Optimizing the Definitions of Stroke, Transient Ischemic Attack, and Infarction for Research and Application in Clinical Practice

BACKGROUND AND PURPOSE

Until now, stroke and transient ischemic attack (TIA) have been clinically based terms which describe the presence and duration of characteristic neurological deficits attributable to intrinsic disorders of particular arteries supplying the brain, retina, or (sometimes) the spinal cord. Further, infarction has been pathologically defined as death of neural tissue due to reduced blood supply. Recently, it has been proposed we shift to definitions of stroke and TIA determined by neuroimaging results alone and that neuroimaging findings be equated with infarction.

METHODS

We examined the scientific validity and clinical implications of these proposals using the existing published literature and our own experience in research and clinical practice.

RESULTS

We found that the proposals to change to imaging-dominant definitions, as published, are ambiguous and inconsistent. Therefore, they cannot provide the standardization required in research or its application in clinical practice. Further, we found that the proposals are scientifically incorrect because neuroimaging findings do not always correlate with the clinical status or the presence of infarction. In addition, we found that attempts to use the proposals are disrupting research, are otherwise clinically unhelpful and do not solve the problems they were proposed to solve.

CONCLUSION

We advise that the proposals must not be accepted. In particular, we explain why the clinical focus of the definitions of stroke and TIA should be retained with continued sub-classification of these syndromes depending neuroimaging results (with or without other information) and that infarction should remain a pathological term. We outline ways the established clinically based definitions of stroke and TIA, and use of them, may be improved to encourage better patient outcomes in the modern era.

Impaired kidney function is associated with intraplaque hemorrhage in patients undergoing carotid endarterectomy

BACKGROUND AND AIMS

Previously, we showed that patients undergoing carotid endarterectomy have an increased risk for major atherosclerotic events in the presence of moderate or poor kidney function. Acceleration of vascular inflammatory responses is considered to be causally involved in progression of atherogenesis and poor outcome in chronic kidney disease patients. The association between kidney function and plaque composition has not been thoroughly investigated yet. The aim of this study was to investigate the association between kidney function and atherosclerotic plaque composition in patients undergoing carotid endarterectomy.

METHODS

Atherosclerotic plaques, harvested from 1796 patients who underwent carotid endarterectomy, were immunohistochemically stained for macrophages, smooth muscle cells, calcifications, collagen, microvessels, lipid core size and intraplaque hemorrhage. Cytokines were measured in plaque and plasma and associated with kidney function. Quantitative proteomics were performed on 40 carotid plaques and associated with kidney function.

RESULTS

Decreased kidney function was associated with increased odds ratio of intraplaque hemorrhage, OR 1.15 (95% CI; 1.02-1.29 (p = 0.024)) and increased odds ratio of fibrous-atheromatous plaques (plaques with lipid core presenting more than 10% of total plaque surface) OR 1.21 (95% CI; 1.07-1.38 (p = 0.003)) per decrease of 20 points in eGFR. Proteomics revealed that decreased kidney function was associated with upregulation of the classical pathway of the complement system and the intrinsic pathway of the coagulation system.

CONCLUSIONS

Decreased kidney function was associated with plaque hemorrhage but not with inflammatory plaque characteristics. Our data suggests that other pathways than the inflammation-pathway are involved in plaque vulnerability and poor outcome in patients with decreased kidney function.

High Levels of (Un)Switched Memory B Cells Are Associated With Better Outcome in Patients With Advanced Atherosclerotic Disease

BACKGROUND

Atherosclerosis is an inflammatory lipid disorder and the main underlying pathology of acute ischemic events. Despite a vast amount of data from murine atherosclerosis models, evidence of B-cell involvement in human atherosclerotic disease is limited. We therefore investigated the association of circulating B-cell subtypes with the occurrence of secondary cardiovascular events in advanced atherosclerotic disease.

METHODS AND RESULTS

This cohort study consists of 168 patients who were included in the Athero-Express biobank between 2009 and 2011. Before surgery, peripheral blood mononuclear cells were isolated and stored in liquid nitrogen. After gentle thawing of the peripheral blood mononuclear cells, different B-cell subtypes including naïve, (un)switched memory, and CD27+CD43+ B1-like B cells, were analyzed by flow cytometry. Univariable and multivariable Cox proportional hazard models were used to analyze associations between B-cell subtypes, circulating antibodies and secondary cardiovascular manifestations during the 3-year follow-up period. Mean age was 70.1±9.6 years, males represented 62.8% of the population, and 54 patients had secondary manifestations during follow-up. High numbers of unswitched memory cells were protective against secondary outcome (hazard ratio, 0.30 [95% CI, 0.13-0.69]; P<0.01). Similar results were obtained for the switched memory cells that also showed to be protective against secondary outcome (hazard ratio, 0.33 [95% CI, 0.14-0.77]; P=0.01).

CONCLUSIONS

A high number of (un)switched memory B cells is associated with better outcome following carotid artery endarterectomy. These findings suggest a potential role for B-cell subsets in prediction and prevention of secondary cardiovascular events in patients with atherosclerosis.

Growth Differentiation Factor 15 Is Associated With Major Amputation and Mortality in Patients With Peripheral Artery Disease

Background

Peripheral artery disease (PAD) is one of the most common clinical presentations of atherosclerosis, and its prevalence is still increasing. Despite improvement of health care, morbidity and mortality risks remain high, including the risk of amputation. GDF15 (growth differentiation factor 15) is a member of the transforming growth factor family that is involved in apoptosis and inflammation; therefore, GDF15 is a potential biomarker to identify patients at high risk of adverse clinical outcomes.

Methods and Results

Circulating GDF15 levels were measured using a multiplex immunoassay in patients with critical limb ischemia and PAD from 2 different patient cohorts that included patients with clinically manifest PAD: the JUVENTAS (Rejuvenating Endothelial Progenitor Cells via Transcutaneous Intra‐Arterial Supplementation) trial (n=160, 67 major events; critical limb ischemia) and the Athero‐Express Biobank (n=386, 64 major events; PAD). Kaplan–Meier curves demonstrated that high levels of GDF15 were associated with increased risk of major events, defined as major amputation (at or above the ankle joint) and all‐cause mortality, in both cohorts (highest versus lowest, JUVENTAS: hazard ratio: 4.01 [95% confidence interval, 2.05–7.84; P<0.0001]; Athero‐Express: hazard ratio: 3.27 [95% confidence interval, 1.64–6.54; P=0.0008]). In the JUVENTAS trial, this was more pronounced in women. Cox proportional multivariable regression models with median follow‐up of 3 years, corrected for common confounders, showed hazard ratios of 1.70 (95% confidence interval, 1.18–2.69; P=0.0053) and 1.57 (95% confidence interval, 1.02–2.41; P=0.041) per 2.78‐fold increase of GDF15 in JUVENTAS and Athero‐Express, respectively.

Conclusions

High GDF15 levels are associated with increased risk of major amputation and/or death in PAD patients. GDF15 levels could be of additive value to identify patients who are at high risk of amputation or death and could help guide treatment choices.

Preoperative anemia is associated with mortality after carotid endarterectomy in symptomatic patients

OBJECTIVE

Preoperative anemia and blood transfusions are associated with worse outcomes after surgery. However, the impact of preoperative anemia and transfusions on outcomes after carotid endarterectomy (CEA) is unknown.

METHODS

CEA patients from 2011 to 2015 in the American College of Surgeons National Surgical Quality Improvement Program Targeted Vascular module were compared by the presence of preoperative anemia (hematocrit <36%) after stratification by symptom status. Multivariable analysis accounted for differences in baseline characteristics. We included an interaction term in our multivariable model to assess whether the effect of anemia differed significantly between patients who received a perioperative transfusion and those who did not, with 30-day mortality as our primary outcome.

RESULTS

Of 16,068 patients, 6734 (42%) were symptomatic, of whom 1500 (22%) had anemia. Of the 9334 asymptomatic patients, 1935 (21%) had anemia. Both symptomatic and asymptomatic anemic patients were more likely to be transfused perioperatively compared with nonanemic patients, with 7.0% vs 0.4%, and 5.8% vs 0.7% (both P < .001). Among symptomatic patients, those with anemia compared with those without had a higher rate of 30-day mortality (2.5% vs 0.7%; P < .001). After adjustment, anemic symptomatic patients had a higher 30-day mortality risk (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.9-5.0; P < .001) compared with nonanemic symptomatic patients. In addition, in symptomatic patients, we found a significant interaction between anemia and perioperative transfusion on the outcome of 30-day mortality (P = .004), with a higher risk in perioperatively transfused symptomatic patients with anemia (OR, 7.8; 95% CI, 3.4-18.0; P < .001) than in symptomatic patients with anemia who did not receive a perioperative transfusion (OR, 2.3; 95% CI, 1.4-3.9; P = .002). In asymptomatic patients, anemic and nonanemic patients had comparable 30-day mortality rates (0.9% vs 0.6%; P = .2). After adjustment, anemia was not associated with 30-day mortality in asymptomatic patients (OR, 1.0; 95% CI, 0.5-2.0; P = .9), nor did we identify an interaction between anemia and perioperative transfusion in asymptomatic patients (P = .1). Patients who received a preoperative transfusion had a higher 30-day mortality rate than anemic patients not receiving preoperative transfusion in both symptomatic (n = 31, 9.7% vs 2.5%; P = .04) and asymptomatic patients (n = 21, 9.5% vs 0.9%; P = .02).

CONCLUSIONS

Preoperative anemia is a risk factor for 30-day mortality after CEA in symptomatic patients but not in asymptomatic patients. These results should be factored into the selection of symptomatic patients for CEA and dissuade treatment of asymptomatic patients scheduled for CEA who need a preoperative transfusion.

Incidence of cardiovascular events and vascular interventions in patients with type 2 diabetes

OBJECTIVE

Diabetes mellitus is associated with an increased risk for cardiovascular morbidity and mortality. The vascular burden in terms of incidence of cardiovascular events (CVE) and vascular interventions is however poorly quantified. In this study we evaluated the incidence rates of CVE and vascular interventions in patients with type 2 diabetes (T2DM) with and without cardiovascular disease (CVD) in comparison to patients without type 2 diabetes.

RESEARCH DESIGN AND METHODS

In a cohort of 9.808 high-risk patients with and without cardiovascular disease and type 2 diabetes originated from the ongoing, single-center prospective SMART (Second Manifestations of ARTerial disease) cohort, the number and incidence rates of CVE and interventions were calculated. The incidence rates were adjusted for confounders using Poisson regression models. CVE were defined as vascular death, stroke and myocardial infarction (MI). Interventions were defined as percutaneous coronary intervention, coronary artery bypass grafting, percutaneous transluminal angioplasty or stenting of the peripheral arteries and amputation.

RESULTS

Patients with T2DM and CVD had a 4-fold higher incidence rate of CVE and a 8-fold higher incidence rate of vascular interventions compared to high-risk patients without T2DM and CVD after adjusting for confounders. The incidence rate for the composite of non-fatal MI, non-fatal stroke and vascular death was 5.8 per 1000person-years in patients without T2DM or CVD at baseline, 15.2 per 1000person-years in patients with T2DM but without CVD at baseline, 26.0 per 1000person-years in patients without T2DM but with CVD and 40.7 per 1000person-years in patients with both T2DM and CVD at baseline. A similar increasing incidence rate was seen for all vascular interventions from patients without T2DM or CVD to patients with both T2DM and CVD.

CONCLUSIONS

Patients with type 2 diabetes or CVD are subject to an increased incidence of cardiovascular events and interventions compared to high-risk patients without type 2 diabetes or vascular disease. Patients with type 2 diabetes and CVD have the highest incidence of new cardiovascular diseases and vascular interventions when compared to patients without type 2 diabetes and CVD. These results underline the need for optimal risk factor treatment as well as the need for new prevention and treatment strategies in this very high risk population.

Risk Factors for Recurrent Cardiovascular Events Before Age 65 Years or Within 2.5 Years of a Recent First Cardiovascular Event

The aim of this study was to quantify the relation between classical risk factors (smoking, diabetes, BMI, waist circumference, blood pressure, and lipids), risk factor targets, and risk of recurrent major atherosclerotic cardiovascular events (MACE). This was first done for recurrent MACE ≤65 years in patients aged <60 years and second for recurrent MACE ≤2.5 years after a first cardiovascular event. Data were used from the Second Manifestations of Arterial Disease study (n = 5,115), a prospective cohort of patients with a recent (≤1 year) first cardiovascular event. During follow-up, 746 recurrent MACE occurred. Smoking (hazard ratio [HR] 1.43, 95% CI 1.11 to 1.84), diabetes (HR 1.83, 95% CI 1.11 to 1.84), diastolic blood pressure (>90 vs 70 to 90 mm Hg, HR 1.54, 95% CI 1.15 to 2.07), and high-density lipoprotein cholesterol (≤1.0 vs >1.0 mmol/L, HR 1.34, 95% CI 1.03 to 1.76) were related to increased risk of recurrent MACE ≤65 years in patients aged <60 years. Smoking (HR 1.65, 95% CI 1.23 to 2.22), physical inactivity (highest vs lowest tertile, HR 1.48, 95% CI 1.05 to 2.09), body mass index (per kg/m², HR 1.04, 95% CI 1.00 to 1.08), diastolic blood pressure (>90 vs 70 to 90 mm Hg, HR 1.61, 95% CI 1.17 to 2.21), low-density lipoprotein cholesterol (per mmol/L, HR 1.18, 95% CI 1.02 to 1.37), and non-high-density lipoprotein cholesterol (per mmol/L, HR 1.15, 95% CI 1.03 to 1.28) were related to recurrent MACE ≤2.5 years of follow-up. In conclusion, in patients with a recent cardiovascular event, smoking, blood pressure, and lipids are related to increased risk of recurrent cardiovascular events at young age or within a short time span, and intensive treatment of modifiable risk factors may contribute to prevent recurrent MACE in these patients.

The impact of contralateral carotid artery stenosis on outcomes after carotid endarterectomy

OBJECTIVE

Patients with contralateral carotid occlusion (CCO) have been excluded from randomized clinical trials because of a deemed high risk for adverse neurologic outcomes with carotid endarterectomy (CEA). Evidence for this rationale is limited and conflicting. Therefore, we aimed to compare outcomes after CEA between patients with and without CCO and varying degrees of contralateral carotid stenosis (CCS).

METHODS

We identified patients undergoing CEA from 2003 to 2015 in the Vascular Study Group of New England (VSGNE) registry. Patients were stratified by preoperative symptom status and presence of CCO. Multivariable analysis was used to account for differences in demographics and comorbidities. Our primary outcome was 30-day stroke/death risk.

RESULTS

Of 15,487 patients we identified who underwent CEA, 10,377 (67%) were asymptomatic. CCO was present in 914 patients, of whom 681 (75%) were asymptomatic. Overall, the 30-day stroke/death was 2.0% for symptomatic patients (CCO: 2.6%) and 1.1% for asymptomatic patients (CCO: 2.3%). After adjustment, including symptom status, CCO was associated with higher 30-day stroke/death (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.4-3.3; P = .001), any in-hospital stroke (OR, 2.8; 95% CI, 1.7-4.6; P < .001), in-hospital ipsilateral stroke (OR, 2.2; 95% CI, 1.2-4.0; P = .02), in-hospital contralateral stroke (OR, 5.1; 95% CI, 2.2-11.4; P < .001), and prolonged length of stay (OR, 1.6; 95% CI, 1.3-1.9; P < .001). CCS of 80% to 99% was only associated with a prolonged length of stay (OR, 1.3; 95% CI, 1.1-1.6; P = .01), not with in-hospital stroke. Neither CCO nor CCS was associated with 30-day mortality.

CONCLUSIONS

Although CCO increases the risk of 30-day stroke/death, in-hospital strokes, and prolonged length of stay after CEA, the 30-day stroke/death rates in symptomatic and asymptomatic patients with CCO remain within the recommended thresholds set by the 14 societies' guideline document. Thus, CCO should not qualify as a high-risk criterion for CEA. Moreover, there is no evidence that patients with CCO have lower stroke/death rates after carotid artery stenting than after CEA. We believe that CEA remains a valid and safe option for patients with CCO and that CCO should not be applied as a criterion to promote carotid artery stenting per se.

Long-term vagal stimulation for heart failure: Eighteen month results from the NEural Cardiac TherApy foR Heart Failure (NECTAR-HF) trial

BACKGROUND

The NECTAR-HF study evaluated safety and feasibility of vagal nerve stimulation (VNS) for the treatment of heart failure patients. The first six-month randomized phase of the study did not show improvement in left ventricular remodelling in response to VNS. This study reports the 18-month results and provides novel findings aiming to understand the lack of efficacy of VNS, including a new technique assessing the effects of VNS.

METHODS

Ninety-six patients were randomized 2:1 to active or inactive VNS for 6months, thereafter VNS was activated for all patients. The primary safety endpoint was 18-month all-cause mortality.

RESULTS

Ninety-one patients continued in the long-term evaluation with active VNS. The on-therapy survival estimate at 18months was 95% with a 95% one-sided lower confidence limit of 91%, (better than the predefined criterion). Left ventricular systolic volume decreased in the crossover group (VNS OFF→ON; 144±37 to 139±40, p<0.05) after VNS activation; LVESD (5.02±0.77 to 4.96±0.82, p>0.05) and LVEF (33.2±4.9 to 33.3±6.5, p>0.05) did not change. A new technique to detect subtle heart rate changes during Holter recordings, i.e. "heat maps", revealed that VNS evoked heart rate response in only 13/106 studies (12%) at 6 and 12months with active VNS.

CONCLUSIONS

Although a favourable long-term safety profile was found, improvements in the efficacy endpoints were not seen with VNS. A new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibres responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models.

Proteins in Preservation Fluid as Predictors of Delayed Graft Function in Kidneys from Donors after Circulatory Death

BACKGROUND AND OBJECTIVES

Kidney transplantation is the preferred treatment for ESRD, and donor kidney shortage urges proper donor-recipient matching. Zero-hour biopsies provide predictive values for short- and long-term transplantation outcomes, but are invasive and may not reflect the entire organ. Alternative, more representative methods to predict transplantation outcome are required. We hypothesized that proteins accumulating in preservation fluid during cold ischemic storage can serve as biomarkers to predict post-transplantation graft function.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Levels of 158 proteins were measured in preservation fluids from kidneys donated after circulatory death (Maastricht category III) collected in two Dutch centers (University Medical Center Utrecht and Erasmus Medical Center Rotterdam) between 2013 and 2015. Five candidate biomarkers identified in a discovery set of eight kidneys with immediate function (IF) versus eight with delayed graft function (DGF) were subsequently analyzed in a verification set of 40 additional preservation fluids to establish a prediction model.

RESULTS

Variables tested for their contribution to a prediction model included five proteins (leptin, periostin, GM-CSF, plasminogen activator inhibitor-1, and osteopontin) and two clinical parameters (recipient body mass index [BMI] and dialysis duration) that distinguished between IF and DGF in the discovery set. Stepwise multivariable logistic regression provided a prediction model on the basis of leptin and GM-CSF. Receiver operating characteristic analysis showed an area under the curve (AUC) of 0.87, and addition of recipient BMI generated a model with an AUC of 0.89, outperforming the Kidney Donor Risk Index and the DGF risk calculator, showing AUCs of 0.55 and 0.59, respectively.

CONCLUSIONS

We demonstrate that donor kidney preservation fluid harbors biomarkers that, together with information on recipient BMI, predict short-term post-transplantation kidney function. Our approach is safe, easy, and performs better than current prediction algorithms, which are only on the basis of clinical parameters.

Genome-wide meta-analysis of 241,258 adults accounting for smoking behaviour identifies novel loci for obesity traits

Few genome-wide association studies (GWAS) account for environmental exposures, like smoking, potentially impacting the overall trait variance when investigating the genetic contribution to obesity-related traits. Here, we use GWAS data from 51,080 current smokers and 190,178 nonsmokers (87% European descent) to identify loci influencing BMI and central adiposity, measured as waist circumference and waist-to-hip ratio both adjusted for BMI. We identify 23 novel genetic loci, and 9 loci with convincing evidence of gene-smoking interaction (GxSMK) on obesity-related traits. We show consistent direction of effect for all identified loci and significance for 18 novel and for 5 interaction loci in an independent study sample. These loci highlight novel biological functions, including response to oxidative stress, addictive behaviour, and regulatory functions emphasizing the importance of accounting for environment in genetic analyses. Our results suggest that tobacco smoking may alter the genetic susceptibility to overall adiposity and body fat distribution.

Proof-of-Concept Evaluation of the SailValve Self-Expanding Deep Venous Valve System in a Porcine Model

Purpose: To evaluate the SailValve, a new self-expanding deep venous valve concept based on a single polytetrafluoroethylene cusp floating up and down in the bloodstream like a sail, acting as a flow regulator and allowing minimal reflux to reduce thrombogenicity. Methods: Both iliac veins of 5 pigs were implanted with SailValve devices; the first animal was an acute pilot experiment to show the feasibility of accurately positioning the SailValve via a femoral access. The other 4 animals were followed for 2 weeks (n=2) or 4 weeks (n=2) under a chronic implantation protocol. Patency and valve function were evaluated directly in all animals using ascending and descending phlebography after device placement and at termination in the chronic implant animals. For reasons of clinical relevance, a regimen of clopidogrel and calcium carbasalate was administered. Histological analysis was performed according to a predefined protocol by an independent pathologist. Results: Deployment was technically feasible in all 10 iliac veins, and all were patent directly after placement. No perioperative or postoperative complications occurred. Ascending phlebograms in the follow-up animals confirmed the patency of all valves after 2 or 4 weeks. Descending phlebograms showed full function in 5 of 8 valves. Limited reflux was seen in 1 valve (4-week group), and the function in the remaining 2 valves (2-week group) was insufficient because of malpositioning. No macroscopic thrombosis was noted on histology. Histology in the follow-up groups revealed a progressive inflammatory reaction to the valves. Conclusion: This animal study shows the potential of the SailValve concept with sufficient valve function after adequate positioning and no (thrombogenic) occlusions after short-term follow-up. Future research is essential to optimize valve material and long-term patency.

Circulating GDF-15 levels predict future secondary manifestations of cardiovascular disease explicitly in women but not men with atherosclerosis

BACKGROUND

Elevated serum levels of growth differentiation factor-15 (GDF-15), is an established risk factor for a range of cardiovascular diseases. We aimed to evaluate the predictive value of plasma GDF-15 as a biomarker for secondary cardiovascular events (CVE) in patients with atherosclerosis undergoing carotid endarterectomy (CEA). Secondly, we determined whether plasma GDF-15 was associated with carotid plaque characteristics.

METHODS

Circulating GDF-15 levels were determined by Luminex assay in a cohort of 1056 patients from the Athero-Express biobank. Composite endpoint was defined as major CVE, death and peripheral vascular interventions. Findings were validated in 473 patients from the independent Carotid Plaque Imaging Project biobank.

RESULTS

GDF-15 levels did not associate with secondary CVE in the total cohort. However, following a significant interaction with sex, it was found to be strongly, independently predictive of secondary CVE in women but not men (quartile 4 vs. quartile 1: HR 3.04 [95% CI 1.35-6.86], p=0.007 in women vs. HR 0.96 [95% CI 0.66-1.40], p=0.845 in men). This was also observed in the validation cohort (women: HR 2.28 [95% CI 1.04-5.05], p=0.041), albeit dependent upon renal function. In addition, GDF-15 was associated with the presence of plaque smooth muscle cells and calcification.

CONCLUSION

High circulating GDF-15 levels are predictive of secondary CVE in women but not in men with carotid atherosclerotic disease undergoing CEA, suggesting a potential use for GDF-15 as a biomarker for secondary prevention in women. Sex differences in the role of GDF-15 in atherosclerotic disease deserve further interest.

Genetic variation within the Y chromosome is not associated with histological characteristics of the atherosclerotic carotid artery or aneurysmal wall

BACKGROUND AND AIMS

Haplogroup I, a common European paternal lineage of the Y chromosome, is associated with increased risk of coronary artery disease in British men. It is unclear whether this haplogroup or any other haplogroup on the Y chromosome is associated with histological characteristics of the diseased vessel wall in other vascular manifestations of cardiovascular diseases showing a male preponderance.

METHODS

We examined Dutch men undergoing either carotid endarterectomy from the Athero-Express biobank (AE, n = 1217) or open aneurysm repair from the Aneurysm-Express biobank (AAA, n = 393). Upon resolving the Y chromosome phylogeny, each man was assigned to one of the paternal lineages based on combinations of single nucleotide polymorphisms of the male-specific region of the Y chromosome. We examined the associations between the Y chromosome and the histological characteristics of the carotid plaque and aneurysm wall, including lipid content, leukocyte infiltration and intraplaque haemorrhage, in all men.

RESULTS

A majority of men were carriers of either haplogroup I (AE: 28% AAA: 24%) or haplogroup R (AE: 59% AAA: 61%). We found no association between Y chromosomal haplogroups and histological characteristics of plaque collected from carotid arteries or tissue specimens of aneurysms. Moreover, the distribution of frequency for all Y chromosomal haplogroups in both cohorts was similar to that of a general population of Dutch men.

CONCLUSIONS

Our data show that genetic variation on the Y chromosome is not associated with histological characteristics of the plaques from carotid arteries or specimens of aneurysms in men of Dutch origin.

Rare and low-frequency coding variants alter human adult height

Height is a highly heritable, classic polygenic trait with approximately 700 common associated variants identified through genome-wide association studies so far. Here, we report 83 height-associated coding variants with lower minor-allele frequencies (in the range of 0.1-4.8%) and effects of up to 2 centimetres per allele (such as those in IHH, STC2, AR and CRISPLD2), greater than ten times the average effect of common variants. In functional follow-up studies, rare height-increasing alleles of STC2 (giving an increase of 1-2 centimetres per allele) compromised proteolytic inhibition of PAPP-A and increased cleavage of IGFBP-4 in vitro, resulting in higher bioavailability of insulin-like growth factors. These 83 height-associated variants overlap genes that are mutated in monogenic growth disorders and highlight new biological candidates (such as ADAMTS3, IL11RA and NOX4) and pathways (such as proteoglycan and glycosaminoglycan synthesis) involved in growth. Our results demonstrate that sufficiently large sample sizes can uncover rare and low-frequency variants of moderate-to-large effect associated with polygenic human phenotypes, and that these variants implicate relevant genes and pathways.

Biobanking in carotid artery disease: translation to clinical practice

Biobanking of atherosclerotic tissue samples has contributed to our understanding of vascular occlusive disease. The careful examination of atherosclerotic plaques derived during vascular surgery or autopsies helped shape our minds in understanding the underlying substrate of arterial thrombosis. This review will outline concepts of progression of atherosclerotic disease that have been based on descriptions of human plaque pathology. In addition, we will discuss the current shift in clinical presentation and underlying pathology of acute cerebral and coronary events that asks for a careful consideration of the currently widely applied description of the "vulnerable plaque". The shift in atherosclerotic plaque characteristics that associate with a thrombotic event reflects the treatment and risk factor management that has undergone major changes in recent times. These changes may influence the value of past biobanking efforts in the current era: many inferences are being made upon sample data from cohorts that have been assembled in previous decades while large shifts in patient demographics and disease substrates over time occurred raises the question if biomarkers validated in historical biobanks can be extrapolated to the current era. As an example of altering profiles of biomarkers in the last decade, a panel of twelve selected plasma proteins was measured in the Athero-express cohort, showing time-dependent trends in serum biomarkers over the last decade. These findings strengthen our hypothesis that the pathogenesis of cardiovascular disease (CVD) is changing and future biobanking is required to successfully keep track of the mechanisms involved in CVD pathogenesis today.

Evidence for periprocedural antiplatelet therapy, heparinization and bridging of coumarin therapy in carotid revascularization

Thromboembolism prevention is a crucial factor determining both the natural outcome and outcome of intervention of stenotic atherosclerotic carotid artery pathology. Roughly 80% of all natural course cerebral ischemic events are caused by thromboembolism, versus 20% due to hemodynamic insufficiency. The risk of periprocedural cerebral (micro-) thromboembolization during carotid revascularization is considered to be even higher, with a higher rate in carotid artery stenting (CAS) as compared to carotid endarterectomy (CEA). Guidelines on CEA and CAS are unanimous in advising perioperative continuation of antiplatelet therapy (APT) for all patients to prevent thromboembolization without specification of the type of APT. Recommendations on dual antiplatelet (DAPT) therapy are inconsistent. Bridging vitamin K antagonists (VKA) perioperative with unfractionated heparin (UFH) or low-molecular weight heparins (LMWHs) might not be necessary for CAS, while CEA-specific data is lacking. No data are available on the use and position of direct-acting oral anticoagulants (DOACs) for CEA or CAS. Guidelines on treatment of carotid artery disease currently do not provide information on perioperative heparinization. There are several monitoring tools to detect perioperative micro-embolic signals during intervention or new cerebral white matter lesions following CEA or CAS. Transcranial Doppler ultrasonography (TDU) and diffusion weighed imaging (DWI) might be used to assess these (secondary) outcome measurements. The use of platelet function testing (PFT) to tailor APT might contribute to finding the therapeutic place of stronger APT and new APT regimen. Periprocedural antiplatelet and anticoagulation therapy for carotid revascularization still lacks solid evidence and guidelines do not yet cover the full spectrum of anticoagulants and procedural steps. This review aims to cover and discuss the full spectrum of available antiplatelet and anticoagulant drugs and therapies available for thromboembolism prevention during all crucial steps of revascularization and specify the need to know topics to be addressed in future research.

Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population

Background:

Among patients with clinically manifest vascular disease, the risk of recurrent vascular events is likely to vary. We assessed the distribution of estimated 10-year risk of recurrent vascular events in a secondary prevention population. We also estimated the potential risk reduction and residual risk that can be achieved if patients reach guideline-recommended risk factor targets.

Methods:

The SMART score (Second Manifestations of Arterial Disease) for 10-year risk of myocardial infarction, stroke, or vascular death was applied to 6904 patients with vascular disease. The risk score was externally validated in 18 436 patients with various manifestations of vascular disease from the TNT (Treating to New Targets), IDEAL (Incremental Decrease in End Points Through Aggressive Lipid Lowering), SPARCL (Stroke Prevention by Aggressive Reduction in Cholesterol Levels), and CAPRIE (Clopidogrel Versus Aspirin in Patients at Risk of Ischemic Events) trials. The residual risk at guideline-recommended targets was estimated by applying relative risk reductions from meta-analyses to the estimated risk for targets for systolic blood pressure, low-density lipoprotein cholesterol, smoking, physical activity, and use of antithrombotic agents.

Results:

The external performance of the SMART risk score was reasonable, apart from overestimation of risk in patients with 10-year risk >40%. In patients with various manifestations of vascular disease, median 10-year risk of a recurrent major vascular event was 17% (interquartile range, 11%–28%), varying from <10% in 18% to >30% in 22% of the patients. If risk factors were at guideline-recommended targets, the residual 10-year risk would be <10% in 47% and >30% in 9% of the patients (median, 11%; interquartile range, 7%–17%).

Conclusions:

Among patients with vascular disease, there is very substantial variation in estimated 10-year risk of recurrent vascular events. If all modifiable risk factors were at guideline-recommended targets, half of the patients would have a 10-year risk <10%. These data suggest that even with optimal treatment, many patients with vascular disease will remain at >20% and even >30% 10-year risk, clearly delineating an area of substantial unmet medical need.

Optimal cut-off criteria for duplex ultrasound compared with computed tomography angiography for the diagnosis of restenosis in stented carotid arteries in the international carotid stenting study

Introduction

Previous studies that reported duplex-ultrasound cut-off criteria, based on blood velocity parameters, for the degree of stenosis in a stented carotid artery were either retrospective, or the reference test was carried out only when a patient was suspected of having restenosis at duplex ultrasound, which is likely to have resulted in verification bias. We performed a prospective study of diagnostic accuracy to find new blood velocity cut-offs in duplex ultrasound for in-stent restenosis.

Patients and methods

Stented patients within the international carotid stenting study were eligible. Patients had a carotid computed tomography angiography in addition to routine duplex ultrasound performed at a yearly follow-up. Duplex-ultrasound bloodflow velocity parameters were compared to the degree of stenosis on computed tomography angiography. The results were analysed using receiver-operating-characteristic curves.

Results

We included 103 patients in this study. On computed tomography angiography, 30 (29.1%) patients had a 30%-49% in-stent restenosis, 21 (20.4%) patients had 50%-69% in-stent restenosis and 5 (4.9%) patients a ≥70% in-stent restenosis. The cut-off value ≥50% stenosis was a peak systolic velocity of 125 cm/s (sensitivity: 63% (95% CI: 41-79), specificity: 83% (95% CI: 72-90)).

Discussion

This study provides a level 2b evidence for new cut-off values for in-stent restenosis. Unfortunately, we could not say anything about severe stenosis because of the low number of severe stenosis after one year.

Conclusions

The 125 cm/s cut-off value on duplex ultrasound is lower than found in previous studies and equal to unstented arteries. Duplex-ultrasound measurements made in stented carotid arteries should not be corrected for the presence of a stent when determining the degree of stenosis.