Validity of Peripheral Arterial Disease Diagnoses in the Danish National Patient Registry

Validity of Routinely Reported Rutherford Scores Reported by Clinicians as Part of Daily Clinical Practice

Routinely reported structured data from the electronic health record (EHR) are frequently used for secondary purposes. However, it is unknown how valid routinely reported data are for reuse. This study aimed to assess the validity of routinely reported Rutherford scores by clinicians as an indicator for the validity of structured data in the EHR. This observational study compared clinician-reported Rutherford scores with medical record review Rutherford scores for all visits at the vascular surgery department between April 1, 2016 and December 31, 2018. Free-text fields with clinical information for all visits were extracted for the assignment of the medical record review Rutherford score, after which the agreement with the clinician-reported Rutherford score was assessed using Fleiss' Kappa. A total of 6,633 visits were included for medical record review. Substantial agreement was shown between clinician-reported Rutherford scores and medical record review Rutherford scores for the left ( k  = 0.62, confidence interval [CI]: 0.60-0.63) and right leg ( k  = 0.62, CI: 0.60-0.64). This increased to the almost perfect agreement for left ( k  = 0.84, CI: 0.82-0.86) and right leg ( k  = 0.85, CI: 0.83-0.87), when excluding missing clinician-reported Rutherford scores. Expert's judgment was rarely required to be the deciding factor (11 out of 6,633). Substantial agreement between clinician-reported Rutherford scores and medical record review Rutherford scores was found, which could be an indicator for the validity of routinely reported data. Depending on its purpose, the secondary use of routinely collected Rutherford scores is a viable option.

Adherence and Persistence to Antiplatelet Therapy in Lower Extremity Peripheral Arterial Disease: A Danish Population Based Cohort Study

OBJECTIVE

Adherence to antiplatelet therapy is recommended but unexplored in patients with symptomatic lower extremity peripheral arterial disease (PAD). Therefore, this study aimed to determine adherence and persistence to antiplatelet therapy in patients with PAD, defined as intermittent claudication and chronic limb threatening ischaemia.

DESIGN

Population based nationwide cohort study.

METHODS

This study included all Danish citizens aged ≥ 40 years with a first inpatient or outpatient diagnosis of symptomatic PAD between 2010 - 2017, and who had at least one prescription claim for aspirin and/or clopidogrel within 90 days after diagnosis. Adherence was determined by the proportion of days covered (PDC) during the first year after diagnosis. Persistence was defined as no treatment gap ≥ 30 days between prescription renewals over three year follow up.

RESULTS

A total of 39 687 patients were eligible for inclusion, of whom 23 279 (58.7%) claimed a prescription for aspirin and/or clopidogrel within 90 days of diagnosis. Among these, 12 898 (55.4%) were prevalent users, while the remainder comprised new users who initiated the therapy after the index PAD diagnosis. The mean PDC was 74.5% (SD 35.0%) for prevalent users and 60.5% (SD 30.5%) for new users. Adherence increased with age and number of concomitant drugs. The overall one year cumulative incidence treatment discontinuation was 13.0% (95% CI 12.5 - 13.4%) overall, 17.2% (CI 16.6 - 17.9%) for prevalent users, and 7.9% (CI 7.4 - 8.4%) for new users. At three year follow up, the cumulative incidence of discontinuation was 31.5% (CI 30.9 - 32.2%) overall, 44.6% (CI 43.7 - 45.4%) for prevalent users, and 14.6% (CI 13.9 - 15.3) for new users.

CONCLUSION

Less than 60% of patients with newly diagnosed symptomatic PAD claimed a prescription for antiplatelet therapy within 90 days of diagnosis, and both adherence and persistence were moderate during the first year after diagnosis. These findings underscore the importance of efforts to improve the initiation and continuation of antiplatelet therapy in patients with PAD.

Remnant Cholesterol, Not LDL Cholesterol, Explains Peripheral Artery Disease Risk Conferred by apoB: A Cohort Study

BACKGROUND

Elevated apoB-containing lipoproteins (=remnants+LDLs [low-density lipoproteins]) are a major risk factor for atherosclerotic cardiovascular disease, including peripheral artery disease (PAD) and myocardial infarction. We tested the hypothesis that remnants and LDL both explain part of the increased risk of PAD conferred by elevated apoB-containing lipoproteins. For comparison, we also studied the risk of chronic limb-threatening ischemia and myocardial infarction.

METHODS

apoB, remnant cholesterol, and LDL cholesterol were measured in 93 461 individuals without statin use at baseline from the Copenhagen General Population Study (2003-2015). During up to 15 years of follow-up, 1207 had PAD, 552 had chronic limb-threatening ischemia, and 2022 had myocardial infarction in the Danish National Patient Registry. Remnant and LDL cholesterol were calculated from a standard lipid profile. Remnant and LDL particle counts were additionally measured with nuclear magnetic resonance spectroscopy in 25 347 of the individuals. Results were replicated in 302 167 individuals without statin use from the UK Biobank (2004-2010).

RESULTS

In the Copenhagen General Population Study, multivariable adjusted hazard ratios for risk of PAD per 1 mmol/L (39 mg/dL) increment in remnant and LDL cholesterol were 1.9 (95% CI, 1.5-2.4) and 1.1 (95% CI, 1.0-1.2), respectively; corresponding results in the UK Biobank were 1.7 (95% CI, 1.4-2.1) and 0.9 (95% CI, 0.9-1.0), respectively. In the association from elevated apoB to increased risk of PAD, remnant and LDL cholesterol explained 73% (32%-100%) and 8% (0%-46%), respectively; corresponding results were 63% (30%-100%) and 0% (0%-33%) for risk of chronic limb-threatening ischemia and 41% (27%-55%) and 54% (38%-70%) for risk of myocardial infarction; results for remnant and LDL particle counts corroborated these findings.

CONCLUSIONS

PAD risk conferred by elevated apoB-containing lipoproteins was explained mainly by elevated remnants, while myocardial infarction risk was explained by both elevated remnants and LDL.

External Validation of the OAC3-PAD Bleeding Score in a Nationwide Population of Patients Undergoing Invasive Treatment for Peripheral Arterial Disease

OBJECTIVE

The OAC3-PAD score was developed to predict bleeding risk in patients with lower extremity peripheral arterial disease (PAD), but its performance in concomitant international cohorts is largely unknown. This study aimed to validate the OAC3-PAD score in an unselected nationwide population of patients undergoing invasive treatment for symptomatic PAD.

METHODS

This was a nationwide cohort study including all patients who underwent a first revascularisation procedure or major amputation for symptomatic PAD in Denmark from 2000 - 2021. The study population was stratified based on OAC3-PAD score, and the one year risk of major bleeding was assessed, accounting for the competing risk of death. The score performance was evaluated using calibration plots, C statistic, Brier score, and the index of prediction accuracy (IPA).

RESULTS

A total of 52 016 patients were included (mean age 71 years, 43.8% female). The one year risk of major bleeding increased with higher OAC3-PAD score, ranging from 1.6% (95% confidence interval [CI] 1.4 - 1.8%) to 2.3% (95% CI 2.0 - 2.5%), 3.5% (95% CI 3.2 - 3.8%), and 5.2% (95% CI 4.8 - 5.6%) for patients with low, low moderate, moderate high, and high score, respectively. Using patients with low risk as reference, the OAC3-PAD score effectively categorised patients, demonstrating statistically significant differences in bleeding risk across strata. However, the score showed modest discriminative performance, with a C statistic of 65% (95% CI 63 - 66%) and a Brier score of 2.6% (95% CI 2.5 - 2.7%). Nevertheless, it performed significantly better than the null model, as indicated by an IPA of 3.1%.

CONCLUSION

Among patients who underwent invasive treatment for symptomatic PAD in routine care, the OAC3-PAD score was associated with greater risk of major bleeding with increasing score level. However, its discriminatory ability was modest, and the clinical utility remains to be determined.

Trends in Lower Extremity Artery Disease Repair Incidence, Comorbidity, and Mortality: A Danish Nationwide Cohort Study, 1996-2018

Background

The prevalence of occlusive lower extremity artery disease (LEAD) is rising worldwide while European epidemiology data are scarce. We report incidence and mortality of LEAD repair in Denmark from 1996 through 2018, stratified on open aorto-iliac, open peripheral, and endovascular repair.

Methods

A nationwide cohort study of prospective data from population-based Danish registers covering 1996 to 2018. Comorbidity was assessed by Charlson's Comorbidity Index (CCI). Incidence rate (IR) ratios and mortality rate ratios (MRR) were estimated by multivariable Poisson and Cox regression, respectively.

Results

We identified 41,438 unique patients undergoing 46,236 incident first-time LEAD repairs by either aorto-iliac- (n=5213), peripheral surgery (n=18,665) or percutaneous transluminal angioplasty (PTA, n=22,358). From 1996 to 2018, the age- and sex-standardized IR for primary revascularization declined from 71.8 to 50.2 per 100,000 person-years (IRR, 0.70; 95% CI, 0.66-0.75). Following a 2.5-fold IR increase of PTA from 1996 to 2010, all three repair techniques showed a declining trend after 2010. The declining IR was driven by decreasing LEAD repair due to claudication, and by persons aged below 80 years, while the IR increased in persons aged above 80 years (p interaction<0.001). LEAD repair was more frequent in men (IRRfemale vs male, 0.78; 95% CI, 0.77-0.80), which was consistent over calendar time (p interaction=0.41). Crude mortality decreased following open/surgical repair, and increased following PTA, but all three techniques trended towards lower adjusted mortality comparing the start and the end of the study period (MRRaorto-iliac, 0.71; 95% CI, 0.54-0.93 vs MRRperipheral, 0.76; 95% CI, 0.69-0.83 vs MRRPTA, 0.96; 95% CI, 0.86-1.07). Increasing age and CCI, male sex, smoking, and care dependency associated with increased mortality.

Conclusion

The incidence rate of LEAD repair decreased in Denmark from 1996 to 2018, especially in persons younger than 80 years, and primarily due to reduced revascularization for claudication. Adjusted mortality rates decreased following open surgery, but seemed unaltered following PTA.

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.

Lipoprotein(a) and Risks of Peripheral Artery Disease, Abdominal Aortic Aneurysm, and Major Adverse Limb Events

BACKGROUND

Lp(a) (lipoprotein[a])-lowering therapy to reduce cardiovascular disease is under investigation in phase 3 clinical trials. High Lp(a) may be implicated in peripheral artery disease (PAD), abdominal aortic aneurysms (AAAs), and major adverse limb events (MALE).

OBJECTIVES

The authors investigated the association of high Lp(a) levels and corresponding LPA genotypes with risk of PAD, AAA, and MALE.

METHODS

The authors included 108,146 individuals from the Copenhagen General Population Study. During follow-up, 2,450 developed PAD, and 1,251 AAAs. Risk of MALE was assessed in individuals with PAD at baseline and replicated in the Copenhagen City Heart Study.

RESULTS

Higher Lp(a) was associated with a stepwise increase in risk of PAD and AAA (P for trend <0.001). For individuals with Lp(a) levels ≥99th (≥143 mg/dL, ≥307 nmol/L) vs <50th percentile (≤9 mg/dL, ≤17 nmol/L), multivariable-adjusted HRs were 2.99 (95% CI: 2.09-4.30) for PAD and 2.22 (95% CI: 1.21-4.07) for AAA. For individuals with PAD, the corresponding incidence rate ratio for MALE was 3.04 (95% CI: 1.55-5.98). Per 50 mg/dL (105 nmol/L) genetically higher Lp(a) risk ratios were 1.39 (95% CI: 1.24-1.56) for PAD and 1.21 (95% CI: 1.01-1.44) for AAA, consistent with observational risk ratios of 1.33 (95% CI: 1.24-1.43) and 1.27 (95% CI: 1.15-1.41), respectively. In women smokers aged 70 to 79 years with Lp(a) <50th and ≥99th percentile, absolute 10-year risks of PAD were 8% and 21%, and equivalent risks in men 11% and 29%, respectively. For AAA, corresponding risks were 2% and 4% in women, and 5% and 12% in men.

CONCLUSIONS

High Lp(a) levels increased risk of PAD, AAA, and MALE by 2- to 3-fold in the general population, opening opportunities for prevention given future Lp(a)-lowering therapies.

Elevated remnant cholesterol and atherosclerotic cardiovascular disease in diabetes: a population-based prospective cohort study

AIMS/HYPOTHESIS

Elevated remnant cholesterol is observationally and causally associated with increased risk of atherosclerotic cardiovascular disease (ASCVD) in the general population. This association is not well studied in individuals with diabetes, who are often included in clinical trials of remnant cholesterol-lowering therapy. We tested the hypothesis that elevated remnant cholesterol is associated with increased risk of ASCVD in individuals with diabetes. We also explored the fraction of excess risk conferred by diabetes which can be explained by elevated remnant cholesterol.

METHODS

We included 4569 white Danish individuals with diabetes (58% statin users) nested within the Copenhagen General Population Study (2003-2015). The ASCVDs peripheral artery disease, myocardial infarction and ischaemic stroke were extracted from national Danish health registries without losses to follow-up. Remnant cholesterol was calculated from a standard lipid profile.

RESULTS

During up to 15 years of follow-up, 236 individuals were diagnosed with peripheral artery disease, 234 with myocardial infarction, 226 with ischaemic stroke and 498 with any ASCVD. Multivariable adjusted HR (95% CI) per doubling of remnant cholesterol was 1.6 (1.1, 2.3; p=0.01) for peripheral artery disease, 1.8 (1.2, 2.5; p=0.002) for myocardial infarction, 1.5 (1.0, 2.1; p=0.04) for ischaemic stroke, and 1.6 (1.2, 2.0; p=0.0003) for any ASCVD. Excess risk conferred by diabetes was 2.5-fold for peripheral artery disease, 1.6-fold for myocardial infarction, 1.4-fold for ischaemic stroke and 1.6-fold for any ASCVD. Excess risk explained by elevated remnant cholesterol and low-grade inflammation was 14% and 8% for peripheral artery disease, 26% and 16% for myocardial infarction, 34% and 34% for ischaemic stroke, and 24% and 18% for any ASCVD, respectively. LDL-cholesterol did not explain excess risk, as it was not higher in individuals with diabetes. We also explored the fraction of excess risk conferred by diabetes which can be explained by elevated remnant cholesterol.

CONCLUSIONS/INTERPRETATION

Elevated remnant cholesterol was associated with increased risk of ASCVD in individuals with diabetes. Remnant cholesterol and low-grade inflammation explained substantial excess risk of ASCVD conferred by diabetes. Whether remnant cholesterol should be used as a treatment target remains to be determined in randomised controlled trials.

Epidemiological Trends and Projections of Incidence, Prevalence, and Disease Related Mortality Associated With Peripheral Arterial Disease: Observations Using Nationwide Danish Data

OBJECTIVE

Peripheral arterial disease (PAD) trends remain unclear because contemporary data are sparse and conflicting. This nationwide cohort study quantified changes in PAD incidence, prevalence, and all cause mortality, and projected prevalence development through to 2040.

METHODS

Population based registries covering the entire Danish population aged ≥ 40 years from 2000 to 2018 were linked to assess trends in PAD incidence, prevalence, and all cause mortality, overall and by sex and age groups. Based on observed trends in incidence and mortality, and estimated future annual age distribution and population mortality, the PAD prevalence through to 2040 was projected.

RESULTS

The Danish population aged 40 - 99 years in 2000 - 2018 included 4 811 281 individuals, among whom 145 870 incident PAD diagnoses were identified. The age and sex standardised PAD incidence decreased from 2.26 per 1 000 person years in 2000 to 1.65 in 2018 (incidence RR 0.74, 95% CI 0.72 - 0.77). The incidence was approximately 20% higher in men than women but declined similarly over time. Concurrently, PAD prevalence in the Danish adult population increased from 1.3% to 1.6% (prevalence ratio 1.28, 95% CI 1.26 - 1.30). Among patients aged ≥ 80 years, the prevalence reached 5.7% in women and 7.9% in men. The age and sex standardised annual mortality among patients with PAD decreased from 9.8% in 2000 to 7.2% in 2018 (mortality ratio 0.75, 95% CI 0.72 - 0.78). Projections of PAD prevalence demonstrated that the rising PAD prevalence will continue until around 2030, followed by a decline towards 2040. Among individuals aged ≥ 80 years, the prevalence was projected to plateau at 8.9% for men and 6.2% for women before declining.

CONCLUSION

Within an unselected nationwide population, the incidence and all cause mortality of PAD have declined over the last two decades. Concurrently, prevalence increased and is projected to increase further over the coming decade, emphasising the growing burden of this common atherosclerotic disease in ageing populations.

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.

The use of evidence-based medical therapy in patients with critical limb-threatening ischaemia

AIMS

To describe the practice patterns of evidence-based medical therapy (EBM) and overall mortality in high-risk patients with critical limb-threatening ischaemia (CLTI), compared with patients with myocardial infarction (MI).

METHODS AND RESULTS

Using Danish registries, we identified patients 40-100 years of age with a first-time hospitalization for CLTI or MI from 2008-2018 and grouped them into CLTI, MI, and CLTI and history of MI (CLTI + MI). We examined the likelihood of filling prescriptions with EBM [i.e. antiplatelets (Aps), lipid-lowering agents (LLAs), angiotensin-converting enzyme inhibitor (ACEi), or angiotensin II-receptor blockers (ARBs)] within 3 months after discharge among survivors. Further, we assessed the adjusted 3-year mortality rates. We included 92 845 patients: 14 941 with CLTI (54.7% male), 74 830 with MI (64.6% male) and 3,074 with CLTI + MI (65.2% male). Patients with CLTI and CLTI + MI were older and had more comorbidities than patients with MI. Compared with patients with MI, the unadjusted odds ratios of filling prescriptions were 0.15 [confidence interval (CI): 0.14-0.15] for AP, 0.26 (CI: 0.25-0.27) for LLA, and 0.71 (CI: 0.69-0.74) for ARB/ACEi in patients with CLTI, and 0.22 (CI: 0.20-0.24) for AP, 0.38 (CI: 0.35-0.42) for LLA, and 1.17 (CI: 1.08-1.27) for ARB/ACEi in patients with CLTI + MI. Adjusted analyses showed similar results. Compared with patients with MI, adjusted 3-year hazard ratios for mortality were 1.69 (CI: 1.64-1.74) in patients with CLTI and 1.60 (CI: 1.51-1.69) in patients with CLTI + MI.

CONCLUSION

Patients with CLTI were undertreated with EBM and carried a more adverse prognosis, as compared with patients with MI, despite similar guidelines.

Relevance of the Viborg Population Based Screening Programme (VISP) for Cardiovascular Conditions Among 67 Year Olds: Attendance Rate, Prevalence, and Proportion of Initiated Cardiovascular Medicines Stratified By Sex

OBJECTIVE

To report sex specific overall attendance rate, prevalence of screen detected cardiovascular conditions, proportion of unknown conditions before screening, and proportion initiating prophylactic medicine among 67 year olds in Denmark.

DESIGN

Cross sectional cohort study.

METHODS

Since 2014, all 67 year olds in Viborg, Denmark, have been invited to screening for abdominal aortic aneurysm (AAA), peripheral arterial disease (PAD), carotid plaque (CP), hypertension, cardiac disease, and type 2 diabetes. Individuals with AAA, PAD, and or CP are recommended cardiovascular prophylaxis. Combining data with registries has facilitated estimation of unknown screen detected conditions. Up to August 2019, 5 505 had been invited; registry data were available for the first 4 826 who were invited.

RESULTS

The attendance rate was 83.7%, without sex difference. Screen detected prevalence was significantly lower among women than men: AAA, 5 (0.3%) vs. 38 (1.9%) (p < .001); PAD, 90 (4.5%) vs. 134 (6.6%) (p = .011); CP, 641 (31.8%) vs. 907 (44.8%) (p < .001); arrhythmia, 26 (1.4%) vs. 77 (4.2%) (p < .001); blood pressure ≥ 160/100 mmHg, 277 (13.8%) vs. 346 (17.1%) (p = .004); and HbA1c ≥ 48 mmol/mol, 155 (7.7%) vs. 198 (9.8%) (p = .019), respectively. Pre-screening proportions of unknown conditions were particularly high for AAA (95.4%) and PAD (87.5%). AAA, PAD, and or CP were found in 1 623 (40.2%), of whom 470 (29.0%) received pre-screening antiplatelets and 743 (45.8%) lipid lowering therapy. Furthermore, 413 (25.5%) started antiplatelet therapy and 347 (21.4%) started lipid lowering therapy. Only smoking was significantly associated with all vascular conditions in multivariable analysis: odds ratios (ORs) for current smoking were AAA 8.11 (95% CI 2.27 - 28.97), PAD 5.60 (95% CI 3.61 - 8.67) and CP 3.64 (95% CI 2.95 - 4.47).

CONCLUSION

The attendance rate signals public acceptability for attending cardiovascular screening. Men had more screen detected conditions than women, but prophylactic medicine was started equally frequently in both sexes. Sex specific cost effectiveness follow up is warranted.

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.

Incidence of myocardial infarction, heart failure, and cardiovascular mortality in patients with peripheral artery disease: trends between 1997 and 2016

AIMS

Over the past decades, there have been improvements in the management of cardiovascular (CV) disease and risk factors. Long-term contemporary data on the population-level incidence of myocardial infarction (MI), heart failure (HF), and CV mortality in patients with peripheral artery disease (PAD) are sparse, which we aim to investigate in this study.

METHODS AND RESULTS

Danish nationwide registers were used to identify all patients aged ≥18 years, with first diagnosis of PAD between 1997 and 2016. Age-standardized incidence rates (IRs) per 1000 person-years were calculated to estimate trends of MI, HF, and CV mortality. The risk of MI, HF, and CV mortality was estimated by 1-year cumulative incidence with death as the competing risk. A total of 131 568 patients with PAD were identified [median age 70.67 (interquartile range, IQR, 61-78) years and 53.05% males]. The IRs showed increasing trends of MI until 2002, with an estimated annual percentage change (APC) of + 0.6 [95% confidence interval (CI) 3.3-16.1, P-value 0.2]. After the year 2002, MI incidence persistently decreased until the study end with an estimated APC of -5.0 (95% CI 3.7-6.3, P < 0.0001), HF declined with an estimated APC of -3.3 (95% CI 2.0-4.6, P < 0.0001); and CV mortality declined, with an APC of -3.5 (95% CI 3.0-4.0, P < 0.0001).

CONCLUSION

The incidence of MI (since 2002) and HF in patients with PAD has significantly decreased over time, together with a decline in CV mortality. Our results suggest that preventive strategies have overall improved, most likely due to improvements in the application of guidelines in clinical care.

Vascular endothelial growth factor inhibition in retinal vein occlusion does not associate with cardiovascular morbidity and mortality

PURPOSE

Intravitreal treatment with vascular endothelial growth factor (VEGF) inhibitors have proven safe in clinical trials, but often on selected patient groups and without statistical power to investigate rare safety events. Data on anti-VEGF treatment in retinal vein occlusion (RVO) patients are sparsely represented and studies providing population-based, long-term follow-up are needed to assess the risks in a nationwide setting. We aimed to evaluate the association between treatment with anti-VEGF and risk of incident cardiovascular disease (CVD) and all-cause mortality in patients with RVO, and whether this association was affected by selected risk factors.

DESIGN

Cohort study from January 2012 to December 2018 using Danish nationwide registries linked on an individual level. Subjects, Participants, and/or Controls: RVO patients (n=7235), exposed (n=3508) and unexposed (n=3727) to anti-VEGF, aged 40 years or more, alive and living in Denmark. Methods, Intervention, or Testing: Cox proportional hazards analysis evaluating the effect of intravitreal VEGF inhibitory treatment on incident CVD and all-cause mortality.

MAIN OUTCOME MEASURES

A pre-defined analysis plan specified primary outcomes as hazard ratios (HR) of a composite CVD endpoint and all-cause mortality in patients treated with anti-VEGF compared with untreated. Secondary outcomes included cumulative dose analysis, HRs on subgroups of CVD and stratified analyses evaluating the effect of sex, age, diabetes, intensive treatment, and pre-existing CVD on the HRs.

RESULTS

We found no increased risk of composite CVD (HR 1.07, 95% CI 0.89 to 1.29) or all-cause mortality (HR 0.88, 95% CI 0.77 to 1.00) in RVO patients treated with anti-VEGF. In the secondary analyses we found no dose-response relationship. We found an increased risk of intracranial hemorrhage (HR 1.66, 95% CI 1.02 to 2.71), but no increased risks in remaining subgroups of CVD. We found no increased risk associated with selected pre-disposing risk factors, and no increased risk in patients with pre-existing CVD.

CONCLUSIONS

Treatment with anti-VEGF in RVO patients is safe, when evaluated in a nationwide, population-based setting. An increased risk of intracranial hemorrhage might be present, but cannot be reliably quantified and should be further elucidated by larger population-based studies including all indications for anti-VEGF treatment.

Circulating Biomarkers Predict Symptomatic but Not Asymptomatic Carotid Artery Stenosis

BACKGROUND

Subjects exposed to risk factors such as age, gender, hypertension, diabetes mellitus, and smoking are prone to atherosclerotic events.

AIMS

The main aim of this longitudinal cohort study was to determine whether the role of novel plasma biomarkers for atherosclerotic carotid artery disease is different in subjects developing symptomatic carotid artery stenosis (CAS), as opposed to those with incident asymptomatic CAS.

METHODS

The following biomarkers were measured in 5,550 middle-aged subjects in a population-based cohort study: C-reactive protein (CRP), lipoprotein-associated phospholipase A2 mass and activity, proneurotensin, midregional proadrenomedullin (MR-proADM), midregional proatrial natriuretic peptide (MR-proANP), N-terminal pro-B-type natriuretic peptide (NT pro-BNP), copeptin, and cystatin C. After exclusion of those with prevalent CAS, subjects were thereafter followed in national patient registers for 23.4 (interquartile range 19.5-24.3) years regarding incident symptomatic and asymptomatic CAS.

RESULTS

Among 110 patients with confirmed incident CAS, 56 were symptomatic and 54 were asymptomatic. When including conventional risk markers in a Cox regression analysis, NT pro-BNP (hazard ratio [HR] 1.59; 95% confidence interval [CI]: 1.20-2.11), MR-proADM (HR 1.40; CI: 1.13-1.73), cystatin C (HR 1.21; CI: 1.02-1.43), and CRP (HR 1.53; CI: 1.13-1.73) were independently associated with incident symptomatic CAS, whereas no plasma biomarker was associated with incident asymptomatic CAS.

CONCLUSION

Plasma biomarkers NT pro-BNP, MR-proADM, cystatin C, and CRP were independently associated with incident symptomatic CAS, whereas no such association could be demonstrated with incident asymptomatic CAS. As these biomarkers indicate future development of clinically relevant atherosclerotic CAS, their potential utility in relation to intensified preventive measures and selection of potential candidates for carotid surgery should be further evaluated.

Clinician Specialty, Access to Care, and Outcomes Among Patients with Peripheral Artery Disease

BACKGROUND

Understanding the relationship between patterns of peripheral artery disease and outcomes is an essential step toward improving care and outcomes. We hypothesized that clinician specialty would be associated with occurrence of major adverse vascular events (MAVE).

METHODS

Patients with at least 1 peripheral artery disease-related encounter in our health system and fee-for-service Medicare were divided into groups based on the specialty of the clinician (ie, cardiologist, surgeon, podiatrist, primary care, or other) providing a plurality of peripheral artery disease-coded care in the year prior to index encounter. The primary outcome was MAVE (a composite of all-cause mortality, myocardial infarction, stroke, lower extremity revascularization, and lower extremity amputation).

RESULTS

The cohort included 1768 patients, of whom 30.0% were Black, 23.9% were Medicaid dual-enrollment eligible, and 31.1% lived in rural areas. Patients receiving a plurality of their care from podiatrists had the highest 1-year rates of MAVE (34.4%, P <.001), hospitalization (65.9%, P <.001), and amputations (22.6%, P <.001). Clinician specialty was not associated with outcomes after adjustment. Patients who were Medicaid dual-eligible had higher adjusted risks of mortality (adjusted hazard ratio [HR_adj] 1.54, 95% confidence interval [CI] 1.11-2.14) and all-cause hospitalization (HR_adj 1.20, 95% CI 1.03-1.40) and patients who were Black had a higher adjusted risk of amputation (HR_adj 1.49, 95% CI 1.03-2.15).

CONCLUSIONS

Clinician specialty was not associated with worse outcomes after adjustment, but certain socioeconomic factors were. The effects of clinician specialty and socioeconomic status were likely attenuated by the fact that all patients in this study had health insurance; these analyses require confirmation in a more representative cohort.

Revascularisation for Symptomatic Peripheral Artery Disease: External Applicability of the VOYAGER PAD Trial

OBJECTIVE

In the VOYAGER PAD trial, rivaroxaban 2.5 mg plus aspirin significantly reduced the primary composite efficacy outcome of acute limb ischaemia, major amputation, myocardial infarction, ischaemic stroke, or cardiovascular death compared with aspirin alone. However, patients enrolled in the trial may not reflect patients encountered in daily clinical practice. This study described the proportion of patients eligible for VOYAGER PAD within the nationwide Danish Vascular Registry (DVR), reasons for ineligibility, and outcomes according to eligibility.

METHODS

In total, 32 911 patients who underwent lower extremity revascularisation for symptomatic peripheral arterial disease (PAD) in the DVR (2000-2016) were identified. Trial inclusion and exclusion criteria were applied, and the three year cumulative incidence of primary and secondary trial outcomes was estimated.

RESULTS

Altogether, 27.1% of patients with PAD in the DVR were "VOYAGER eligible". Of those not included, 30.7% had at least one exclusion criterion ("VOYAGER excluded"), and an additional 42.3% did not fulfil the inclusion criteria ("VOYAGER not included"). The main reasons for exclusion were atrial fibrillation (32.3%), poorly regulated hypertension (20.6%), requirement for long term dual antiplatelet therapy (10.9%), cytochrome P450 inhibitors or inducers (9.7%), and renal failure (9.3%). The three year rate of the primary efficacy outcome was 10.08 per 100 person years among the "VOYAGER eligible", 16.32 among "VOYAGER excluded", and 6.98 among the "VOYAGER not included". For the primary safety outcome of thrombolysis in myocardial infarction (TIMI) major bleeding, rates were 2.24, 3.76, and 1.17, respectively. Rates of secondary endpoints were also consistently lower for patients who did not meet the inclusion criteria (predominantly due to central aorto-iliac procedures) and highest for "VOYAGER excluded" patients. "VOYAGER eligible" patients experienced a higher cumulative incidence of most endpoints than patients enrolled in the control arm of the VOYAGER PAD trial.

CONCLUSION

Among patients in routine clinical practice, 27.1% were eligible for the VOYAGER PAD trial. These patients were older, had more severe vascular symptoms, higher bleeding risk, and worse prognosis than trial participants.

The impact of peripheral artery disease on major adverse cardiovascular events following myocardial infarction

AIMS

Peripheral artery disease (PAD) constitute a high-risk with adverse clinical outcomes. We aimed to investigate the cardiovascular outcomes following myocardial infarction (MI).

METHODS AND RESULTS

This nationwide, Danish register-based follow-up study includes all patients experiencing an MI between 2000 and 2017. Patients with and without PAD were compared. Multivariable logistic regression was used to derive relative risks of 1-year major adverse cardiovascular events (MACE; all-cause mortality, reinfarction, stroke or heart failure). Individual components, cardiovascular mortality, and bleeding, standardized to age, sex and comorbidity distributions of all patients were assessed. MI patients with PAD (n = 5083, 2.9%) were older and more comorbid compared to patients without PAD (n = 174,673). After standardization, PAD was associated with higher 1-year relative risks of MACE (RR 1.21 [95% CI 1.17;1.25]), all-cause (RR 1.29 [95% CI 1.24;1.35]) and cardiovascular mortality (RR 1.3 [95% CI 1.24;1.36]), reinfarction (RR 1.17 [95% CI 1.11;1.22]), stroke (RR 1.12 [95% CI 0.92;1.32]), heart failure (RR 1.22 [95% CI 1.12;1.32]), and bleeding episodes (RR 1.25 [95% CI 1.04,1.46]). Similar results were seen in 30-day survivors after adjustment for antithrombotic post-discharge medication for MACE (RR 1.25 [95% CI 1.20,1.31]), all-cause mortality (RR 1.47 [95% CI 1.37,1.57], cardiovascular mortality (RR 1.49 [95% CI 1.37,1.61]), reinfarction (RR 1.17 [95% CI 1.08,1.12]) and heart failure (RR 1.22 [95% CI 1.12,1.32]).

CONCLUSION

Comparing to patients without PAD, patients with PAD had increased 1-year relative risk of MACE, all-cause mortality, reinfarction, stroke, heart failure, cardiovascular mortality and bleeding following MI. The low prevalence of PAD is suggestive of considerable under-diagnosing.

Elevated remnant cholesterol increases the risk of peripheral artery disease, myocardial infarction, and ischaemic stroke: a cohort-based study

AIMS 

The atherogenic potential of cholesterol in triglyceride-rich lipoproteins, also called remnant cholesterol, is being increasingly acknowledged. Elevated remnant cholesterol is associated with increased risk of myocardial infarction and ischaemic stroke. We tested the hypothesis that elevated remnant cholesterol is also associated with increased risk of peripheral artery disease (PAD).

METHODS AND RESULTS 

We studied 106 937 individuals from the Copenhagen General Population Study recruited in 2003-15. During up to 15 years of follow-up, 1586 were diagnosed with PAD, 2570 with myocardial infarction, and 2762 with ischaemic stroke. We also studied 13 974 individuals from the Copenhagen City Heart Study recruited in 1976-78. During up to 43 years of follow-up, 1033 were diagnosed with PAD, 2236 with myocardial infarction, and 1976 with ischaemic stroke. Remnant cholesterol was calculated from a standard lipid profile. Diagnoses were from Danish nationwide health registries. In the Copenhagen General Population Study, elevated remnant cholesterol levels were associated with higher risk of PAD, up to a multivariable adjusted hazard ratio (HR) of 4.8 (95% confidence interval 3.1-7.5) for individuals with levels ≥1.5 mmol/L (58 mg/dL) vs. <0.5 mmol/L (19 mg/dL). Corresponding results were 4.2 (2.9-6.1) for myocardial infarction and 1.8 (1.4-2.5) for ischaemic stroke. In the Copenhagen City Heart Study, corresponding HRs were 4.9 (2.9-8.5) for PAD, 2.6 (1.8-3.8) for myocardial infarction, and 2.1 (1.5-3.1) for ischaemic stroke.

CONCLUSION 

Elevated remnant cholesterol is associated with a five-fold increased risk of PAD in the general population, higher than for myocardial infarction and ischaemic stroke.

Intake of marine n-3 polyunsaturated fatty acids and the risk of incident peripheral artery disease

BACKGROUND

A high intake of marine n-3 polyunsaturated fatty acids (PUFAs) may lower the risk of coronary heart disease and ischemic stroke. The association between intake of marine n-3 PUFAs and development of peripheral artery disease (PAD), however, remains unexplored. We hypothesised that intake of marine n-3 PUFAs, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and the sum of EPA + DHA was associated with a lower risk of incident PAD.

METHODS

We used data from the Danish Diet, Cancer and Health cohort and investigated the associations between intake of EPA, DHA and EPA + DHA and development of PAD. Information on intake of n-3 PUFAs was obtained through a validated food frequency questionnaire. Potential PAD cases were identified through linkage to the Danish National Patient Register and subsequently, all cases were validated.

RESULTS

Data were available from 55,248 participants and during a median of 13.6 years of follow-up, 950 cases of PAD were identified. Multivariate Cox regression analyses with adjustments for established risk factors showed no statistically significant associations between intake of EPA (p = 0.255), DHA (p = 0.071) or EPA + DHA (p = 0.168) and the rate of incident PAD.

CONCLUSIONS

We did not confirm our hypothesis that intake of EPA, DHA or EPA + DHA was associated with a lower risk of incident PAD.

Agreement Between Self-Reported Information and Administrative Data on Comorbidities, Imaging and Treatment in Denmark - A Validation Study of 38,745 Patients with Knee or Hip Osteoarthritis

Purpose

To validate self-reported information obtained from patients with knee or hip osteoarthritis (OA) in primary care against administrative data from the three national Danish registries.

Patients and Methods

We compared the baseline and 12-month follow-up data from 38,745 patients with knee or hip OA participating in the Good Life with osteoArthritis in Denmark (GLA:D^®) program with registry-based data on joint surgeries, pain medication dispensing, radiographs, and hospital diagnoses. Agreement was calculated using Cohen's Kappa (k) and percentage agreement, both with 95% CI.

Results

There was a moderate agreement between self-report and registry-based data for previous knee surgery (k=0.58, 84.99%) and a substantial agreement for previous hip surgery (k=0.73, 97.05%). Agreement varied from 0.05 to 0.95 and 84.99% to 99.94% for different types of surgeries with lowest agreement for collateral ligament surgery (k=0.05, 99.82%) and highest agreement for joint replacement (k=0.95, 99.54% for knee; k=0.95, 99.48% for hip). There was a moderate agreement (k=0.41, 81.59%) for knee and a slight agreement (k=0.20, 64.79%) for hip radiographs. Agreement varied from 0.01 to 0.53 and 65.39% to 99.90% for pain medication with lowest agreement for topical NSAID (k=0.01, 95.00%) and highest agreement for opioids (k=0.53, 92.56%). For comorbidities, agreement varied from 0.14 to 0.90 and 78.07% to 98.91%, with lowest agreement for anemia or other blood disease (k=0.14, 97.63%) and highest agreement for diabetes (k=0.90, 98.73%).

Conclusion

As the most common types of pain medication used by patients with OA can be bought over-the-counter and as most OA patients are treated in primary care, which is often not covered by national registries, self-report of pain medication use and comorbidities is preferred but cannot be sufficiently validated against registry-based data. Future studies collecting self-reported information on joint surgery and pain medication from patients with OA should use a less detailed categorization to improve accuracy.

The association of healthcare disparities and patient-specific factors on clinical outcomes in peripheral artery disease

BACKGROUND

PAD increases the risk of cardiovascular mortality and limb loss, and disparities in treatment and outcomes have been described. However, the association of patient-specific characteristics with variation in outcomes is less well known.

METHODS

Patients with PAD from Duke University Health System (DUHS) between January 1, 2015 and March 31, 2016 were identified. PAD status was confirmed through ground truth adjudication and predictive modeling using diagnosis codes, procedure codes, and other administrative data. Symptom severity, lower extremity imaging, and ankle-brachial index (ABI) were manually abstracted from the electronic health record (EHR). Data was linked to Centers for Medicare and Medicaid Services data to provide longitudinal follow up. Primary outcome was major adverse vascular events (MAVE), a composite of all-cause mortality, myocardial infarction (MI), stroke, lower extremity revascularization and amputation.

RESULTS

Of 1,768 patients with PAD, 31.6% were asymptomatic, 41.2% had intermittent claudication (IC), and 27.3% had chronic limb-threatening ischemia (CLTI). At 1 year, patients with CLTI had higher rates of MAVE compared with asymptomatic or IC patients. CLTI and Medicaid dual eligibility were independent predictors of mortality. CLTI and Black race were associated with amputation.

CONCLUSIONS

Rates of MAVE were highest in patients with CLTI, but patients with IC or asymptomatic disease also had high rates of adverse events. Black and Medicaid dual-eligible patients were disproportionately present in the CLTI subgroup and were at higher risk of amputation and mortality, respectively. Future studies must focus on early identification of high-risk patient groups to improve outcomes in patients with PAD.

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.

Trends in Use of Cardioprotective Medication in Peripheral Artery Disease: A Nationwide Study

Background

Guideline‐based cardioprotective medical therapy is intended to reduce the burden of adverse cardiovascular and limb outcomes in patients with peripheral artery disease (PAD). However, contemporary data describing trends in use of medication remains limited. The present study, therefore, aims to investigate changes in use of cardioprotective medication in PAD.

Methods and Results

By using Danish national healthcare registries, we identified all patients with first‐time diagnosis of PAD (1997–2016) and classified them into two groups: (1) PAD+ that includes all patients with PAD with a history of cardiovascular disease, ie, myocardial infarction, atrial fibrillation, and stroke (n=162 627); and (2) PAD (n=87 935) that comprise patients without a history of cardiovascular disease. We determined the use of medication in the first 12 months after the incident diagnosis of PAD and estimated age standardized 1‐year mortality rates. Our results showed increase in use of cardioprotective medication throughout the study period in both groups. However, PAD+ had a higher use of medication (acetylsalicylic acid, 3.5%–48.4%; Clopidogrel, 0%–17.6%; vitamin K antagonists, 0.9%–7.8%; new oral anticoagulants, 0.0%–10.1%; Statins, 1.9%–58.1%; angiotensin‐converting enzyme inhibitors, 1.2%–20.6%), compared with PAD (acetylsalicylic acid, 2.9%–54.4%; Clopidogrel, 0%–11.9%; vitamin K antagonists, 0.9%–2.4%; new oral anticoagulants, 0.0%–3.4%; Statins, 1.5%–56.9%; angiotensin‐converting enzyme, 0.9%–17.2%), respectively. Furthermore, 1‐year mortality rates in PAD declined with increased use of medications during study.

Conclusions

In this nationwide study, use of cardioprotective medication increased considerably with time, but compared to patients with other atherosclerotic diseases, there remains an underuse of guideline‐based medical therapy in patients with PAD.

Positive Predictive Value of Diagnostic Codes for Inflammatory Bowel Disease in the Danish National Patient Registry Among Individuals 50+ Years, Using Patient Records as Reference Standard

Purpose

Inflammatory bowel diseases (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC), are chronic diseases. The aim was to validate diagnoses of IBD among patients aged 50+ years in the Danish National Patient Registry (NPR) by comparison with patient medical records.

Patients and Methods

Men and women in the Diet, Cancer and Health (DCH) cohort were linked to NPR, and cases with a diagnosis of IBD and their respective hospital records were identified. Validation was performed by comparing patient medical records with information on discharge diagnoses of IBD from the NPR.

Results

Of 57,053 individuals in the DCH-cohort, 339 were registered with an IBD diagnosis in NPR, with 277 (82%) records available for review. Among 277 patients, the positive predictive values (PPVs) of one CD or UC registration in NPR were 78% for IBD overall, 51% for CD and 54% for UC. One hundred fifty-seven patients had at least two CD and/or UC registrations with PPVs of 90% for IBD overall, 65% for CD and 73% for UC. One hundred and two patients had at least three registrations with PPVs of 97% for IBD overall, 75% for CD and 88% for UC. 96% were diagnosed at a specialized department. Other diagnoses coded as IBD mostly included microscopic colitis, irritable bowel syndrome and cancer.

Conclusion

Validity of IBD diagnoses in the registry of individuals aged 50+ years increased with the number of registrations. It is recommended that these results are taken into consideration in future studies, especially in epidemiology research using NPR as a data source for patients diagnosed with IBD.

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.

Editor's Choice - Regional Versus General Anaesthesia in Peripheral Vascular Surgery: a Propensity Score Matched Nationwide Cohort Study of 17 359 Procedures in Denmark

OBJECTIVE

Cardiopulmonary comorbidity is common in vascular surgery. General anaesthesia (GA) may impair perfusion and induce respiratory depression. Regional anaesthesia (RA), including neuraxial or peripheral nerve blocks, may therefore be associated with a better outcome.

METHODS

This was a nationwide retrospective cohort study. All open inguinal and infra-inguinal arterial surgical reconstructions from 2005 to 2017 were included. Data were extracted from national registries. Multivariable linear and logistic regression models and propensity score matching were used. The propensity score was derived by developing a model that predicted the probability that a given patient would receive GA based on age, comorbidity, anticoagulant medication, procedure type, and the urgency of surgery. Matching was performed in four groups based on American Society of Anesthesiologists' score I - II, score III - V, and gender. Outcome parameters included surgical and general complications (bleeding, thrombosis/embolus, cardiac, pulmonary, renal, cerebral, and >3 days intensive care therapy), length of stay, and 30 day mortality, hypothesising a better outcome after RA.

RESULTS

There were 10 509 procedures in the GA group and 6 850 in the RA group. After propensity score matching, 6 267 procedures were included in each group. Surgical and general complications were significantly more common after GA in both matched (3.8 vs. 2.5%, p < .001 and 6.5 vs. 4.2%, p < .001) and unmatched analyses (3.8 vs. 2.5%, p < .001 and 6.5 vs. 4.2%, p < .001). The 30 day mortality rate was significantly higher after GA, in matched and un matched analyses (3.1 vs. 2.4%, p = .019 and 4.1 vs. 2.4%, p < .001). There was no difference in length of stay.

CONCLUSION

RA may be associated with a better outcome, compared with GA, after open inguinal and infra-inguinal peripheral vascular surgery. In the clinical context when RA is not feasible, GA can still be considered safe.

Higher habitual flavonoid intakes are associated with a lower risk of peripheral artery disease hospitalizations

BACKGROUND

The role of nutrition in the primary prevention of peripheral artery disease (PAD), the third leading cause of atherosclerotic cardiovascular disease, is undetermined. Flavonoids may attenuate atherosclerosis and therefore persons who consume flavonoid-rich foods may have a lower risk of developing PAD.

OBJECTIVES

We aimed to examine the association between flavonoid intake and PAD hospitalizations and investigate if the association differs according to established risk factors for PAD.

METHODS

Baseline data from 55,647 participants of the Danish Diet, Cancer, and Health Study without PAD, recruited from 1993 to 1997, were cross-linked with Danish nationwide registries. Flavonoid intake was calculated from FFQs using the Phenol-Explorer database. Associations were examined using multivariable-adjusted restricted cubic splines based on Cox proportional hazards models.

RESULTS

After a median [IQR] follow-up time of 21 [20-22] y, 2131 participants had been hospitalized for any PAD. The association between total flavonoid intake and total PAD hospitalizations was nonlinear, reaching a plateau at ∼750-1000 mg/d. Compared with the median flavonoid intake in quintile 1 (174 mg/d), an intake of 1000 mg/d was associated with a 32% lower risk of any PAD hospitalization (HR: 0.68; 95% CI: 0.60, 0.77), a 26% lower risk of atherosclerosis (HR: 0.74; 95% CI: 0.62, 0.88), a 28% lower risk of an aneurysm (HR: 0.72; 95% CI: 0.59, 0.88), and a 47% lower risk of a hospitalization for other peripheral vascular disease (HR: 0.53; 95% CI: 0.42, 0.67). A higher total flavonoid intake was also significantly associated with a lower incidence of revascularization or endovascular surgery and lower extremity amputation. The association between total flavonoid intake and PAD hospitalizations differed according to baseline smoking status, alcohol intake, BMI, and diabetes status.

CONCLUSIONS

Ensuring the adequate consumption of flavonoid-rich foods, particularly in subpopulations prone to the development of atherosclerosis, may be a key strategy to lower the risk of PAD.

Time trends in the risk of atrial fibrillation and ischaemic stroke in patients with peripheral artery disease between 1997 and 2015

Objective

The risk of atrial fibrillation (AF) and stroke in patients with peripheral artery disease (PAD) is an important issue that has not been investigated adequately. Our aim with the present study was to explore trends in the incidence of AF and stroke in patients with PAD.

Methods

We employed Danish nationwide registers to identify all patients with first-time diagnosis of PAD (aged ≥18 years) between 1997 and 2015. Age-standardised incidence rates per 1 000 person-years were calculated to estimate trends of AF and stroke. Risk of AF and stroke was estimated by 1 year cumulative incidence.

Results

A total of 121.241 patients with first-time diagnosis of PAD were identified. The 1-year cumulative incidence of AF in patients with PAD were 1.97% for year 1997–2000, 2.63% for year 2001–2005, 2.66% for year 2006–2010 and 2.78% for year 2011–2015, respectively. The 1-year cumulative incidence of stroke in patients with PAD were 2.71%, 2.71%, 1.95% and 1.81%, for the 1997–2000, 2001–2005, 2006–2010 and 2011–2015 year groups, respectively. Likewise, the age-standardised incidence rates showed increasing trends of AF during the study period, whereas trends of stroke demonstrated a decline. During study, the initiation of cholesterol-lowering agents and clopidogrel increased markedly from 7.0% to 51.3% and 0.1% to 5.9%, whereas use of warfarin slightly dropped from 4.29% to 3.21%.

Conclusions

The incidence of AF in patients with PAD has significantly increased over time, whereas a marked decline has occurred in the incidence of stroke. This may suggest that the secondary prevention strategies aimed at reducing risk of stroke are broadly effective.

Validation of the cardiovascular risk model NORRISK 2 in South Asians and people with diabetes

OBJECTIVES

To evaluate the predictive ability of the previously published NORRISK 2 cardiovascular risk model in Norwegian-born and immigrants born in South Asia living in Norway, and to add information about diabetes and ethnicity in an updated model for South Asians and diabetics (NORRISK 2-SADia). Design. We included participants (30-74 years) born in Norway (n = 13,885) or South Asia (n = 1942) from health surveys conducted in Oslo 2000-2003. Cardiovascular disease (CVD) risk factor information including self-reported diabetes was linked with information on subsequent acute myocardial infarction (AMI) and acute cerebral stroke in hospital and mortality registry data throughout 2014 from the nationwide CVDNOR project. We developed an updated model using Cox regression with diabetes and South Asian ethnicity as additional predictors. We assessed model performance by Harrell's C and calibration plots. Results. The NORRISK 2 model underestimated the risk in South Asians in all quintiles of predicted risk. The mean predicted 13-year risk by the NORRISK 2 model was 3.9% (95% CI 3.7-4.2) versus observed 7.3% (95% CI 5.9-9.1) in South Asian men and 1.1% (95% CI 1.0-1.2) versus 2.7% (95% CI 1.7-4.2) observed risk in South Asian women. The mean predictions from the NORRISK 2-SADia model were 7.2% (95% CI 6.7-7.6) in South Asian men and 2.7% (95% CI 2.4-3.0) in South Asian women. Conclusions. The NORRISK 2-SADia model improved predictions of CVD substantially in South Asians, whose risks were underestimated by the NORRISK 2 model. The NORRISK 2-SADia model may facilitate more intense preventive measures in this high-risk population.

Model-Based Algorithms for Detecting Peripheral Artery Disease Using Administrative Data From an Electronic Health Record Data System: Algorithm Development Study

Background

Peripheral artery disease (PAD) affects 8 to 10 million Americans, who face significantly elevated risks of both mortality and major limb events such as amputation. Unfortunately, PAD is relatively underdiagnosed, undertreated, and underresearched, leading to wide variations in treatment patterns and outcomes. Efforts to improve PAD care and outcomes have been hampered by persistent difficulties identifying patients with PAD for clinical and investigatory purposes.

Objective

The aim of this study is to develop and validate a model-based algorithm to detect patients with peripheral artery disease (PAD) using data from an electronic health record (EHR) system.

Methods

An initial query of the EHR in a large health system identified all patients with PAD-related diagnosis codes for any encounter during the study period. Clinical adjudication of PAD diagnosis was performed by chart review on a random subgroup. A binary logistic regression to predict PAD was built and validated using a least absolute shrinkage and selection operator (LASSO) approach in the adjudicated patients. The algorithm was then applied to the nonsampled records to further evaluate its performance.

Results

The initial EHR data query using 406 diagnostic codes yielded 15,406 patients. Overall, 2500 patients were randomly selected for ground truth PAD status adjudication. In the end, 108 code flags remained after removing rarely- and never-used codes. We entered these code flags plus administrative encounter, imaging, procedure, and specialist flags into a LASSO model. The area under the curve for this model was 0.862.

Conclusions

The algorithm we constructed has two main advantages over other approaches to the identification of patients with PAD. First, it was derived from a broad population of patients with many different PAD manifestations and treatment pathways across a large health system. Second, our model does not rely on clinical notes and can be applied in situations in which only administrative billing data (eg, large administrative data sets) are available. A combination of diagnosis codes and administrative flags can accurately identify patients with PAD in large cohorts.

Diagnostic tests and treatment procedures performed prior to cardiovascular death in individuals with severe mental illness

OBJECTIVE

To examine whether severe mental illnesses (i.e., schizophrenia or bipolar disorder) affected diagnostic testing and treatment for cardiovascular diseases in primary and specialized health care.

METHODS

We performed a nationwide study of 72 385 individuals who died from cardiovascular disease, of whom 1487 had been diagnosed with severe mental illnesses. Log-binomial regression analysis was applied to study the impact of severe mental illnesses on the uptake of diagnostic tests (e.g., 24-h blood pressure, glucose/HbA1c measurements, electrocardiography, echocardiography, coronary angiography, and ultrasound of peripheral vessels) and invasive cardiovascular treatments (i.e., revascularization, arrhythmia treatment, and vascular surgery).

RESULTS

Patients with and without severe mental illnesses had similar prevalences of cardiovascular diagnostic tests performed in primary care, but patients with schizophrenia had lower prevalences of specialized cardiovascular examinations (prevalence ratio (PR) 0.78; 95% CI 0.73-0.85). Subjects with severe mental illnesses had lower prevalences of invasive cardiovascular treatments (schizophrenia, PR 0.58; 95% CI 0.49-0.70, bipolar disorder, PR 0.78; 95% CI 0.66-0.92). The prevalence of invasive cardiovascular treatments was similar in patients with and without severe mental illnesses when cardiovascular disease was diagnosed before death.

CONCLUSION

Better access to specialized cardiovascular examinations is important to ensure equal cardiovascular treatments among individuals with severe mental illnesses.

Adipose tissue content of alpha-linolenic acid and development of peripheral artery disease: a Danish case-cohort study

PURPOSE

The aim of this study was to investigate the association between adipose tissue content of the plant-derived n-3 fatty acid, alpha-linolenic acid, and the rate of incident peripheral artery disease (PAD).

METHODS

We conducted a case-cohort study nested within the Danish Diet, Cancer and Health cohort (n = 57,053), which was established between 1993 and 1997. Potential PAD cases were identified using linkage with The Danish National Patient Register and all potential cases were validated. Adipose tissue samples from the buttock were collected at baseline and fatty acid composition was determined in cases and in a random sample (n = 3500) from the cohort by gas chromatography. Statistical analyses were performed using weighted Cox regression allowing for different baseline hazards among sexes.

RESULTS

During a median of 13.5 years of follow-up, we identified 863 PAD cases with complete information. The median adipose tissue content of ALA in the sub-cohort (n = 3197) was 0.84% (interquartile range 0.73-0.94%) of total fatty acids. In multivariate analyses including adjustment for established risk factors, we observed a U-shaped association between ALA in adipose tissue and rate of PAD, but the association was not statistically significant (P = 0.131). Similar pattern of associations were observed between ALA content in adipose tissue and the rate of PAD among men and women.

CONCLUSIONS

We found indications of a U-shaped association between adipose tissue content of ALA and the rate of PAD, but the association was not statistically significant.

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.

Ischemic Stroke in Adults With Congenital Heart Disease: A Population-Based Cohort Study

Background

Congenital heart disease (CHD) is associated with risk factors for ischemic stroke including cardiac arrhythmias and heart failure. However, few long‐term follow‐up data exist on ischemic stroke risk and associated mortality in adults with CHD.

Methods and Results

Using Danish nationwide registries, we identified individuals aged ≥18 years diagnosed with CHD, at any age, from 1963 to 2017 and a sex and birth year‐matched (1:10) general population comparison cohort. We computed risks, as well as sex and birth year‐adjusted hazard ratios (aHRs) for ischemic stroke and 30‐day post‐stroke mortality in CHD adults compared with the general population. Analyses were stratified according to age <60 years (young) and ≥60 years (older). We identified 16 836 adults with CHD. The risk of ischemic stroke at age 60 years was 7.4% in the CHD cohort and 2.9% in the general population cohort. The adjusted hazard ratios for ischemic stroke compared with the general population was 3.8 (95% CI: 3.3–4.3) in young CHD adults and 1.6 (95% CI: 1.4–1.9) in older CHD adults. The adjusted hazard ratios for post‐stroke mortality compared with the general population was 2.3 (95% CI: 1.2–4.4) in young CHD adults and 1.3 (95% CI: 0.9–1.9) in older CHD adults.

Conclusions

Both younger and older CHD adults have an increased risk of ischemic stroke and by 60 years of age 7.4% of CHD adults will have had an ischemic stroke. Post‐stroke mortality was also increased in CHD adults compared with the general population.

Intake of α-linolenic acid is not consistently associated with a lower risk of peripheral artery disease: results from a Danish cohort study

Intake of the plant-derived n-3 fatty acid α-linolenic acid (ALA) has been associated with anti-atherosclerotic properties. However, information on the association between ALA intake and development of peripheral artery disease (PAD) is lacking. In this follow-up study, we investigated the association between dietary intake of ALA and the rate of PAD among middle-aged Danish men and women enrolled into the Danish Diet, Cancer and Health cohort between 1993 and 1997. Incident PAD cases were identified through the Danish National Patient Register. Intake of ALA was assessed using a validated FFQ. Statistical analyses were performed using Cox proportional hazard regression allowing for separate baseline hazards among sexes and adjusted for established risk factors for PAD. During a median of 13·6 years of follow-up, we identified 950 valid cases of PAD with complete information on covariates. The median energy-adjusted ALA intake within the cohort was 1·76 g/d (95 % central range: 0·94-3·28). In multivariable analyses, we found no statistically significant association between intake of ALA and the rate of PAD (P = 0·339). Also, no statistically significant associations were observed in analyses including additional adjustment for co-morbidities and in sex-specific analyses. In supplemental analyses with additional adjustment for potential dietary risk factors, we found a weak inverse association of PAD with ALA intake above the median, but the association was not statistically significant (P = 0·314). In conclusion, dietary intake of ALA was not consistently associated with decreased risk of PAD.

Pediatric autoimmune encephalitis in Denmark during 2011-17: A nationwide multicenter population-based cohort study

BACKGROUND

The incidence of pediatric autoimmune encephalitis (AIE) is unknown. Our aim was to assess the incidence of pediatric AIE in Denmark 2011-17.

METHODS

In a nationwide population-based setting, we retrieved data on all children tested for AIE before age 18 years. We reviewed medical records in a) children with AIE antibodies (n = 18) to assess whether children fulfilled the AIE consensus criteria, b) children tested negative for AIE antibodies who were registered with an AIE diagnostic code to estimate the incidence of "antibody negative but probable AIE", and c) a reference cohort (n = 596) to determine the positive predictive value of International Classification of Diseases (ICD) codes used for anti-NMDAR encephalitis.

RESULTS

375 children were tested for AIE 2011-17 (median age 11.1 years; 54% girls); 18 children (5%) had AIE antibodies (percentage tested positive): CSF GAD₆₅-IgG (3.1%), plasma NMDAR-IgG (2.8%), CSF NMDAR-IgG (1.8%), plasma GAD₆₅-IgG (1.0%), and plasma CASPR2-IgG (0.4%). Five children fulfilled the criteria for probably/definite anti-NMDAR encephalitis (incidence: 0.07/100,000 person-years; 95% CI = 0.03-0.17), and 4 children with anti-GAD₆₅ associated AIE (incidence = 0.055/100,000 person-years, 95% CI = 0.021-0.15). The incidence of "antibody negative but probable AIE" was 0.055/100,000 person-years (95% CI = 0.021-0.15). The positive predictive value of ICD diagnostic codes used for anti-NMDAR encephalitis was 8%.

CONCLUSIONS

We diagnosed only children with anti-NMDAR, anti-GAD₆₅, and "antibody negative but probable AIE". Before examining AIE antibodies, clinical presentation, paraclinical studies (CSF, EEG, and MRI), and incidence of pediatric AIEs should be considered. Updating the ICD to include AIE codes is warranted.

Undiagnosed cardiovascular disease prior to cardiovascular death in individuals with severe mental illness

OBJECTIVE

To examine whether individuals with schizophrenia (SCZ) or bipolar disorder (BD) had equal likelihood of not being diagnosed with cardiovascular disease (CVD) prior to cardiovascular death, compared to individuals without SCZ or BD.

METHODS

Multivariate logistic regression analysis including nationwide data of 72 451 cardiovascular deaths in the years 2011-2016. Of these, 814 had a SCZ diagnosis and 673 a BD diagnosis in primary or specialist health care.

RESULTS

Individuals with SCZ were 66% more likely (OR: 1.66; 95% CI: 1.39-1.98), women with BD were 38% more likely (adjusted OR: 1.38; 95% CI: 1.04-1.82), and men with BD were equally likely (OR: 0.88, 95% CI: 0.63-1.24) not to be diagnosed with CVD prior to cardiovascular death, compared to individuals without SMI. Almost all (98%) individuals with SMI and undiagnosed CVD had visited primary or specialized somatic health care prior to death, compared to 88% among the other individuals who died of CVD.

CONCLUSION

Individuals with SCZ and women with BD are more likely to die due to undiagnosed CVD, despite increased risk of CVD and many contacts with primary and specialized somatic care. Strengthened efforts to prevent, recognize, and treat CVD in individuals with SMI from young age are needed.

A Population-Based Study of Incidence, Presentation, Management and Outcome of Primary Thromboembolic Ischemia in the Upper Extremity

OBJECTIVES

To investigate the epidemiology of acute upper limb thromboembolism in a well-defined Norwegian population.

METHODS

This study was a retrospective, single-center, observational population-based cohort study of acute upper limb thromboembolism. The study included all patients from the hospital's primary catchment area from January 2000 to December 2015. Age- and gender-adjusted incidence rates were calculated using population demographics from Statistics Norway.

RESULTS

A total of 54 patients were identified, of which 49 were included in the analyses: 27 (55%) females (median age 83 years, range 40-96) and 22 (45%) males (median age 70 years, range 42-95) (P = .053). The adjusted incidence rate for the period was 1.6 patients per 100,000 inhabitants per year (95% confidence interval 1.2-2.2) and did not change significantly during the period studied. Atrial fibrillation was detected by electrocardiography in 30 (61%) patients; in this group, 10 patients were on warfarin but only two had an international normalized ratio > 1.9 and the remaining 20 were not anticoagulated. Altogether, 38 (78%) patients underwent surgery, 1 (2%) was treated with thrombolysis, and the remaining patients were treated conservatively; no amputations were performed. Four patients (8%) died within 30 days, and 12 of the surviving 45 patients (27%) had recurrent thromboembolism.

CONCLUSION

The incidence rate was stable during the study period. Patients with upper limb thromboembolism due to atrial fibrillation were inadequately anticoagulated. One in four patients experienced a recurrent thromboembolic event. Lifelong anticoagulation should be considered in all patients with upper limb thromboembolism.

Treatment of aortic aneurysms registered in Swedvasc: Development reflected in a national vascular registry with an almost 100% coverage

Swedvasc is a registry for vascular surgical procedures, both open and endovascular. It was started in 1987 and since 1994 the whole population of Sweden is covered, at present around 10 million inhabitants. In a recent external validation, it was found to be highly accurate with abdominal aortic aneurysm surgery correctly reported in >96%. In this paper various factors explaining the almost 100% coverage are discussed, one important being that the registry has been developed and maintained within the profession of vascular surgery and not dictated by authorities. Another factor of importance is the possibility to use data in various research projects and so far 15 PhD theses have used Swedvasc data. To exemplify the practical use of the registry, the treatment of abdominal aortic aneurysms is scrutinized and among the various complications abdominal compartment syndrome is analyzed. Several significant temporal changes have been observed over the almost 25 years of Swedvasc: increasing use of endovascular surgery, treatment of aneurysms detected by screening , decreasing treatment for rupture, improved outcome, increasing treatment of older patients and patients with comorbid conditions. In conclusion, a high quality national vascular registry can be valid with high compliance and can be used to study population-based development of treatment and outcome. It can also be used to perform international comparisons with other registries, thereby getting an indication of the quality of care.

Pediatric acquired demyelinating syndromes: a nationwide validation study of the Danish National Patient Register

Objective

To validate the Danish National Patient Register’s (NPR) diagnoses of pediatric acquired demyelinating syndromes (ADS) including multiple sclerosis (MS).

Study design and setting

We identified ADS diagnostic groups using International Classification of Diseases (ICD) codes and reviewed medical records to validate the NPR diagnoses during 2008–2015.

Results

Among 409 children in the study, 184 children had a validated and final ADS diagnosis after reviewing medical records as follows: optic neuritis (ON; n=46), transverse myelitis (TM; n=16), acute disseminated encephalomyelitis (ADEM; n=50), clinically isolated syndrome (CIS) including dissemination in space (CIS [DIS]) but not dissemination in time (n=6), neuromyelitis optica spectrum disorder (NMOsd; n=5), and MS (n=61). During the mean follow-up of 4.6 years, 33% of children initially diagnosed with monophasic ADS progressed to MS. Positive predictive value (PPV) was 0.71 (95% confidence interval [CI] =0.62–0.80) for ON, 0.64 (95% CI =0.43–0.82) for TM, 0.93 (95% CI =0.84–0.98) for MS, 0.27 (95% CI =0.19–0.35) for CIS, 0.43 (95% CI =0.10–0.82) for NMOsd, and 0.15 (95% CI =0.10–0.20) for ADEM. Assuming complete coverage for non-MS ADS, the sensitivity was 0.99 (95% CI =0.93–1.00) for ON, 0.83 (95% CI =0.36–1.00) for CIS (DIS), and 0.80 (95% CI =0.56–0.94) for TM, but only 0.58 (95% CI =0.43–0.72) for ADEM and 0.60 (95% CI =0.15–0.95) for NMOsd.

Conclusion

PPV was high for MS and considered acceptable for ON and TM; therefore, these ICD revision 10 (ICD-10) codes from the NPR are useful for epidemiological studies. Conversely, PPV was low for CIS and ADEM; NMOsd was inconclusive.

Peripheral Arterial Disease Genetics: Progress to Date and Challenges Ahead

PURPOSE OF REVIEW

In this paper, we review the progress made thus far in research related to the genetics of peripheral arterial disease (PAD) by detailing efforts to date in heritability, linkage analyses, and candidate gene studies. We further summarize more contemporary genome-wide association studies (GWAS) and epigenetic studies of PAD. Finally, we review current challenges and future avenues of advanced research in PAD genetics including whole genome sequencing studies.

RECENT FINDINGS

Studies have estimated the heritability of PAD to be moderate, though the contribution to this heritability that is independent of traditional cardiovascular risk factors remains unclear. Recent efforts have identified SNPs associated with PAD in GWAS analyses, but these have yet to be replicated in independent studies. Much remains to be discovered in the field of PAD genetics. An improved understanding of the genetic foundation for PAD will allow for earlier diagnosis of disease and a more complete pathophysiological understanding of the mechanisms of the disease leading to novel therapeutic interventions. Future avenues for success will likely arise from very large-scale GWAS, whole genome sequencing, and epigenetic studies involving very well-characterized cohorts.