Predictive values of acute coronary syndrome discharge diagnoses differed in the Danish National Patient Registry

Positive predictive value of cardiovascular diagnoses in the Danish National Patient Registry: a validation study

OBJECTIVE

The majority of cardiovascular diagnoses in the Danish National Patient Registry (DNPR) remain to be validated despite extensive use in epidemiological research. We therefore examined the positive predictive value (PPV) of cardiovascular diagnoses in the DNPR.

DESIGN

Population-based validation study.

SETTING

1 university hospital and 2 regional hospitals in the Central Denmark Region, 2010-2012.

PARTICIPANTS

For each cardiovascular diagnosis, up to 100 patients from participating hospitals were randomly sampled during the study period using the DNPR.

MAIN OUTCOME MEASURE

Using medical record review as the reference standard, we examined the PPV for cardiovascular diagnoses in the DNPR, coded according to the International Classification of Diseases, 10th Revision.

RESULTS

A total of 2153 medical records (97% of the total sample) were available for review. The PPVs ranged from 64% to 100%, with a mean PPV of 88%. The PPVs were ≥90% for first-time myocardial infarction, stent thrombosis, stable angina pectoris, hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, takotsubo cardiomyopathy, arterial hypertension, atrial fibrillation or flutter, cardiac arrest, mitral valve regurgitation or stenosis, aortic valve regurgitation or stenosis, pericarditis, hypercholesterolaemia, aortic dissection, aortic aneurysm/dilation and arterial claudication. The PPVs were between 80% and 90% for recurrent myocardial infarction, first-time unstable angina pectoris, pulmonary hypertension, bradycardia, ventricular tachycardia/fibrillation, endocarditis, cardiac tumours, first-time venous thromboembolism and between 70% and 80% for first-time and recurrent admission due to heart failure, first-time dilated cardiomyopathy, restrictive cardiomyopathy and recurrent venous thromboembolism. The PPV for first-time myocarditis was 64%. The PPVs were consistent within age, sex, calendar year and hospital categories.

CONCLUSIONS

The validity of cardiovascular diagnoses in the DNPR is overall high and sufficient for use in research since 2010.

Depression following acute coronary syndrome: a Danish nationwide study of potential risk factors

PURPOSE

Depression is common following acute coronary syndrome, and thus, it is important to provide knowledge to improve prevention and detection of depression in this patient group. The objectives of this study were to examine: (1) whether indicators of stressors and coping resources were risk factors for developing depression early and later after an acute coronary syndrome and (2) whether prior depression modified these associations.

METHODS

The study was a register-based cohort study, which includes 87,118 patients with a first time diagnosis of acute coronary syndrome during the period 2001-2009 in Denmark. Cox regression models were used to analyse hazard ratios (HRs) for depression.

RESULTS

1.5 and 9.5 % develop early (≤30 days) and later (31 days-2 years) depression after the acute coronary syndrome. Among all patients with depression, 69.2 % had first onset depression, while 30.8 % developed a recurrent depression. Most patient characteristics (demographic factors, socioeconomic status, psychosocial factors, health-related behavioural factors, somatic comorbidities, and severity of acute coronary syndrome) were significantly associated with increased HRs for both early and later depressions. Prior depression modified most of these associations in such a way that the association was attenuated in patients with a prior depression.

CONCLUSION

Our results indicate that first time and recurrent depression following acute coronary syndrome have different risk profiles. This is important knowledge that may be used to focus future interventions for prevention and detection.

Substitution of meat and fish with vegetables or potatoes and risk of myocardial infarction

Red meat has been suggested to be adversely associated with risk of myocardial infarction (MI), whereas vegetable consumption has been found to be protective. The aim of this study was to investigate substitutions of red meat, poultry and fish with vegetables or potatoes for MI prevention. We followed up 29 142 women and 26 029 men in the Danish Diet, Cancer and Health study aged 50-64 years with no known history of MI at baseline. Diet was assessed by a validated 192-item FFQ at baseline. Adjusted Cox proportional hazard models were used to calculate hazard ratios (HR) and 95 % CI for MI associated with specified food substitutions of 150 g/week. During a median follow-up of 13·6 years, we identified 656 female and 1694 male cases. Among women, the HR for MI when replacing red meat with vegetables was 0·94 (95 % CI 0·90, 0·98). Replacing fatty fish with vegetables was associated with a higher risk of MI (HR 1·23; 95 % CI 1·05, 1·45), whereas an inverse, statistically non-significant association was found for lean fish (HR 0·93; 95 % CI 0·83, 1·05). Substituting poultry with vegetables was not associated with risk of MI (HR 1·00; 95 % CI 0·90, 1·11). Findings for substitution with potatoes were similar to findings for vegetables. Among men, a similar pattern was observed, but the associations were weak and mostly statistically non-significant. This study suggests that replacing red meat with vegetables or potatoes is associated with a lower risk of MI, whereas replacing fatty fish with vegetables or potatoes is associated with a higher risk of MI.

Evaluation of algorithms for registry-based detection of acute myocardial infarction following percutaneous coronary intervention

Background

Registry-based monitoring of the safety and efficacy of interventions in patients with ischemic heart disease requires validated algorithms.

Objective

We aimed to evaluate algorithms to identify acute myocardial infarction (AMI) in the Danish National Patient Registry following percutaneous coronary intervention (PCI).

Methods

Patients enrolled in clinical drug-eluting stent studies at the Department of Cardiology, Aarhus University Hospital, Denmark, from January 2006 to August 2012 were included. These patients were evaluated for ischemic events, including AMI, during follow-up using an end point committee adjudication of AMI as reference standard.

Results

Of 5,719 included patients, 285 patients suffered AMI within a mean follow-up time of 3 years after stent implantation. An AMI discharge diagnosis (primary or secondary) from any acute or elective admission had a sensitivity of 95%, a specificity of 93%, and a positive predictive value of 42%. Restriction to acute admissions decreased the sensitivity to 94% but increased the specificity to 98% and the positive predictive value to 73%. Further restriction to include only AMI as primary diagnosis from acute admissions decreased the sensitivity further to 82%, but increased the specificity to 99% and the positive predictive value to 81%. Restriction to patients admitted to hospitals with a coronary angiography catheterization laboratory increased the positive predictive value to 87%.

Conclusion

Algorithms utilizing additional information from the Danish National Patient Registry yield different sensitivities, specificities, and predictive values in registry-based detection of AMI following PCI. We were able to identify AMI following PCI with moderate-to-high validity. However, the choice of algorithm will depend on the specific study purpose.

Do hip prosthesis related infection codes in administrative discharge registers correctly classify periprosthetic hip joint infection?

PURPOSE

Administrative discharge registers could be a valuable and easily accessible single-sources for research data on periprosthetic hip joint infection. The aim of this study was to estimate the positive predictive value of the International Classification of Disease 10th revision (ICD-10) periprosthetic hip joint infection diagnosis code in the Danish National Patient Register.

METHODS

Patients were identified with an ICD-10 discharge diagnosis code of T84.5 ("Infection and inflammatory reaction due to internal joint prosthesis") in association with hip-joint associated surgical procedure codes in The Danish National Patient Register. Medical records of the identified patients (n = 283) were verified for the existence of a periprosthetic hip joint infection. Positive predictive values with 95% confidence intervals (95% CI) were calculated.

RESULTS

A T84.5 diagnosis code irrespective of the associated surgical procedure code had a positive predictive value of 85% (95% CI: 80-89). Stratified to T84.5 in combination with an infection-specific surgical procedure code the positive predictive value increased to 86% (95% CI: 80-91), and in combination with a noninfection-specific surgical procedure code decreased to 82% (95% CI: 72-89).

CONCLUSIONS

Misclassification must be expected and taken into consideration when using administrative discharge registers for epidemiological research on periprosthetic hip joint infection. We believe that the periprosthetic hip joint infection diagnosis code can be of use in future single-source register based studies, but preferably should be used in combination with alternate data sources to ensure higher validity.

Catalog of 199 register-based definitions of chronic conditions

INTRODUCTION

The aim of the current study was to present and discuss a broad range of register-based definitions of chronic conditions for use in register research, as well as the challenges and pitfalls when defining chronic conditions by the use of registers.

MATERIALS AND METHODS

The definitions were defined based on information from nationwide Danish public healthcare registers. Medical and epidemiological specialists identified and grouped relevant diagnosis codes that covered chronic conditions, using the International Classification System version 10 (ICD-10). Where relevant, prescription and other healthcare data were also used to define the chronic conditions.

RESULTS

We identified 199 chronic conditions and subgroups, which were divided into four groups according to a medical judgment of the expected duration of the conditions, as follows. Category I: Stationary to progressive conditions (maximum register inclusion time of diagnosis since the start of the register in 1994). Category II: Stationary to diminishing conditions (10 years of register inclusion after time of diagnosis). Category III: Diminishing conditions (5 years of register inclusion after time of diagnosis). Category IV: Borderline conditions (2 years of register inclusion time following diagnosis). The conditions were primarily defined using hospital discharge diagnoses; however, for 35 conditions, including common conditions such as diabetes, chronic obstructive lung disease and allergy, more complex definitions were proposed based on record linkage between multiple registers, including registers of prescribed drugs and use of general practitioners' services. CONCLUSIONS THIS STUDY PROVIDED A CATALOG OF REGISTER-BASED DEFINITIONS FOR CHRONIC CONDITIONS FOR USE IN HEALTHCARE PLANNING AND RESEARCH, WHICH IS, TO THE AUTHORS' KNOWLEDGE, THE LARGEST CURRENTLY COMPILED IN A SINGLE STUDY.

Dietary intake and adipose tissue content of α-linolenic acid and risk of myocardial infarction: a Danish cohort study

BACKGROUND

Intake of the plant-derived ω-3 (n-3) fatty acid α-linolenic acid (ALA, 18:3; n-3) may reduce coronary heart disease (CHD) risk, but the results of previous studies have been inconsistent.

OBJECTIVE

We aimed to investigate the association between dietary intake of ALA, adipose tissue content of ALA, and risk of incident myocardial infarction (MI).

DESIGN

A total of 57,053 participants, aged 50-64 y, were enrolled in the prospective Danish cohort study Diet, Cancer and Health between 1993 and 1997. Dietary intake of ALA was assessed with the use of a validated semiquantitative food-frequency questionnaire in the full cohort, whereas the adipose tissue content of ALA was determined with the use of gas chromatography in all incident MI cases and in a random sex-stratified sample of the total cohort (n = 3500).

RESULTS

During a median of 17 y of follow-up, we identified 2177 male and 912 female cases of MI. After appropriate exclusions, we included 2124 men and 854 women for analyses of dietary intake of ALA, whereas 1994 men and 770 women were included in the analysis of the adipose tissue content of ALA. In multivariate analyses that were conducted with the use of restricted cubic splines and adjusted for established CHD risk factors, weak positive associations in men and weak U-shaped associations in women were shown between both dietary intake and the adipose tissue content of ALA and risk of MI, but these associations were not statistically significant. Additional adjustments for dietary factors did not influence the observed associations numerically.

CONCLUSION

This study suggests that ALA has no appreciable association with risk of incident MI in either men or women.

Time trend in depression diagnoses among acute coronary syndrome patients and a reference population from 2001 to 2009 in Denmark

Introduction In the last decade a range of recommendations to increase awareness of depression in acute coronary syndrome patients have been published. To test the impact of those recommendations we examine and compare recent time trends in depression among acute coronary syndrome patients and a reference population. Methods 87 218 patients registered with acute coronary syndrome from 2001-2009 in Denmark and a match reference population were followed through hospital registries and medication prescriptions for early (≤30 days), intermediate (31 days to 6 months) and later (6 months to 2 years) depression in the acute coronary syndrome population and overall depression in the reference population. Cox regression models were used to compare hazard ratios (HRs) for depression over calendar years. Results During the study period, 11.0% and 6.2% were diagnosed with depression in the acute coronary syndrome population and in the reference population, respectively. For the acute coronary syndrome population, the adjusted HRs increased for early (HR (95% CI) 1.04 (1.01-1.06)) and intermediate depression (HR (95% CI) 1.01 (1.00-1.03)), whereas the adjusted HRs did not change for later depression (HR (95% CI) 0.99 (0.98-1.00)). For the reference population the adjusted HRs for depression increased through the study period (HR (95% CI) 1.01 (1.01-1.03)). Conclusion Increase in diagnoses of depressions within 6 months of acute coronary syndrome may be explained by increased focus on depression in this patient group in combination with increased awareness of depression in the general population.

Association of fish consumption and dietary intake of marine n-3 PUFA with myocardial infarction in a prospective Danish cohort study

Several studies have investigated the potential benefits of marine n-3 PUFA in CVD, generally suggesting a lower risk of CHD. However, recent trials have questioned these results. This study investigated the association of fish consumption with dietary intake of marine n-3 PUFA with incident myocardial infarction (MI). In a Danish cohort study, 57 053 subjects between 50 and 64 years of age were enrolled from 1993 to 1997. From national registries, we identified all cases of incident MI. Dietary fish consumption was assessed using a semi-quantitative food questionnaire, including twenty-six questions regarding fish intake. In addition, we calculated the intake of total and individual marine n-3 PUFA. During a median follow-up of 17·0 years, we identified 3089 cases of incident MI. For both men and women, a high intake of fatty fish was inversely related to incident MI. Thus, when comparing the highest and the lowest quintile of fatty fish intake, we found a 12 % lower relative risk of MI in men (hazard ratio (HR) 0·88; 95 % CI 0·77, 1·00) and a 22 % lower relative risk in women (HR 0·78; 95 % CI 0·63, 0·96) after adjustments. For women, similar associations were observed for individual and total marine n-3 PUFA. In contrast, intake of lean fish was not associated with MI. In conclusion, incident MI was inversely related to a high intake of fatty fish, but not lean fish. However, test for trends across quintiles was not statistically significant. In general, this study supports the view that consumption of fatty fish may protect against MI.

Five year change in alcohol intake and risk of breast cancer and coronary heart disease among postmenopausal women: prospective cohort study

OBJECTIVE

To test the hypothesis that postmenopausal women who increase their alcohol intake over a five year period have a higher risk of breast cancer and a lower risk of coronary heart disease compared with stable alcohol intake.

DESIGN

Prospective cohort study.

SETTING

Denmark, 1993-2012.

PARTICIPANTS

21 523 postmenopausal women who participated in the Diet, Cancer, and Health Study in two consecutive examinations in 1993-98 and 1999-2003. Information on alcohol intake was obtained from questionnaires completed by participants.

MAIN OUTCOME MEASURES

Incidence of breast cancer, coronary heart disease, and all cause mortality during 11 years of follow-up. Information was obtained from the Danish Cancer Register, Danish Hospital Discharge Register, Danish Register of Causes of Death, and National Central Person Register. We estimated hazard ratios according to five year change in alcohol intake using Cox proportional hazards models.

RESULTS

During the study, 1054, 1750, and 2080 cases of breast cancer, coronary heart disease, and mortality occurred, respectively. Analyses modelling five year change in alcohol intake with cubic splines showed that women who increased their alcohol intake over the five year period had a higher risk of breast cancer and a lower risk of coronary heart disease than women with a stable alcohol intake. For instance, women who increased their alcohol intake by seven or 14 drinks per week (corresponding to one or two drinks more per day) had hazard ratios of breast cancer of 1.13 (95% confidence interval 1.03 to 1.23) and 1.29 (1.07 to 1.55), respectively, compared to women with stable intake, and adjusted for age, education, body mass index, smoking, Mediterranean diet score, parity, number of births, and hormone replacement therapy. For coronary heart disease, corresponding hazard ratios were 0.89 (0.81 to 0.97) and 0.78 (0.64 to 0.95), respectively, adjusted for age, education, body mass index, Mediterranean diet score, smoking, physical activity, hypertension, elevated cholesterol, and diabetes. Results among women who reduced their alcohol intake over the five year period were not significantly associated with risk of breast cancer or coronary heart disease. Analyses of all cause mortality showed that women who increased their alcohol intake from a high intake (≥14 drinks per week) to an even higher intake had a higher mortality risk that women with a stable high intake.

CONCLUSION

In this study of postmenopausal women over a five year period, results support the hypotheses that alcohol intake is associated with increased risk of breast cancer and decreased risk of coronary heart disease.

Intake of whole grains is associated with lower risk of myocardial infarction: the Danish Diet, Cancer and Health Cohort

BACKGROUND

High intake of whole grains has been associated with lower risk of coronary heart disease; however, the research that has been used to evaluate different effects of different whole-grain cereals (e.g., wheat, rye, and oats) has been sparse.

OBJECTIVE

We investigated the association between whole-grain intake in terms of total intake and intakes of different cereals and myocardial infarction.

DESIGN

This prospective study included 54,871 Danish adults aged 50-64 y, of whom 2329 individuals developed myocardial infarction (13.6 y of follow-up). Detailed information on daily intake of whole-grain products was available from a self-administered food-frequency questionnaire, and intakes of total whole grain and whole-grain species (wheat, rye, and oats) were estimated. The association between intake of whole grains and risk of myocardial infarction was examined with the use of a Cox proportional hazards model adjusted for potential confounders.

RESULTS

For both men and women with total whole-grain intake in the highest quartile, lower risks of myocardial infarction were shown [HRs: 0.75 (95% CI: 0.65, 0.86) and 0.73 (95% CI: 0.58, 0.91), respectively] than for individuals with intake in the lowest quartile. When the specific cereal species were considered, rye and oats, but not wheat, were associated with lower myocardial infarction risk in men. No significant associations were seen in women. For total whole-grain products, significantly lower myocardial infarction risks were seen with higher intakes in both men and women. Rye bread (in men and women) and oatmeal (in men) were associated with significantly lower risk of myocardial infarction, whereas no significant association was shown for whole-grain bread, crispbread, and wheat.

CONCLUSION

In this study, we provide support for the hypothesis that whole-grain intake is related to lower risk of myocardial infarction and suggest that the cereals rye and oats might especially hold a beneficial effect.

Substitutions of red meat, poultry and fish and risk of myocardial infarction

Red meat has been suggested to be adversely associated with risk of myocardial infarction (MI), but previous studies have rarely taken replacement foods into consideration. We aimed to investigate optimal substitutions between and within the food groups of red meat, poultry and fish for MI prevention. We followed up 55 171 women and men aged 50-64 years with no known history of MI at recruitment. Diet was assessed by a validated 192-item FFQ at baseline. Adjusted Cox proportional hazard models were used to calculate hazard ratios (HR) and 95 % CI for specified food substitutions of 150 g/week. During a median follow-up time of 13·6 years, we identified 656 female and 1694 male cases. Among women, the HR for replacing red meat with fatty fish was 0·76 (95 % CI 0·64, 0·89), whereas the HR for replacing red meat with lean fish was 1·00 (95 % CI 0·89, 1·14). Similarly, replacing poultry with fatty but not lean fish was inversely associated with MI: the HR was 0·81 (95 % CI 0·67, 0·98) for fatty fish and was 1·08 (95 % CI 0·92, 1·27) for lean fish. The HR for replacing lean with fatty fish was 0·75 (95 % CI 0·60, 0·94). Replacing processed with unprocessed red meat was not associated with MI. Among men, a similar pattern was found, although the associations were not statistically significant. This study suggests that replacing red meat, poultry or lean fish with fatty fish is associated with a lower risk of MI.

Depression After First Hospital Admission for Acute Coronary Syndrome: A Study of Time of Onset and Impact on Survival

We examined incidence of depression after acute coronary syndrome (ACS) and whether the timing of depression onset influenced survival. All first-time hospitalizations for ACS (n = 97,793) identified in the Danish Patient Registry during 2001-2009 and a reference population were followed for depression and mortality via linkage to patient, prescription, and cause-of-death registries until the end of 2012. Incidence of depression (as defined by hospital discharge or antidepressant medication use) and the relationship between depression and mortality were examined using time-to-event models. In total, 19,520 (20.0%) ACS patients experienced depression within 2 years after the event. The adjusted rate ratio for depression in ACS patients compared with the reference population was 1.28 (95% confidence interval (CI): 1.25, 1.30). During 12 years of follow-up, 39,523 (40.4%) ACS patients and 27,931 (28.6%) of the reference population died. ACS patients with recurrent (hazard ratio (HR) = 1.62, 95% CI: 1.57, 1.67) or new-onset (HR = 1.66, 95% CI: 1.60, 1.72) depression had higher mortality rates than patients with no depression. In the reference population, the corresponding relative estimates for recurrent (HR =1.98, 95% CI: 1.92, 2.05) and new-onset (HR = 2.42, 95% CI: 2.31, 2.54) depression were stronger. Depression is common in ACS patients and is associated with increased mortality independently of time of onset, but here the excess mortality associated with depression seemed to be lower in ACS patients than in the reference population.

Leucocyte Telomere Length and Risk of Cardiovascular Disease in a Cohort of 1,397 Danish Men and Women

OBJECTIVES

Short leucocyte telomere length (LTL) might be a risk factor for cardiovascular diseases (CVD). The present study examines the relation between LTL and incident fatal or non-fatal CVD, ischaemic heart disease (IHD) and stroke in a Danish cohort followed for 29 years.

METHODS

In total, 1,397 men and women who participated in health examinations with blood sampling in 1981-1984 were followed for CVD outcomes until the end of 2012 by linkage to national registers. Cox proportional hazard regression models were used to analyse the relation between LTL and CVD adjusting for potential confounding CVD risk factors.

RESULTS

During the follow-up, 603 participants experienced an incident fatal or non-fatal CVD. The survival analysis showed that baseline LTL was not associated with CVD outcomes. In the subanalysis with IHD as outcome, those with middle and short LTL had an increased hazard rate ratio of 1.97 (95% CI 1.31-2.93) and 1.55 (95% CI 1.02-2.35), respectively, which was attenuated when confounding factors were adjusted for. For stroke, the pattern of associations was similar but less precisely estimated.

CONCLUSIONS

In this study short, LTL was not associated with an increased risk of CVD, but modestly associated with an increased risk of IHD.

The Danish National Patient Registry: a review of content, data quality, and research potential

Background

The Danish National Patient Registry (DNPR) is one of the world’s oldest nationwide hospital registries and is used extensively for research. Many studies have validated algorithms for identifying health events in the DNPR, but the reports are fragmented and no overview exists.

Objectives

To review the content, data quality, and research potential of the DNPR.

Methods

We examined the setting, history, aims, content, and classification systems of the DNPR. We searched PubMed and the Danish Medical Journal to create a bibliography of validation studies. We included also studies that were referenced in retrieved papers or known to us beforehand. Methodological considerations related to DNPR data were reviewed.

Results

During 1977–2012, the DNPR registered 8,085,603 persons, accounting for 7,268,857 inpatient, 5,953,405 outpatient, and 5,097,300 emergency department contacts. The DNPR provides nationwide longitudinal registration of detailed administrative and clinical data. It has recorded information on all patients discharged from Danish nonpsychiatric hospitals since 1977 and on psychiatric inpatients and emergency department and outpatient specialty clinic contacts since 1995. For each patient contact, one primary and optional secondary diagnoses are recorded according to the International Classification of Diseases. The DNPR provides a data source to identify diseases, examinations, certain in-hospital medical treatments, and surgical procedures. Long-term temporal trends in hospitalization and treatment rates can be studied. The positive predictive values of diseases and treatments vary widely (<15%–100%). The DNPR data are linkable at the patient level with data from other Danish administrative registries, clinical registries, randomized controlled trials, population surveys, and epidemiologic field studies – enabling researchers to reconstruct individual life and health trajectories for an entire population.

Conclusion

The DNPR is a valuable tool for epidemiological research. However, both its strengths and limitations must be considered when interpreting research results, and continuous validation of its clinical data is essential.

Effectiveness of an early versus a conservative invasive treatment strategy in acute coronary syndromes: a nationwide cohort study

BACKGROUND

Randomized clinical trials have found that early invasive strategies reduce mortality, myocardial infarction (MI), and rehospitalization compared with a conservative invasive approach in acute coronary syndromes (ACSs), but the effectiveness of such strategies in real-world settings is unknown.

OBJECTIVE

To investigate adverse cardiovascular outcomes of an early versus a conservative invasive strategy in a national cohort of patients with ACSs.

DESIGN

Retrospective cohort study.

SETTING

Administrative health care data on hospitalizations, procedures, and outcomes abstracted from the Danish national registries and covering all acute invasive procedures in patients presenting with an ACS.

PATIENTS

19 704 propensity score-matched patients hospitalized with a first ACS between 1 January 2005 and 31 December 2011.

MEASUREMENTS

Risk for cardiac death or rehospitalization for MI within 60 days of hospitalization.

RESULTS

Compared with a conservative approach, early invasive strategies were associated with a lower risk for cardiac death (cumulative incidence, 5.9% vs. 7.6%; adjusted hazard ratio [HR], 0.75 [95% CI, 0.66 to 0.84]; P < 0.001). Similar results were found for rehospitalization for MI (cumulative incidence, 3.4% vs. 5.0%; adjusted odds ratio, 0.67 [CI, 0.58 to 0.77]; P < 0.001) and all-cause death (cumulative incidence, 7.3% vs. 10.6%; adjusted HR, 0.65 [CI, 0.59 to 0.72]; P < 0.001).

LIMITATION

Potential residual confounding due to lack of core clinical variables.

CONCLUSION

In this real-world cohort of patients with a first hospitalization for an ACS, the use of an early invasive treatment strategy was associated with a lower risk for cardiac death and rehospitalization for MI compared with a conservative invasive approach.

PRIMARY FUNDING SOURCE

Department of Cardiology, University Hospital Gentofte.

Ethnic inequalities in acute myocardial infarction and stroke rates in Norway 1994-2009: a nationwide cohort study (CVDNOR)

Background

Immigrants to Norway from South Asia and Former Yugoslavia have high levels of cardiovascular disease (CVD) risk factors. Yet, the incidence of CVD among immigrants in Norway has never been studied. Our aim was to study the burden of acute myocardial infarction (AMI) and stroke among ethnic groups in Norway.

Methods

We studied the whole Norwegian population (n = 2 637 057) aged 35–64 years during 1994–2009. The Cardiovascular Disease in Norway (CVDNOR) project provided information about all AMI and stroke hospital stays for this period, as well as deaths outside hospital through linkage to the Cause of Death Registry. The direct standardization method was used to estimate age standardized AMI and stroke event rates for immigrants and ethnic Norwegians. Rate ratios (RR) with ethnic Norwegians as reference were calculated using Poisson regression.

Results

The highest risk of AMI was seen in South Asians (men RR = 2.27; 95 % CI 2.08–2.49; women RR = 2.10; 95 % CI 1.76–2.51) while the lowest was seen in East Asians (RR = 0.38 in both men (95 % CI 0.25–0.58) and women (95 % CI 0.18–0.79)). Immigrants from Former Yugoslavia and Central Asia also had increased risk of AMI compared to ethnic Norwegians. South Asians had increased risk of stroke (men RR = 1.26; 95 % CI 1.10–1.44; women RR = 1.58; 95 % CI 1.32–1.90), as did men from Former Yugoslavia, Sub-Saharan Africa and women from Southeast Asia.

Conclusions

Preventive measures should be aimed at reducing the excess numbers of CVD among immigrants from South Asia and Former Yugoslavia.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2412-z) contains supplementary material, which is available to authorized users.

Substantial differences in initiation of oral anticoagulant therapy and clinical outcome among non-valvular atrial fibrillation patients treated in inpatient and outpatient settings

AIMS

Patients with atrial fibrillation (AF) are encountered and treated in different healthcare settings, which may affect the quality of care. We investigated the use of oral anticoagulant (OAC) therapy and the risk of thrombo-embolism (TE) and bleeding, according to the healthcare setting.

METHODS AND RESULTS

Using national Danish registers, we categorized non-valvular AF patients (2002-11) according to the setting of their first-time AF contact: hospitalization (inpatients), ambulatory (outpatients), or emergency department (ED). Event rates and hazard ratios (HRs), calculated using Cox regression analysis, were estimated for outcomes of TE and bleeding. We included 116 051 non-valvular AF patients [mean age 71.9 years (standard deviation 14.1), 51.3% males], of whom 55.2% were inpatients, 41.9% outpatients, and 2.9% ED patients. OAC therapy 180 days after AF diagnosis among patients with a CHADS2 ≥ 2 was 42.1, 63.0, and 32.4%, respectively. Initiation of OAC therapy was only modestly influenced by CHADS2 and HAS-BLED scores, regardless of the healthcare setting. The rate of TE was 4.30 [95% confidence interval (CI) 4.21-4.40] per 100 person-years for inpatients, 2.28 (95% CI 2.22-2.36) for outpatients, and 2.30 (95% CI 2.05-2.59) for ED patients. The adjusted HR of TE, with inpatients as reference, was 0.74 (95% CI 0.71-0.77) for outpatients and 0.89 (95% CI 0.79-1.01) for ED patients.

CONCLUSION

In a nationwide cohort of non-valvular AF patients, outpatients were much more likely to receive OAC therapy and had a significantly lower risk of stroke/TE compared with inpatients and ED patients. However, across all settings investigated, OAC therapy was far from optimal.

Healthcare Contacts after Myocardial Infarction According to Mental Health and Socioeconomic Position: A Population-Based Cohort Study

OBJECTIVE

To examine the long-term use of healthcare contacts to general practice (GP) and hospital after a first-time myocardial infarction (MI) according to mental health and socioeconomic position.

METHODS

Population-based cohort study of all patients discharged with first-time MI in the Central Denmark Region in 2009 (n=908) using questionnaires and nationwide registers. We estimated adjusted incidence rates and incidence rate ratios (IRR) for GP and hospital contacts according to depressive and anxiety symptoms, educational level and cohabitation status.

RESULTS

During the 24-month period after the MI, patients with anxiety symptoms had 24% more GP contacts (adjusted IRR 1.24, 95% confidence interval (CI) 1.12-1.36) than patients with no anxiety symptoms. In contrast, patients with depressive symptoms (1.05, 0.94-1.16) and with short and medium education (<10 years: 0.96, 0.84-1.08; 10-12 years: 0.91, 0.80-1.03) and patients living alone (0.95, 0.87-1.04) had the same number of GP contacts as their counterparts (patients with no depressive symptoms, with long education [>12 years] and patients living with a partner). During the first 6 months after the MI, patients living alone had 13% fewer hospital contacts (0.87, 0.77-0.99), patients with short education had 16% fewer hospital contacts (<10 years: 0.84, 0.72-0.98) and patients with anxiety symptoms had 27% fewer hospital contacts (0.73, 0.62-0.86) than their counterparts. In contrast, patients with depressive symptoms (0.92, 0.77-1.10) and medium education (10-12 years: 1.05, 0.91-1.22) had the same number of hospital contacts as their counterparts.

CONCLUSIONS

This study indicates that patients with depressive symptoms, short and medium education and patients living alone have a lower long-term use of healthcare contacts following MI than patients without these risk factors. Patients with depressive symptoms and low socioeconomic position would be expected to have a higher need of healthcare after MI as they have a poorer prognosis.

The impact of CCR5-Δ32 deletion on C-reactive protein levels and cardiovascular disease: Results from the Danish Blood Donor Study

BACKGROUND AND PURPOSE

The C-C chemokine receptor 5-Δ32 deletion (CCR5-Δ32) has been associated with lower levels of C-reactive protein (CRP), but the effect on cardiovascular diseases is uncertain. This study addresses the impact of CCR5-Δ32 on the risk of low-grade inflammation and hospitalization with cardiovascular diseases in a large cohort of blood donors.

METHODS

Genotyping of 15,206 healthy participants from The Danish Blood Donor Study for CCR5-Δ32 was performed and combined with CRP measurements and questionnaire data. Cardiovascular disease diagnoses were identified by ICD-10 codes in the Danish National Patient Registry.

RESULTS

CCR5-Δ32-carriers had a higher risk of hospitalization for cardiovascular diseases when compared with wild-type homozygotes (hazard ratio = 1.35, 95%-confidence interval: 1.00-1.87). CRP levels were unaffected by the CCR5-Δ32 deletion.

CONCLUSION

In this cohort, carriers of the CCR5-Δ32 deletion had normal CRP levels but a borderline significant increased risk of cardiovascular diseases.

Developments in the invasive diagnostic-therapeutic cascade of women and men with acute coronary syndromes from 2005 to 2011: a nationwide cohort study

OBJECTIVES

To investigate for trends in sex-related differences in the invasive diagnostic-therapeutic cascade in a population of patients with acute coronary syndromes (ACS).

DESIGN

A nationwide cohort study.

SETTING

Administrative and clinical registries covering all hospitalisations, invasive cardiac procedures and deaths in the Danish population of 5.6 million inhabitants.

PARTICIPANTS

We included 52,565 patients aged 30-90 years who were hospitalised with a first ACS from January 2005 to November 2011. Follow-up was 60 days from the day of index admission.

MAIN OUTCOME MEASURES

Diagnostic coronary angiography, percutaneous coronary intervention or coronary artery bypass within 60 days of index admission.

RESULTS

Women constituted 36%, were older, had more comorbidity and were less likely to be admitted to a hospital with cardiac catheterisation facilities than men. Mortality rates were similar for both sexes. Diagnostic coronary angiography was performed less frequently on women compared with men, both within 1 day (31% vs 42%; p<0.001) and within 60 days (67% vs 80%; p<0.001), yielding adjusted female-male HRs of 0.83 (0.79-0.87) and 0.86 (0.84-0.89), respectively.Among the 39,677 patients undergoing coronary angiography, non-obstructive coronary artery disease was more frequent among women than men (22% vs 9%; p<0.001). Women were less likely to undergo percutaneous coronary intervention (58% vs 72%; p<0.001) and coronary artery bypass (6% vs 11%, p<0.001) within 60 days than men, yielding adjusted HRs of 0.96 (0.92-0.99) and 0.81 (0.74-0.89), respectively. The sex-related differences were not attenuated over time for any of the invasive cardiac procedures (p values for trend >0.05).

CONCLUSIONS

In this nationwide study, men were more likely to undergo an invasive approach than women when hospitalised with a first ACS--a difference persisting from 2005 to 2011. Future studies should focus on the potential mechanisms behind this differential treatment.

Nationwide trends in use and timeliness of diagnostic coronary angiography in acute coronary syndromes from 2005 to 2011: Does distance to invasive heart centres matter?

AIMS

To examine trends in the use of diagnostic coronary angiography according to distance from home to the nearest invasive heart centre following implementation of fast-track protocols and extensive pre-hospital triaging of acute coronary syndrome patients.

METHODS AND RESULTS

We performed a register-based cohort study of all patients admitted to Danish hospitals with incident acute coronary syndrome in 2005-2011. Diagnostic coronary angiography within 60 days of admission was investigated according to distance tertiles (DTs) calculated as range from each patient's home to the nearest invasive heart centre (short DT: <22 km, medium DT: 22-65 km, long DT: >65 km). Cox proportional hazards models were applied.Among the 52,409 patients included, diagnostic coronary angiography was increasingly used during 2005-2011 (short DT: 76% to 81%; medium DT: 74% to 81%; long DT: 69% to 78%; all p-values for trend <0.001). Using the short DT as reference the adjusted hazard ratios for medium DT were 0.87 (0.84-0.89) for 2005-2007, 0.94 (0.90-0.98) for 2008-2009 and 0.94 (0.90-0.98) for 2010-2011. Corresponding figures for long DT were 0.74 (0.72-0.76) for 2005-2007, 0.87 (0.83-0.90) for 2008-2009 and 0.94 (0.90-0.98) for 2010-2011. Length of hospital stay, time to coronary angiography, and 60-day mortality decreased in all DT.

CONCLUSIONS

This nationwide study found significant increases in diagnostic coronary angiography use over time in incident acute coronary syndrome patients with a relatively larger increase in patients residing farthest from an invasive heart centre. Additionally, selected quality of care measures improved in the entire cohort, suggesting a benefit of national clinical protocols.

Effectiveness and safety of different duration of thromboprophylaxis in 16,865 hip replacement patients--a real-word, prospective observational study

INTRODUCTION

Clinical trials have provided evidence about efficacy and safety of extended thromboprophylaxis among total hip replacement (THR) patients. There is a lack of evidence on effectiveness and safety of extended treatment in unselected patients from routine clinical practice. We examined the effectiveness and safety of short (1-6 days) and standard (7-27 days) compared with extended (≥28 days) thromboprophylaxis using population-based design.

MATERIAL AND METHODS

Among all primary THR procedures performed in Denmark from 2010 through 2012 (n=16,865), we calculated adjusted hazard ratios (aHRs) with 95% confidence intervals (CIs) for risk of symptomatic venous thromboembolism (VTE) and major bleeding, in addition to net clinical benefit, defined as the number of VTE avoided minus the number of excess bleeding events occurring among patients prescribed short-term and standard versus extended treatment.

RESULTS

The 90-day risks of VTE were 1.1% (short), 1.4% (standard), and 1.0% (extended), yielding aHRs of 0.83 (95% CI: 0.52-1.31) and 0.82 (95% CI: 0.50-1.33) for short and standard versus extended treatment. The risk of major bleeding was 1.1% (short), 1.0% (standard), and 0.7% (extended), resulting in aHRs of 1.64 (95% CI: 0.83-3.21) and 1.24 (95%CI: 0.61-2.51) for short and standard versus extended thromboprophylaxis. Direct comparison between benefits and harms using net clinical benefit analyses did not favor any of the three treatment durations. The same results were found for VTE or death.

CONCLUSIONS

In a real-word observational cohort of unselected THR patients, we observed no difference in the risks of symptomatic VTE, VTE/ death or bleeding with respect to thromboprophylaxis duration.

Does the association between broken partnership and first time myocardial infarction vary with time after break-up?

BACKGROUND

Marriage is associated with lower risk of coronary heart disease, but it is unknown if the association depends on time since break-up with a partner. In this study we included both married and unmarried couples to study if the association between broken partnership (BP) and first time incident myocardial infarction (MI) changes with time since BP.

METHODS

Register study of the entire Danish population: the population was restricted to those aged 30 to 65 years with follow-up for incident MI between 1985 and 2006 with an annual record on each individual; in total 43 million records. The register data were used to identify MI events. Poisson regression was used to study associations between time since BP and MI adjusted for socio-demographic confounders and hospital admissions. Analyses were stratified by sex.

RESULTS

Compared with unexposed (no BP), the incidence rate ratio (IRR) of MI in men with BP in the same year was 0.97 [95% confidence interval (CI) 0.90-1.05], year before BP was 1.25 (95% CI 1.17-1.34), 2-3 years after BP was 1.12 (95% CI 1.06-1.18), 4-8 years after BP was 1.09 (95% CI 1.05-1.14) and 9+ years since BP was 1.09 (95% CI 1.05-1.12). In women, the IRR same year as BP was 1.45 (95% CI 1.26-1.66), the year after BP was 1.30 (95% CI 1.14-1.50), 2-3 years after BP was 1.26 (95% CI 1.13-1.39), 4-8 years after BP was 1.17 (95% CI 1.08-1.26) and 9+ years since BP was 1.24 (95% CI 1.17-1.32).

CONCLUSIONS

We found both a short-term elevated risk of first time MI following BP and a weaker long-term elevated risk, in both men and women.

The educational gradient in coronary heart disease: the association with cognition in a cohort of 57,279 male conscripts

BACKGROUND

Independently of cardiovascular disease (CVD) risk factors, cognitive ability may account for some of the excess risk of coronary heart disease (CHD) associated with lower education. We aimed to assess how late adolescence cognitive ability and midlife CVD risk factors are associated with the educational gradient in CHD in Norway.

METHODS

In a cohort of 57 279 men born during 1949-1959, health survey information was linked to military conscription records of cognitive ability, to national educational data, to hospitalisation records from the Cardiovascular Disease in Norway (CVDNOR) project and to the Norwegian Cause of Death Registry.

RESULTS

Age and period adjusted HR for incident CHD events was 3.62 (95% CI 2.50 to 5.24) for basic relative to tertiary education, and was attenuated after adjustment; to 2.86 (1.87 to 4.38) for cognitive ability, to 1.90 (1.30 to 2.78) for CVD risk factors, and to 1.84 (1.20 to 2.83) when adjusting for both. Age and period adjusted absolute rate difference was 51 (33 to 70) incident CHD events per 100,000 person years between basic and tertiary educated, and was attenuated after adjustment; to 42 (22 to 61) for cognitive ability, to 25 (7 to 42) for CVD risk factors, and to 24 (5 to 43) when adjusting for both.

CONCLUSIONS

Late adolescence cognitive ability attenuated the educational gradient in incident CHD events. CVD risk factors further attenuated the gradient, and to the same extent regardless of whether cognitive ability was included or not. Cognitive ability might be linked to the educational gradient through CVD risk factors.

Venous thrombosis and risk of cancer in patients with arterial cardiovascular disease

INTRODUCTION

Patients with acute myocardial infarction or stroke are at high risk of venous thromboembolism, which is traditionally considered a complication rather than a marker of occult cancer. We examined the association between venous thromboembolism and cancer in patients with acute myocardial infarction or stroke.

METHODS

We used medical databases to conduct a population-based cohort study including all patients with a first-time venous thromboembolism from 1978 through 2011 who also had a diagnosis of acute myocardial infarction (n=2,878) or stroke (n=1,971) recorded on the same day or within the previous 90days. We followed patients until a first-time cancer diagnosis, emigration, death, or December 31, 2011, whichever came first. We computed 1-year absolute risks and standardised incidence ratios for cancer based on national incidence rates.

RESULTS

The 1-year absolute cancer risk was 2.7% in the acute myocardial infarction cohort and 3.7% in the stroke cohort. The corresponding standardised incidence ratios were 3.22 (95% confidence interval [CI]: 2.54-4.03) and 3.76 (95% CI: 2.95-4.74), respectively. For cancers diagnosed in the first year, the estimated number of venous thromboembolism patients needed to examine to detect one excess cancer was 25 in the acute myocardial infarction cohort and 19 in the stroke cohort.

CONCLUSION

Among acute myocardial infarction and stroke patients, venous thromboembolism can be a marker of occult cancer. We suggest that current guidelines for cancer screening in patients with unprovoked venous thromboembolism could be applied to this group of patients.

Oral anticoagulation therapy after radiofrequency ablation of atrial fibrillation and the risk of thromboembolism and serious bleeding: long-term follow-up in nationwide cohort of Denmark

AIM

To investigate the long-term risk of thromboembolism and serious bleeding associated with oral anticoagulation (OAC) therapy beyond 3 months after radiofrequency ablation (RFA) of atrial fibrillation (AF).

METHODS AND RESULTS

Linking Danish administrative registries, 4050 patients undergoing first-time RFA (2000-11) were identified. Risk of thromboembolism and serious bleeding according to OAC therapy were analysed by incidence rates (presented per 100 person-years) and Cox proportional-hazard models. The median age was 59.5 years (interquartile range, IQR: 52.8-65.2); 26.5% were females. During a median follow-up of 3.4 years (IQR: 2.0-5.6), 71 (1.8%) thromboembolism cases were identified, where incidence rates with and without OAC were 0.56 (0.40-0.78)95%CI and 0.64 (0.46-0.89)95%CI, respectively. Oral anticoagulation discontinuation remained insignificant [hazard ratio 1.42(0.86-2.35)95%CI] in multivariable analysis. Beyond 3 months after RFA 87 (2.1%) serious bleedings occurred; incidence rates with and without OAC were 0.99 (0.77-1.27)95%CI and 0.44 (0.29-0.65)95%CI, respectively. Oral anticoagulation therapy was significantly associated with serious bleeding risk [hazard ratio 2.05(1.25-3.35)95%CI]. In an age- and gender-matched cohort (1 : 4) of 15 848 non-ablated AF patients receiving rhythm-control therapy, thromboembolic rates with and without OAC were 1.34 (1.21-1.49)95%CI and 2.14 (1.98-2.30)95%CI, respectively. Adjusted incidence rate ratio was 0.53 (0.43-0.65)95%CI favouring RFA cohort.

CONCLUSION

Thromboembolic risk beyond 3 months after RFA was relatively low compared with a matched non-ablated AF cohort. With cautious interpretation due to low number of events, serious bleeding risk associated with OAC seems to outweigh the benefits of thromboembolic risk reduction. Randomized studies are warranted to test our results.

Post-myocardial infarction anxiety or depressive symptoms and risk of new cardiovascular events or death: a population-based longitudinal study

OBJECTIVE

To examine the association between anxiety symptoms 3 months after myocardial infarction (MI) and/or new cardiovascular events and death, taking into account established risk factors, and to compare the results with those of the impact of depressive symptoms. Post-MI anxiety symptoms have been associated with a composite outcome of new cardiovascular events or death, but previous studies have not fully adjusted for potential confounders. It remains unclear whether anxiety symptoms are independently associated with both new cardiovascular events and death.

METHODS

A population-based cohort study of 896 persons (70% of eligible) with first-time MI between 1 January 2009 and 31 December 2009, completing the Hospital Anxiety and Depression Scale, were followed up until 31 July 2012.

RESULTS

A total of 239 new cardiovascular events and 94 deaths occurred during 1975 person-years of follow-up. Cox proportional hazards models showed that anxiety symptoms were associated with both new cardiovascular events and death in analysis adjusted for age only. The estimates decreased when adjusted for dyspnea score, physical activity, and depressive symptoms, and anxiety symptoms were no longer associated with new cardiovascular events (hazard ratio [HR] = 1.02, 95% confidence interval [CI] = 0.98-1.07) or with death (HR = 0.94, 95% CI = 0.88-1.01). In fully adjusted models, depressive symptoms remained associated with death (HR = 1.13, 95% CI = 1.05-1.21), but not with new cardiovascular events (HR = 1.02, 95% CI = 0.99-1.06).

CONCLUSIONS

Post-MI anxiety symptoms were not an independent prognostic risk factor for new cardiovascular events or for death, whereas depressive symptoms were associated with an increased risk of mortality.

Citrulline concentration in routinely collected neonatal dried blood spots cannot be used to predict necrotising enterocolitis

AIM

Low citrulline concentration is a marker of low functional enterocyte mass, which may predispose neonates to necrotising enterocolitis (NEC). We hypothesised that citrulline could be used to assess the NEC risk that could not be accounted for by gestational age and birthweight. This study investigated whether citrulline concentrations routinely measured in neonatal dried blood spots (DBS) could predict NEC.

METHODS

We used national Danish registries to retrospectively identify all 361 babies born between 2003 and 2009 who were diagnosed with NEC and had a valid citrulline concentration measured from a DBS sample. The control group comprised 1083 healthy newborns, with three controls for every newborn with NEC, matched for birthweight and gestational age.

RESULTS

Neonatal dried blood spots were collected between 2 and 21 days of life, with a median of 8 days. The results showed that NEC was not associated with low citrulline concentration, either in a direct comparison between the NEC and control groups or in a multivariate logistic regression (p = 0.73).

CONCLUSION

The findings of this study show that the citrulline concentrations found in routine DBS samples between 2003 and 2009 did not predict NEC in newborn babies.

Association of cholesteryl ester transfer protein (CETP) gene polymorphism, high density lipoprotein cholesterol and risk of coronary artery disease: a meta-analysis using a Mendelian randomization approach

BACKGROUND

Recent randomized controlled trials have challenged the concept that increased high density lipoprotein cholesterol (HDL-C) levels are associated with coronary artery disease (CAD) risk reduction. The causal role of HDL-C in the development of atherosclerosis remains unclear. To increase precision and to minimize residual confounding, we exploited the cholesteryl ester transfer protein (CETP)-TaqIB polymorphism as an instrument based on Mendelian randomization.

METHODS

The Mendelian randomization analysis was performed by two steps. First, we conducted a meta-analysis of 47 studies, including 23,928 cases and 27,068 controls, to quantify the relationship between the TaqIB polymorphism and the CAD risk. Next, the association between the TaqIB polymorphism and HDL-C was assessed among 5,929 Caucasians. We further employed Mendelian randomization to evaluate the causal effect of HDL-C on CAD based on the findings from the meta-analysis.

RESULTS

The overall comparison of the B2 allele with the B1 allele yielded a significant risk reduction of CAD (P < 0.0001; OR = 0.88; 95% CI: 0.84-0.92) with substantial between-study heterogeneity (I² = 55.2%; P(heterogeneity) <0.0001). The result was not materially changed after excluding the Hardy-Weinberg Equilibrium (HWE)-violation studies. Compared with B1B1 homozygotes, Caucasian carriers of the B2 allele had a 0.25 mmol/L increase in HDL-C level (95% CI: 0.20-0.31; P <0.0001; I² = 0; P(heterogeneity) =0.87). However, a 1 standard deviation (SD) elevation in HDL-C levels due to the TaqIB polymorphism, was marginal associated with CAD risk (OR =0.79; 95% CI: 0.54-1.03; P =0.08).

CONCLUSIONS

Taken together, our results lend support to the concept that increased HDL-C cannot be translated into a reduction in CAD risk.

Three-year risk of cardiovascular disease among intensive care patients with acute kidney injury: a population-based cohort study

Introduction

Acute kidney injury (AKI) is common among intensive care unit (ICU) patients, but follow-up data on subsequent risk of cardiovascular disease remain sparse. We examined the impact of AKI on three-year risk of first-time heart failure, myocardial infarction (MI), and stroke among ICU patients surviving to hospital discharge, and whether this risk is modified by renal recovery before hospital discharge.

Methods

We used population-based medical registries to identify all adult patients admitted to an ICU in Northern Denmark between 2005 and 2010 who survived to hospital discharge and who had no previous or concurrent diagnosis of heart failure, MI, or stroke. AKI was defined according to the creatinine criteria in the Kidney Disease Improving Global Outcomes classification. We computed the three-year cumulative risk of hospitalization with heart failure, MI, and stroke for patients with and without AKI and the hazard ratios (HRs), using a Cox model adjusted for potential confounders.

Results

Among 21,556 ICU patients surviving to hospital discharge, 4,792 (22.2%) had an AKI episode. Three-year cumulative risk of heart failure was 2.2% in patients without AKI, 5.0% for AKI stage 1, and 5.0% for stages 2 to 3. The corresponding adjusted HRs were 1.33 (95% confidence interval (CI), 1.06 to 1.66) for patients with AKI stage 1 and 1.45 (95% CI, 1.14 to 1.84) for AKI stages 2 to 3, compared to patients without AKI. The three-year cumulative MI risk was 1.0% for patients without AKI, 1.8% for patients with AKI stage 1 and 2.3% for patients with AKI stages 2 to 3. The adjusted HR for MI was 1.04 (95% CI, 0.71 to 1.51) for patients with AKI stage 1 and 1.51 (95% CI, 1.05 to 2.18) for patients with AKI stages 2 to 3, compared with patients without AKI. We found no association between AKI and stroke. The increased risk of heart failure and MI persisted in patients with renal recovery before discharge, although it was less pronounced than in patients without renal recovery.

Conclusions

ICU patients surviving any stage of AKI are at increased three-year risk of heart failure, but not stroke. Only AKI stages 2 to 3 are associated with increased MI risk.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-014-0492-2) contains supplementary material, which is available to authorized users.

Noncardiac surgery in patients with aortic stenosis: a contemporary study on outcomes in a matched sample from the Danish health care system

BACKGROUND

Past research has identified aortic stenosis (AS) as a major risk factor for adverse outcomes in noncardiac surgery; however, more contemporary studies have questioned the grave prognosis. To further our understanding of this, the risks of a 30-day major adverse cardiovascular event (MACE) and all-cause mortality were investigated in a contemporary Danish cohort.

HYPOTHESIS

AS is not an independent risk factor for adverse outcomes in noncardiac surgery.

METHODS

All patients with and without diagnosed AS who underwent noncardiac surgery in 2005 to 2011 were identified through nationwide administrative registers. AS patients (n = 2823; mean age, 75.5 years, 53% female) were matched with patients without AS (n = 2823) on propensity score for AS and surgery type.

RESULTS

In elective surgery, MACE (ie, nonfatal myocardial infarction, ischemic stroke, or cardiovascular death) occurred in 66/1772 (3.7%) of patients with AS and 52/1772 (2.9%) of controls (P = 0.19), whereas mortality occurred in 67/1772 (3.8%) AS patients and 51/1772 (2.9%) controls (P = 0.13). In emergency surgery, 163/1051 (15.5%) AS patients and 120/1051 (11.4%) controls had a MACE (P = 0.006), whereas 225/1051 (21.4%) vs 179/1051 (17.0%) AS patients and controls died, respectively (P = 0.01). Event rates were higher for those with symptoms (defined as use of nitrates, congestive heart failure, or use of loop diuretics), compared with those without symptoms (P < 0.0001).

CONCLUSIONS

AS is associated with high perioperative rates of MACE and mortality, but perhaps prognosis is, in practice, not much worse for patients with AS than for matched controls. Symptomatic patients and patients undergoing emergency surgery are at considerable risks of a MACE and mortality.

Impact of co-morbidity on the risk of first-time myocardial infarction, stroke, or death after single-photon emission computed tomography myocardial perfusion imaging

The impact of co-morbidity on the cardiovascular risk after single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI) remains unclear. We examined the association between a normal versus abnormal SPECT MPI scan on 10-year risk of myocardial infarction, stroke, and all-cause death, overall and according to co-morbidity level. We identified all patients without previous myocardial infarction or cerebrovascular disease, who had an SPECT MPI performed at Aarhus University Hospital Skejby during 1999 to 2011. We categorized the SPECT MPI scan as normal (no defects) or abnormal (reversible and/or fixed defects). Using nationwide medical registries, we obtained information on co-morbidity level (using Charlson co-morbidity index) and outcomes. We used Cox regression to compute hazard ratios with 95% confidence intervals (CIs), adjusting for gender, age, and co-morbidity level. Among 7,040 patients, 4,962 (70%) had normal scans and 2,078 (30%) abnormal scans. Patients with a normal versus abnormal scan had a 10-year risk of 5.7% versus 10.9% for myocardial infarction, 6.0% versus 7.8% for stroke, and 16.5% versus 29.0% for all-cause death. After adjustment, an abnormal scan was associated with increased risk of myocardial infarction (adjusted hazard ratio 1.73, 95% CI 1.37 to 2.18) and all-cause death (1.42, 95% CI 1.23 to 1.65) but not stroke (1.12, 95% CI 0.86 to 1.45). Co-morbidity level did not affect substantially the association between the scan result and the outcomes. In conclusion, independently of co-morbidity level, an abnormal SPECT MPI scan was associated with an increased 10-year risk of myocardial infarction and all-cause death but not stroke.

Agreement between public register and adjudication committee outcome in a cardiovascular randomized clinical trial

The objective of this study is to describe the agreement between randomized trial outcome assessment by committee and outcomes entirely identified through public registers.

METHODS

In the CLARICOR trial, 4,372 patients with stable coronary heart disease received a short course of clarithromycin versus placebo and were followed up for 2.6 years. The pertinent hospital records and death certificates had originally been evaluated by the adjudication committee using common definitions of outcomes mapped into a 6-category list. We now mechanically converted the International Classification of Diseases-coded diagnoses of the public registries into the same categories. After cross-tabulation of the committee diagnoses with National Patient Register diagnoses and Register of Causes of Death, we calculate agreement and compare the estimated intervention effects of the 2 data sets.

RESULTS

With public register data, the protocol-specified categories were slightly more frequent. Overall agreement was 74% for hospital discharges and 60% for cause of death, but the intervention effect, expressed as a hazard ratio, stayed within 4% of the value originally obtained with the adjudication committee (P ≥ .35).

CONCLUSIONS

Our results show a modest agreement between formal adjudication and outcomes deducible from public registers. However, the estimated intervention effect did not differ noticeably between the 2 data sources. If studies on a wide range of public registers confirm these findings, register outcomes may be considered as a replacement for adjudication committees.

Myocardial ischemic events in 'real world' patients with atrial fibrillation treated with dabigatran or warfarin

BACKGROUND

Dabigatran may provide less protection against myocardial infarction than vitamin K antagonists (VKAs) in patients with atrial fibrillation. This may be particularly evident among "switchers" to dabigatran from VKA, as a result of discontinuation effects.

METHODS AND RESULTS

We identified in nationwide Danish registries a cohort of VKA-naïve "new starters" on dabigatran (110 mg twice daily [bid] and 150 mg bid dose regimes) or warfarin, and a cohort of prior VKA-experienced "switchers" to dabigatran or "continuers" on warfarin. Cohorts were followed for an average of 16.0 months. Adjusted Cox regression models were used to compare event rates. Relative to warfarin, there was a nonsignificant trend to lower myocardial infarction rates with dabigatran among VKA-naïve users (110 mg hazard ratio [HR] 0.71; 95% confidence interval [CI], 0.47-1.07; 150 mg HR 0.94; 95% CI, 0.62-1.41); however, there was a nonsignificant trend to increased myocardial infarction rates among prior VKA-experienced users (110 mg HR 1.45; 95% CI, 0.98-2.15; 150 mg HR 1.30; 95% CI 0.84-2.01). An increased myocardial infarction rate relative to warfarin among prior VKA-experienced users was clearly significant during the early follow-up period of <60 days (110 mg HR 3.01; 95% CI, 1.48-6.10; 150 mg HR 2.97; 95% CI, 1.31-6.73). Comparable results were obtained for a composite end point (myocardial infarction, unstable angina, or cardiac arrest) among both VKA-naïve and prior VKA-experienced users.

CONCLUSIONS

In this large-scale nationwide cohort study, we found that switching to dabigatran increased the risk of myocardial infarction compared with continued warfarin usage in the early period after switching. Caution may be warranted, especially when switching prior VKA-experienced patients with atrial fibrillation to dabigatran.

Risk for Myocardial Infarction and Stroke After Community-Acquired Bacteremia

Background—

Infections may trigger acute cardiovascular events, but the risk after community-acquired bacteremia is unknown. We assessed the risk for acute myocardial infarction and ischemic stroke within 1 year of community-acquired bacteremia.

Methods and Results—

This population-based cohort study was conducted in Northern Denmark. We included 4389 hospitalized medical patients with positive blood cultures obtained on the day of admission. Patients hospitalized with bacteremia were matched with up to 10 general population controls and up to 5 acutely admitted nonbacteremic controls, matched on age, sex, and calendar time. All incident events of myocardial infarction and stroke during the following 365 days were ascertained from population-based healthcare databases. Multivariable regression analyses were used to assess relative risks with 95% confidence intervals (CIs) for myocardial infarction and stroke among bacteremia patients and their controls. The risk for myocardial infarction or stroke was greatly increased within 30 days of community-acquired bacteremia: 3.6% versus 0.2% among population controls (adjusted relative risk, 20.86; 95% CI, 15.38–28.29) and 1.7% among hospitalized controls (adjusted relative risk, 2.18; 95% CI, 1.80–2.65). The risks for myocardial infarction or stroke remained modestly increased from 31 to 180 days after bacteremia in comparison with population controls (adjusted hazard ratio, 1.64; 95% CI, 1.18–2.27), but not versus hospitalized controls (adjusted hazard ratio, 0.95; 95% CI, 0.69–1.32). No differences in cardiovascular risk were seen after >6 months. Increased 30-day risks were consistently found for a variety of etiologic agents and infectious foci.

Conclusions—

Community-acquired bacteremia is associated with increased short-term risk of myocardial infarction and stroke.

Total sitting time and risk of myocardial infarction, coronary heart disease and all-cause mortality in a prospective cohort of Danish adults

BACKGROUND

Evidence suggests that sitting time is adversely associated with health risks. However, previous epidemiological studies have mainly addressed mortality whereas little is known of the risk of coronary heart disease. This study aimed to investigate total sitting time and risk of myocardial infarction, coronary heart disease incidence and all-cause mortality.

METHODS

In the Danish Health Examination Survey (DANHES) conducted in 2007-2008 we tested the hypothesis that a higher amount of daily total sitting time is associated with greater risk of myocardial infarction, coronary heart disease and all-cause mortality. The study population consisted of 71,363 men and women aged 18-99 years without coronary heart disease. Participants were followed for myocardial infarction, coronary heart disease and mortality in national registers to August 10, 2012. Cox regression analyses were performed with adjustment for potential confounders and multiple imputation for missing values.

RESULTS

During a mean follow-up period of 5.4 years 358 incident cases of myocardial infarction, 1,446 of coronary heart disease, and 1,074 deaths from all causes were registered. The hazard ratios associated with 10 or more hours of daily sitting compared to less than 6 hours were 1.38 (95% CI: 1.01, 1.88) for myocardial infarction, 1.07 (95% CI: 0.91, 1.27) for coronary heart disease and 1.31 (95% CI: 1.09, 1.57). Compared to sitting less than 6 hours per day and being physically active in leisure time, the hazard ratios of sitting more than 10 hours per day and also being physically inactive in leisure time were 1.80 (95% CI: 1.15, 2.82) for myocardial infarction, 1.42 (95% CI: 1.11, 1.81) for coronary heart disease, and 2.29 (95% CI: 1.82, 2.89) for all-cause mortality.

CONCLUSIONS

The results suggest that a higher amount of daily total sitting time is associated with all-cause mortality, particularly among inactive adults. In relation to coronary heart, disease results were less clear. This paper adds new evidence to the limited data on the evidence of sitting time and cardiovascular disease and mortality.

Heterogeneous effect of two selectin gene polymorphisms on coronary artery disease risk: a meta-analysis

Background

The selectins play important roles in the inflammatory process of coronary artery disease (CAD) and myocardial infarction (MI). Previous studies have shown ambiguous findings regarding a possible association between the selectin genes and CAD. The E-selectin Ser128Arg polymorphism and the P-selectin Thr715Pro polymorphism have been investigated widely but with inconsistent results. We performed a comprehensive meta-analysis to shed light on this issue.

Methods

Data were extracted by searches of MEDLINE, Embase, CNKI, Wanfang, Google Scholar, PORTA, GeNii, CiNii, J-STAGE, Nurimedia and Koreanstudies Information Service System [Kiss] up to October 2013, in which 10 studies on the Ser128Arg polymorphism with 3369 cases and 2577 controls and 10 studies on the Thr715Pro polymorphism with 5886 cases and 18345 controls. A random-effects model was used to calculate the combined odds ratios. The between-study heterogeneity and publication bias were addressed.

Results

The 128Arg carriers had a significant increased risk of CAD (allele comparison: P = 0.02, OR = 1.33, 95%CI 1.04–1.69, P_{heterogeneity} = 0.01); The 715Pro conferred a non-significant risk reduction relative to the 715Thr (allele comparison: P = 0.40, OR = 0.94, 95%CI 0.82–1.08, P_{heterogeneity} = 0.03).Subgroup analyses demonstrated that the 128Arg carriers had a significant increased risk of CAD among Asians (allele comparison: P = 0.001, OR = 2.07, 95%CI 1.33–3.24, P_{heterogeneity} = 0.77) but not among Caucasians (allele comparison: P = 0.33, OR = 1.13, 95%CI 0.88–1.45, P_{heterogeneity} = 0.08). Carrier status for the 715Pro was significantly associated with reduced risk of MI (allele comparison: P = 0.04, OR =  0.81, 95%CI 0.67–0.99, P_{heterogeneity} = 0.14). The asymmetric funnel plot and the Egger's test (P = 0.041) suggested the presence of publication bias for the Ser128Arg polymorphism.

Conclusion

Our results suggested there is an increase in the risk of CAD conferred by the Ser128Arg polymorphism and the thr715Pro polymorphism may be a protective factor of MI.

Impact of gender, co-morbidity and social factors on labour market affiliation after first admission for acute coronary syndrome. A cohort study of Danish patients 2001-2009

Background

Over the last decades survival after acute coronary syndrome (ACS) has improved, leading to an increasing number of patients returning to work, but little is known about factors that may influence their labour market affiliation. This study examines the impact of gender, co-morbidity and socio-economic position on subsequent labour market affiliation and transition between various social services in patients admitted for the first time with ACS.

Methods

From 2001 to 2009 all first-time hospitalisations for ACS were identified in the Danish National Patient Registry (n = 79,714). For this population, data on sick leave, unemployment and retirement were obtained from an administrative register covering all citizens. The 21,926 patients, aged 18–63 years, who had survived 30 days and were part of the workforce at the time of diagnosis were included in the analyses where subsequent transition between the above labour market states was examined using Kaplan-Meier estimates and Cox proportional hazards models.

Findings

A total of 37% of patients were in work 30 days after first ACS diagnosis, while 55% were on sick leave and 8% were unemployed. Seventy-nine per cent returned to work once during follow-up. This probability was highest among males, those below 50 years, living with a partner, the highest educated, with higher occupations, having specific events (NSTEMI, and percutaneous coronary intervention) and with no co-morbidity. During five years follow-up, 43% retired due to disability or voluntary early pension. Female gender, low education, basic occupation, co-morbidity and having a severer event (invasive procedures) and receiving sickness benefits or being unemployed 30 days after admission were associated with increased probability of early retirement.

Conclusion

About half of patients with first-time ACS stay in or return to work shortly after the event. Women, the socially disadvantaged, those with presumed severer events and co-morbidity have lower rates of return.

Trends in time to invasive examination and treatment from 2001 to 2009 in patients admitted first time with non-ST elevation myocardial infarction or unstable angina in Denmark

OBJECTIVE

To investigate trends in time to invasive examination and treatment for patient with first time diagnosis of non-ST elevation myocardial infarction (NSTEMI) and unstable angina during the period from 2001 to 2009 in Denmark.

DESIGN

From 1 January 2001 to 31 December 2009 all first time hospitalisations with NSTEMI and unstable angina were identified in the National Patient Registry (n=65 909). Time from admission to initiation of coronary angiography (CAG), percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) was calculated. We described the development in invasive examination and treatment probability (CAG, PCI and CABG at 3, 7, 10, 30 and 60 days) for the years 2001-2009, taking the competing risk of death into account using Aalen-Johansen estimators and a Fine-Gray model.

SETTING

Nationwide Danish cohort.

RESULTS

The proportion of patients receiving a CAG and PCI increased substantially over time while the proportion receiving a CABG decreased for both NSTEMI and unstable angina. For both NSTEMI and unstable angina, a significant increase in invasive examination and treatment probability at 3 days for CAG and PCI were seen especially from 2007 through to 2009. For NSTEMI, the CAG examination probability at 3 days leaped from 20% in 2007 to 32% in 2008 and 39% in 2009, and for PCI the same was true with a leap in treatment probability from 19% to 28% from 2008 to 2009.

CONCLUSIONS

In Denmark the use of CAG and PCI in treatment of NSTEMI and unstable angina has increased from 2001 to 2009, while the use of CABG has decreased. During the same period, there was a marked increase in invasive examination and treatment probability at 3 days, that is, more patients were treated faster which is in line with the political aim of reducing time to treatment.

The Connexin37 gene C1019T polymorphism and risk of coronary artery disease: a meta-analysis

BACKGROUND AND AIMS

Mounting data have emerged suggesting that the Connexin37 C1019T polymorphism increases susceptibility to coronary artery disease (CAD). However, previous studies yielded conflicting results. In the current study, a comprehensive meta-analysis was performed to investigate whether the C1019T polymorphism is associated with CAD risk.

METHODS

A total of 11 studies examining the C1019T polymorphism and CAD were identified using MEDLINE, Embase, CNKI, Wanfang and CBM, in which 5535 CAD patients and 5626 controls were analyzed. A random-effects model was used to calculate odd ratios and confidence intervals, while addressing between-study heterogeneity. Publication bias was weighed using the Egger's test, Begg-Mazemdar test and funnel plot.

RESULTS

In genetic models with striking heterogeneity, the risk of CAD was not associated with the C1019T polymorphism (allele comparison: p = 0.34, OR = 1.11, 95% CI 0.90-1.36). Stratification by disease endpoints indicated that the 1019T allele was significantly associated with myocardial infarction (MI) (allele comparison: p <0.001, OR = 1.59, 95% CI 1.24-2.03). Further meta-regression analysis indicated that a large proportion of heterogeneity was probably due to the varying proportions of diabetes mellitus (DM) across studies (p = 0.014).

CONCLUSIONS

Our results indicated that the C1019T polymorphism may be a moderate risk factor for MI and that DM was likely a potential source of between-study heterogeneity.

Cognitive test scores in young men and subsequent risk of type 2 diabetes, cardiovascular morbidity, and death

BACKGROUND

The association between cognitive scores in young adulthood and long-term cardiometabolic risks remains unclear.

METHODS

Using population-based registries, we followed 6502 military conscripts from their 22nd birthday until death, emigration, or 55 years of age. We calculated risks and hazard ratios (HRs) associating quartiles of cognitive scores (very high, high, moderate, and low) with type 2 diabetes, hypertension, myocardial infarction, stroke, venous thromboembolism, and death before age 55 years.

RESULTS

The 33-year risk of the combined outcome was inversely associated with cognitive scores (26% for low and 16% for very high scores). Compared with very high scores, the HR for the combined outcome was 1.20 (95% confidence interval = 1.02, 1.41) for high, 1.43 (1.22, 1.68) for moderate, and 1.67 (1.43, 1.95) for low scores. Similar HRs were observed for individual outcomes.

CONCLUSION

Low cognitive score in young adulthood was a strong predictor for type 2 diabetes, cardiovascular morbidity, and death before 55 years of age.