs were 86.5% (95% CI=85.1-87.8) for a-ICH and 81.8% (95% CI=80.2-83.3) for s-ICH. The PPVs in DNPR (discharge code, primary diagnostic position) were 76.2% (95% CI=74.7-77.6) for a-ICH and 70.2% (95% CI=68.6-71.8) for s-ICH. Sensitivity for a-ICH and s-ICH was 76.4% (95% CI=74.8-78.0) and 78.7% (95% CI=77.1-80.2) in DSR, and 87.3% (95% CI=86.0-88.5) and 87.7% (95% CI=86.3-88.9) in DNPR. The location of verified s-ICH was lobar (39%), deep (33.6%), infratentorial (13.2%), large unclassifiable (11%), isolated intraventricular (1.9%), or unclassifiable due to insufficient information (1.3%).

Conclusion

The validity of a-ICH diagnoses is high in both registries. For s-ICH, PPV was higher in DSR, while sensitivity was higher in DNPR. The location of s-ICH was similar to distributions seen in other populations.

Dietary patterns generated by the Treelet Transform and risk of stroke: a Danish cohort study

OBJECTIVE

To relate empirically derived dietary patterns identified using the Treelet Transform (TT) to risk of stroke.

DESIGN

A prospective cohort study using the Danish Diet, Cancer and Health cohort. Dietary information was obtained in 1993-1997 using a validated semi-quantitative FFQ. Incident stroke diagnoses, obtained from the Danish National Patient Register, were verified by record review. Dietary patterns were generated using TT, and participants were categorised into quintiles based on their adherence to each pattern. Sex-specific Cox proportional hazard models estimated associations between dietary patterns and stroke.

SETTING

Denmark.

PARTICIPANTS

55 061 men and women aged 50-64 years at the time of enrolment.

RESULTS

Three dietary patterns explaining 15·4 % of the total variance were identified: a Prudent pattern, a Western pattern and a Wine & Snacks pattern. During a follow-up time of 10 years, 1513 cases occurred. Comparing the highest to lowest quintiles of intake, adherence to a Prudent pattern was inversely associated with stroke (HRmen 0·74, 95 % CI 0·60, 0·91; HRwomen 0·82, 95 % CI 0·62, 1·08), while adherence to a Western pattern was associated with greater risk (HRmen 1·61, 95 % CI 1·23, 2·10; HRwomen 2·01, 95 % CI 1·48, 2·72). No association was found for a Wine & Snacks pattern for women, but a weak inverse association was found for men (HR 0·81, 95 % CI 0·67, 0·99).

CONCLUSIONS

The results of this study are broadly in line with current recommendations for a healthy diet to prevent stroke.

Validity of Acute Cardiovascular Outcome Diagnoses Recorded in European Electronic Health Records: A Systematic Review

BACKGROUND

Electronic health records are widely used in cardiovascular disease research. We appraised the validity of stroke, acute coronary syndrome and heart failure diagnoses in studies conducted using European electronic health records.

METHODS

Using a prespecified strategy, we systematically searched seven databases from dates of inception to April 2019. Two reviewers independently completed study selection, followed by partial parallel data extraction and risk of bias assessment. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value estimates were narratively synthesized and heterogeneity between sensitivity and PPV estimates were assessed using I2.

RESULTS

We identified 81 studies, of which 20 validated heart failure diagnoses, 31 validated acute coronary syndrome diagnoses with 29 specifically recording estimates for myocardial infarction, and 41 validated stroke diagnoses. Few studies reported specificity or negative predictive value estimates. Sensitivity was ≤66% in all but one heart failure study, ≥80% for 91% of myocardial infarction studies, and ≥70% for 73% of stroke studies. PPV was ≥80% in 74% of heart failure, 88% of myocardial infarction, and 70% of stroke studies. PPV by stroke subtype was variable, at ≥80% for 80% of ischaemic stroke but only 44% of haemorrhagic stroke. There was considerable heterogeneity (I2 >75%) between sensitivity and PPV estimates for all diagnoses.

CONCLUSION

Overall, European electronic health record stroke, acute coronary syndrome and heart failure diagnoses are accurate for use in research, although validity estimates for heart failure and individual stroke subtypes were lower. Where possible, researchers should validate data before use or carefully interpret the results of previous validation studies for their own study purposes.

Thromboembolic and bleeding outcomes in patients with atrial fibrillation and valvular heart disease: A descriptive nationwide cohort study

AIMS

The risks of thromboembolism and bleeding in patients with atrial fibrillation (AF) and valvular heart disease (VHD) are sparsely described. We described the risk of events in non-anticoagulated and anticoagulated patients with AF and VHD according to the evaluated heart valves, rheumatic or artificial valve classification (EHRA classification), EHRA Type 1 and Type 2 VHD, and within subgroups of EHRA Type 1 and Type 2 VHD.

METHODS AND RESULTS

Cohort study of AF patients with coexisting VHD, identified in nationwide Danish registries from 2000 to 2018. Risk of thromboembolism and bleeding after 1 year of follow-up were calculated in each group. We identified 28 770 incident AF patients with VHD. Not surprisingly, we observed the highest risks of thromboembolism in the non-anticoagulated AF patients with EHRA Type 1 and Type 2 VHD (4.9% vs 2.6% and 3.2% vs 1.9%) and the highest risks of bleeding in the anticoagulated AF patients with EHRA Type 1 and Type 2 VHD (6.6% vs 4.3% and 6.1% vs 4.9%). However, within the subgroups of AF patients with EHRA Type 1 and Type 2 VHD, we observed a large proportion of non-anticoagulated patients (32.9%-49.2%), despite a CHA₂ DS₂ -VASc score of 2≤ in the majority of these patients (81.9%-95.6%).

CONCLUSIONS

When using data reflecting contemporary clinical practice, we observed markedly different risks of thromboembolism and bleeding in EHRA Type 1 and Type 2 VHD. Additionally, we observed a potential underuse of oral anticoagulation within the subgroups of AF patients with EHRA Type 1 and Type 2 VHD, underlining need for further attention on this patient group.

Risk of Major Adverse Cardiovascular Events, Severe Hypoglycemia, and All-Cause Mortality for Widely Used Antihyperglycemic Dual and Triple Therapies for Type 2 Diabetes Management: A Cohort Study of All Danish Users

OBJECTIVE

The vast number of antihyperglycemic medications and growing amount of evidence make clinical decision making difficult. The aim of this study was to investigate the safety of antihyperglycemic dual and triple therapies for type 2 diabetes management with respect to major adverse cardiovascular events, severe hypoglycemia, and all-cause mortality in a real-life clinical setting.

RESEARCH DESIGN AND METHODS

Cox regression models were constructed to analyze 20 years of data from the Danish National Patient Registry with respect to effect of the antihyperglycemic therapies on the three end points.

RESULTS

A total of 66,807 people with type 2 diabetes were treated with metformin (MET) plus a combination of second- and third-line therapies. People on MET plus sulfonylurea (SU) had the highest risk of all end points, except for severe hypoglycemia, for which people on MET plus basal insulin (BASAL) had a higher risk. The lowest risk of major adverse cardiovascular events was seen for people on a regimen including a glucagon-like peptide 1 (GLP-1) receptor agonist. People treated with MET, GLP-1, and BASAL had a lower risk of all three end points than people treated with MET and BASAL, especially for severe hypoglycemia. The lowest risk of all three end points was, in general, seen for people treated with MET, sodium-glucose cotransporter 2 inhibitor, and GLP-1.

CONCLUSIONS

Findings from this study do not support SU as the second-line treatment choice for patients with type 2 diabetes. Moreover, the results indicate that adding a GLP-1 in people treated with MET and BASAL could be considered, especially if those people suffer from severe hypoglycemia.

Associations between adjustment disorder and hospital-based infections in the Danish population

OBJECTIVE

There is some evidence that posttraumatic stress disorder (PTSD) is associated with increased risk of infections, and it is unknown whether adjustment disorder is as well. We assessed the association between adjustment disorder and subsequent infections, and assessed additive interaction with sex.

METHODS

The study population included a nationwide cohort of all Danish-born residents of Denmark diagnosed with adjustment disorder between 1995 and 2011, and an age- and sex-matched general population comparison cohort. We compared rates of infections requiring inpatient or outpatient hospitalization in the two cohorts. We fit Cox proportional hazards models to compute adjusted hazard ratios (aHR) for the associations between adjustment disorder and 32 types of infections, and calculated interaction contrasts to assess interaction between adjustment disorder and sex.

RESULTS

Adjustment disorder was associated with increased rates of infections overall (n = 19,838 infections, aHR = 1.8, 95% confidence interval = 1.8. 1.9), and increased rates of each individual infection type (aHRs for 30 infections ranged from 1.5 to 2.3), adjusting for baseline psychiatric and somatic comorbidities and marital status. For many infection types (e.g., skin infections, pneumonia), interaction contrasts indicated rate differences were greater among men than women, while for two (urinary tract infections and sexually transmitted infections), rate differences were greater for women.

CONCLUSIONS

These findings are consistent with studies examining the relationship between psychological stress and infections, and between PTSD and infections. They may be explained by a combination of the triggering of unhealthy behaviors as well as immune responses to stress.

Substitutions between potatoes and other vegetables and risk of ischemic stroke

PURPOSE

Intake of vegetables has been associated with a lower risk of ischemic stroke in observational studies controlling for total energy intake. However, adjustment for energy intake introduces a substitution aspect, which affects the interpretation of the results. We investigated replacement of potatoes with other vegetables, substitutions between vegetable subgroups, and risk of ischemic stroke and ischemic stroke subtypes.

METHODS

The Danish Diet, Cancer and Health cohort included 57,053 participants aged 50-64 years at recruitment in 1993-1997. Diet was assessed from a validated 192-item semi-quantitative food frequency questionnaire. We calculated hazard ratios (HR) with 95% confidence intervals (CI) for the incidence of ischemic stroke using Cox proportional hazard regression.

RESULTS

During 13.5 years of follow-up, 1879 cases of ischemic stroke were identified including 319 cases of large-artery atherosclerosis and 844 cases of small-vessel occlusion. The adjusted HR for total ischemic stroke associated with food substitutions of equal amounts (500 g/week) was 0.86 (95% CI 0.76, 0.97) for replacement of potatoes with fruiting vegetables and 0.92 (95% CI 0.84, 1.02) for replacement of potatoes with other root vegetables. The HR for replacing potatoes with the sum of other vegetables was 0.95 (95% CI 0.90, 1.00). Substitution of cabbage for either potatoes, fruiting vegetables or other root vegetables was associated with a statistically non-significant higher risk of ischemic stroke. The patterns of associations were similar for ischemic stroke subtypes and for equivalent substitutions using isocaloric amounts.

CONCLUSION

Replacing potatoes with fruiting vegetables was associated with a lower risk of ischemic stroke.

Thromboembolism and bleeding complications in anticoagulated patients with atrial fibrillation and native aortic or mitral valvular heart disease: a descriptive nationwide cohort study

AIMS

To describe the risks of thromboembolism and major bleeding complications in anticoagulated patients with atrial fibrillation (AF) and native aortic or mitral valvular heart disease using data reflecting clinical practice.

METHODS AND RESULTS

Descriptive cohort study of anticoagulated patients with incident AF and native aortic or mitral valvular heart disease, identified in nationwide Danish registries from 2000 to 2018. A total of 10 043 patients were included, of which 5190 (51.7%) patients had aortic stenosis, 1788 (17.8%) patients had aortic regurgitation, 327 (3.3%) patients had mitral stenosis, and 2738 (27.3%) patients had mitral regurgitation. At 1 year after AF diagnosis, the risk of thromboembolism was 4.6% in patients with mitral stenosis taking a vitamin K antagonist (VKA), and 2.6% in patients with aortic stenosis taking a VKA or non-vitamin K antagonist oral anticoagulant (NOAC). For patients with aortic or mitral regurgitation, the risks of thromboembolism ranged between 1.5%-1.8% in both treatment groups. For the endpoint of major bleeding, the risk was ∼5.5% in patients with aortic stenosis or mitral stenosis treated with a VKA, and 3.3-4.0% in patients with aortic or mitral regurgitation. For patients treated with a NOAC, the risk of major bleeding was 3.7% in patients with aortic stenosis and ∼2.5% in patients with aortic or mitral regurgitation.

CONCLUSION

When using data reflecting contemporary clinical practice, our observations suggested that 1 year after a diagnosis of AF, anticoagulated patients with aortic or mitral valvular heart disease had dissimilar risk of thromboembolism and major bleeding complications. Specifically, patients with aortic stenosis or mitral stenosis were high-risk subgroups. This observation may guide clinicians regarding intensity of clinical follow-up.

Prediction of Sex-Specific Suicide Risk Using Machine Learning and Single-Payer Health Care Registry Data From Denmark

Importance

Suicide is a public health problem, with multiple causes that are poorly understood. The increased focus on combining health care data with machine-learning approaches in psychiatry may help advance the understanding of suicide risk.

Objective

To examine sex-specific risk profiles for death from suicide using machine-learning methods and data from the population of Denmark.

Design, Setting, and Participants

A case-cohort study nested within 8 national Danish health and social registries was conducted from January 1, 1995, through December 31, 2015. The source population was all persons born or residing in Denmark as of January 1, 1995. Data were analyzed from November 5, 2018, through May 13, 2019.

Exposures

Exposures included 1339 variables spanning domains of suicide risk factors.

Main Outcomes and Measures

Death from suicide from the Danish cause of death registry.

Results

A total of 14 103 individuals died by suicide between 1995 and 2015 (10 152 men [72.0%]; mean [SD] age, 43.5 [18.8] years and 3951 women [28.0%]; age, 47.6 [18.8] years). The comparison subcohort was a 5% random sample (n = 265 183) of living individuals in Denmark on January 1, 1995 (130 591 men [49.2%]; age, 37.4 [21.8] years and 134 592 women [50.8%]; age, 39.9 [23.4] years). With use of classification trees and random forests, sex-specific differences were noted in risk for suicide, with physical health more important to men's suicide risk than women's suicide risk. Psychiatric disorders and possibly associated medications were important to suicide risk, with specific results that may increase clarity in the literature. Generally, diagnoses and medications measured 48 months before suicide were more important indicators of suicide risk than when measured 6 months earlier. Individuals in the top 5% of predicted suicide risk appeared to account for 32.0% of all suicide cases in men and 53.4% of all cases in women.

Conclusions and Relevance

Despite decades of research on suicide risk factors, understanding of suicide remains poor. In this study, the first to date to develop risk profiles for suicide based on data from a full population, apparent consistency with what is known about suicide risk was noted, as well as potentially important, understudied risk factors with evidence of unique suicide risk profiles among specific subpopulations.

Risk of major cardiovascular events, severe hypoglycaemia, and all-cause mortality for users of insulin degludec versus insulin glargine U100-A Danish cohort study

AIMS

Real-world evidence of the safety of insulin degludec compared with insulin glargine U100 is sparse. This study sought to investigate the risk of major cardiovascular events, severe hypoglycaemia, and all-cause mortality after initiation of degludec or glargine U100 in the population of Denmark.

MATERIALS AND METHODS

All Danish people with diabetes initiating treatment on degludec (n=5159) or glargine (n=4041) in 2016 to 2017 were included in the study. The effect of insulin treatment on the endpoints of major cardiovascular events, severe hypoglycaemia, and all-cause mortality was analysed with Cox proportional hazard models. The models were adjusted for age, sex, diabetes duration, diabetes type, highest completed education, and annual income. The model of severe hypoglycaemia was also adjusted for severe hypoglycaemia prior to baseline. The model of mortality was also adjusted for history of alcohol abuse, use of antidepressants, use of opioids, and use of anxiolytics. Lastly, the models of major cardiovascular events and mortality were also adjusted for Charlson comorbidity index.

RESULTS

Use of degludec resulted in an almost twofold decrease in risk of death (hazard rate [HR]: 0.54, 95% CI: 0.44-0.65) compared with use of glargine. No statistically significant risk changes were found for major cardiovascular events (HR: 0.86, 95% CI: 0.62-1.19) and severe hypoglycaemia (HR: 1.13, 95% CI: 0.66-1.93). The proportion of cause of death due to malignant neoplasm of pancreas was almost doubled for glargine compared with degludec.

CONCLUSIONS

These results indicate that insulin degludec has a safer profile with respect to all-cause mortality as compared with insulin glargine U100.

Substitutions of Oatmeal and Breakfast Food Alternatives and the Rate of Stroke

Background and Purpose- Studies indicate that consuming breakfast every day, and particularly oatmeal, is associated with lower risk of stroke. However, few studies have considered replacement foods when considering foods usually consumed at breakfast. We, therefore, aimed to model substitutions between the breakfast food products oatmeal, eggs, yogurt, or white bread and subsequent risk of stroke. Methods- Participants from the Danish cohort study (Diet, Cancer and Health; n=55 095) were followed for 13.4 years, during which 2260 subjects experienced a first-ever stroke. Breakfast foods were assessed using a validated 192-item food-frequency questionnaire at baseline. Cox proportional hazards models were used to estimate adjusted hazard ratios and 95% CIs for associations between hypothetical substitutions of standard portion sizes of breakfast foods and stroke. Results- Modeling replacement of white bread or eggs with oatmeal was associated with a lower rate of total stroke (hazard ratio [HR]=0.96 [95% CI, 0.95-0.98]; HR=0.96 [95% CI, 0.93-0.98], respectively), total ischemic stroke (HR=0.96 [95% CI, 0.94-0.98]; HR=0.96 [95% CI, 0.94-0.99], respectively), and ischemic stroke due to small-artery occlusion (HR=0.95 [95% CI, 0.93-0.98]; HR=0.95 [95% CI, 0.91-0.99], respectively). Furthermore, modeling replacement of eggs with oatmeal was associated with a lower rate of total hemorrhagic stroke (HR=0.94 [95% CI, 0.89-0.99]). Modeling replacement of yogurt with oatmeal was not associated with stroke. Conclusions- Our findings suggest that a diet containing oatmeal instead of white bread or eggs may be associated with a lower rate of stroke.

Vascular Diseases In Patients With Chronic Myeloproliferative Neoplasms - Impact Of Comorbidity

Background

Patients with chronic myeloproliferative neoplasms (MPNs), including essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF), are at high risk of vascular complications. However, the magnitude of this is risk not well known and the possible effect of comorbidity is poorly understood.

Aim

Our aim was to compare the risk of vascular diseases in patients with MPNs and matched comparisons from the general population and to study the effect modification of comorbidity.

Methods

We followed 3087 patients with ET, 6076 with PV, 3719 with PMF or unspecified MPN, and age- and sex-matched general population comparisons to estimate the risks of cardiovascular diseases such as myocardial infarction and stroke. We computed 5-year cumulative incidences (risks) for vascular disease in patients with MPNs and comparisons as well as 1-year and 5-year risks, risk differences, and hazard ratios (HRs) for vascular diseases comparing rates in each group of patients with their comparison cohort by level of comorbidity based on the Charlson Comorbidity Index (CCI) [score of 0 (low comorbidity), of 1–2 (moderate comorbidity), and of >2 (severe comorbidity)], as well as other comorbid conditions.

Results

The overall 5-year risk of vascular disease ranged from 0.5% to 7.7% in patients with MPNs, which was higher than the risk in the general population. In the same period, the adjusted HRs for vascular disease were 1.3 to 3.7 folds higher in patients with MPNs compared to the general population. An increase in CCI score was associated with an equally increased rate of most types of vascular diseases during the first 5 years of follow-up in both MPN and comparisons.

Conclusion

Patients with MPNs have a higher risk of vascular diseases during the first 5 years than that of the general population; however, comorbidity modifies the rates similarly in MPN and in the general population.

Usefulness of CHA2DS2-VASc Score to Predict Stroke Risk Independent of Atrial Fibrillation

The CHA₂DS₂-VASc score is used to predict stroke risk among patients with atrial fibrillation (AF). We examined whether a CHA₂DS₂-VASc score predicts stroke risk among individuals without hospital-diagnosed AF and quantified the magnitude of the association in comparison to AF patients. We used data from population-based medical registries (1995 to 2005) covering all Danish hospitals to identify patients diagnosed with AF (n = 122,980). We matched ≤5 non-AF individuals (n = 612,723) to each AF patient on the individual risk factors included in the CHA₂DS₂-VASc score. We calculated 10-year absolute risk of ischemic and all-cause stroke in AF and non-AF individuals and compared the stroke risk between cohorts within strata of CHA₂DS₂-VASc scores using Cox regression. The 10-year risk of ischemic/all-cause stroke was 4.4%/8.8% among non-AF individuals and 6.2%/12% in AF patients, corresponding to a risk difference of 1.8% for ischemic stroke and 3.3% for all-cause stroke. In both cohorts, the stroke risk correlated with increasing CHA₂DS₂-VASc scores. However, in individuals with CHA₂DS₂-VASc scores ≥5 who were <75 years or male, the absolute risk of ischemic stroke in individuals without AF exceeded the risk in AF patients. In the same subgroups, the hazard ratio approached unity. Similar results were observed for all-cause stroke. The CHA₂DS₂-VASc score was associated with 10-year stroke risk also among individuals without hospital-diagnosed AF. In conclusion, primary prophylactic anticoagulation therapy may be relevant in male and younger non-AF individuals with CHA₂DS₂-VASc scores ≥5. These findings should be confirmed in clinical trials.

Diagnostic Value of Oligoclonal Bands in Children: A Nationwide Population-Based Cohort Study

OBJECTIVE

We evaluated the diagnostic value of cerebrospinal fluid oligoclonal bands in individuals less than 18 years of age.

METHODS

In a nationwide population-based setting, we retrieved data on 2055 children's oligoclonal band examination, including concordant cerebrospinal fluid biomarkers, during 1994 to 2017. Case ascertainment was by review of medical records and diagnostic codes. We used Fisher's exact test to explore distribution differences of oligoclonal band positivity in acquired demyelinating syndromes (ADS) before and after age 12 years and calculated the sensitivity, specificity, positive predictive value, and negative predictive value of oligoclonal bands to distinguish ADS from the other diagnostic groups.

RESULTS

Median age at oligoclonal band examination was 15.2 years (range = 1.8 to 18.0), and 10% had presence of cerebrospinal fluid oligoclonal bands. Oligoclonal band positivity was the highest in ADS (52%), but it was age dependent: 21% in children with ADS before age 12 years and 68% in children aged 12 through 17 years (P < 0.0001) owing to the higher incidence of multiple sclerosis in the latter. Cerebrospinal fluid oligoclonal bands were not predictive of ADS before age 12 years compared with the other diagnostic groups. However, cerebrospinal fluid oligoclonal bands in children aged 12 through 17 years were highly predictive of ADS compared with central nervous system infections and non-ADS immune-mediated central nervous system diseases (positive predictive value: 0.89; 95% confidence interval = 0.82 to 0.94; P < 0.0001), but negative oligoclonal bands were not discriminatory (negative predictive value: P = 0.17).

CONCLUSIONS

In a clinical setting, cerebrospinal fluid oligoclonal band examination may be of higher yield in children aged 12 through 17 years if there is clinical suspicion of multiple sclerosis, and in such circumstances a positive test supports a diagnosis of multiple sclerosis.