Assessment of coronary heart disease risk by combined analysis of coagulation factors

High plasma soluble thrombomodulin levels indicated poor prognosis of decompensated liver cirrhosis: a prospective cohort study

OBJECTIVE

Hepatic sinusoidal endothelial injury is a prominent characteristic of liver cirrhosis. We determined plasma soluble thrombomodulin (sTM) levels in cirrhosis patients to evaluate the relationship between vascular injury and long-term prognosis.

METHODS

A prospective single-center study was performed. The participants were followed up for every 6 months or until death or transplantation. A chemiluminescent enzyme immunoassay was used to establish a baseline sTM.

RESULTS

Among the 219 patients with decompensated liver cirrhosis, 53.42% were caused by hepatitis B and hepatitis C. Plasma sTM levels were much higher in cirrhosis than in healthy controls and increased parallel with Child-Pugh classification ( P < 0.01) and the amount of ascites ( P = 0.04). After adjusting for sex, age, international normalized ratio, bilirubin, and other potential factors, multivariate Cox regression revealed that per TU/ml elevation of plasma sTM causes an increase of 8% in mortality, and per-SD elevation of thrombomodulin causes a 53% increase in mortality. As the mortality rates in low (5.90-12.60 TU/ml) and medium (12.70-18.00 TU/ml) sTM levels were similar, so we chose the cutoff of 18.00 TU/ml to divide into two groups, and K-M analysis indicated that patients with sTM >18.0 TU/ml demonstrated an additional 2.01 times death risk (95% CI, 1.13-7.93; P = 0.01) than those with sTM ≤18.0 TU/ml.

CONCLUSION

Plasma sTM in cirrhosis was significantly increased in parallel with the severity of liver dysfunction. sTM elevation than 18 TU/ml indicated a poor prognosis of decompensated liver cirrhosis.

Thrombomodulin as a Physiological Modulator of Intravascular Injury

Thrombomodulin (TM), which is predominantly expressed on the endothelium, plays an important role in maintaining vascular homeostasis by regulating the coagulation system. Intravascular injury and inflammation are complicated physiological processes that are induced by injured endothelium-mediated pro-coagulant signaling, necrotic endothelial- and blood cell-derived damage-associated molecular patterns (DAMPs), and DAMP-mediated inflammation. During the hypercoagulable state after endothelial injury, TM is released into the intravascular space by proteolytic cleavage of the endothelium component. Recombinant TM (rTM) is clinically applied to patients with disseminated intravascular coagulation, resulting in protection from tissue injury. Recent studies have revealed that rTM functions as an inflammatory regulator beyond hemostasis through various molecular mechanisms. More specifically, rTM neutralizes DAMPs, including histones and high mobility group box 1 (HMGB1), suppresses excessive activation of the complement system, physiologically protects the endothelium, and influences both innate and acquired immunity. Neutrophil extracellular traps (NETs) promote immunothrombosis by orchestrating platelets to enclose infectious invaders as part of the innate immune system, but excessive immunothrombosis can cause intravascular injury. However, rTM can directly and indirectly regulate NET formation. Furthermore, rTM interacts with mediators of acquired immunity to resolve vascular inflammation. So far, rTM has shown good efficacy in suppressing inflammation in various experimental models, including thrombotic microangiopathy, sterile inflammatory disorders, autoimmune diseases, and sepsis. Thus, rTM has the potential to become a novel tool to regulate intravascular injury via pleiotropic effects.

Exploring traditional and nontraditional roles for thrombomodulin

Thrombomodulin (TM) is an integral component of a multimolecular system, localized primarily to the vascular endothelium, that integrates crucial biological processes and biochemical pathways, including those related to coagulation, innate immunity, inflammation, and cell proliferation. These are designed to protect the host from injury and promote healing. The “traditional” role of TM in hemostasis was determined with its discovery in the 1980s as a ligand for thrombin and a critical cofactor for the major natural anticoagulant protein C system and subsequently for thrombin-mediated activation of the thrombin activatable fibrinolysis inhibitor (also known as procarboxypeptidase B2). Studies in the past 2 decades are redefining TM as a molecule with many properties, exhibited via its multiple domains, through its interacting partners, complex regulated expression, and synthesis by cells other than the endothelium. In this report, we review some of the recently reported diverse properties of TM and how these may impact on our understanding of the pathogenesis of several diseases.

Proteomic Profiling for Cardiovascular Biomarker Discovery in Orthostatic Hypotension

Orthostatic hypotension (OH) has been linked with higher incidence of cardiovascular disease, but little is known about the mechanisms behind this association. We aimed to identify cardiovascular disease biomarkers associated with OH through a proteomic profiling approach. Seven hundred seventy-eight patients with unexplained syncope or orthostatic intolerance underwent head-up tilt test and supine blood samples. Of these, 220 met diagnostic criteria of OH, and 179 demonstrated normal hemodynamic response during head-up tilt test. Blood samples were analyzed by antibody-based Proximity Extension Assay technique simultaneously measuring 92 cardiovascular disease-related human protein biomarkers. The discovery algorithm was a sequential 2-step process of biomarker signature identification by supervised, multivariate, principal component analysis and verification by univariate ANOVA with Bonferroni correction. Patients with OH were older (67 versus 60 years; P<0.001) and more likely to be women (48% versus 41%; P>0.001) but did not differ from OH-negative patients in medical history. Principal component analysis identified MMP-7 (matrix metalloproteinase-7), TM (thrombomodulin), MB (myoglobin), TIM-1 (T-cell immunoglobulin and mucin domain-1), CASP-8 (caspase-8), CXCL-1 (C-X-C motif chemokine-1), Dkk-1 (dickkopf-related protein-1), lectin-like LOX-1 (oxidized low-density lipoprotein receptor-1), PlGF (placenta growth factor), PAR-1 (proteinase-activated receptor-1), and MCP-1 (monocyte chemotactic protein-1) as the most robust proteomic signature for OH. From this proteomic feature selection, MMP-7 and TIM-1 met Bonferroni-adjusted significance criteria in univariate and multivariate regression analyses. Proteomic profiling in OH reveals a biomarker signature of atherothrombosis and inflammation. Circulating levels of MMP-7 and TIM-1 are independently associated with OH and may be involved in cardiovascular disease promotion.

Causal Effect of Plasminogen Activator Inhibitor Type 1 on Coronary Heart Disease

Background

Plasminogen activator inhibitor type 1 (PAI‐1) plays an essential role in the fibrinolysis system and thrombosis. Population studies have reported that blood PAI‐1 levels are associated with increased risk of coronary heart disease (CHD). However, it is unclear whether the association reflects a causal influence of PAI‐1 on CHD risk.

Methods and Results

To evaluate the association between PAI‐1 and CHD, we applied a 3‐step strategy. First, we investigated the observational association between PAI‐1 and CHD incidence using a systematic review based on a literature search for PAI‐1 and CHD studies. Second, we explored the causal association between PAI‐1 and CHD using a Mendelian randomization approach using summary statistics from large genome‐wide association studies. Finally, we explored the causal effect of PAI‐1 on cardiovascular risk factors including metabolic and subclinical atherosclerosis measures. In the systematic meta‐analysis, the highest quantile of blood PAI‐1 level was associated with higher CHD risk comparing with the lowest quantile (odds ratio=2.17; 95% CI: 1.53, 3.07) in an age‐ and sex‐adjusted model. The effect size was reduced in studies using a multivariable‐adjusted model (odds ratio=1.46; 95% CI: 1.13, 1.88). The Mendelian randomization analyses suggested a causal effect of increased PAI‐1 level on CHD risk (odds ratio=1.22 per unit increase of log‐transformed PAI‐1; 95% CI: 1.01, 1.47). In addition, we also detected a causal effect of PAI‐1 on elevating blood glucose and high‐density lipoprotein cholesterol.

Conclusions

Our study indicates a causal effect of elevated PAI‐1 level on CHD risk, which may be mediated by glucose dysfunction.

Thrombomodulin and the vascular endothelium: insights into functional, regulatory, and therapeutic aspects

Thrombomodulin (TM) is a 557-amino acid protein with a broad cell and tissue distribution consistent with its wide-ranging physiological roles. When expressed on the lumenal surface of vascular endothelial cells in both large vessels and capillaries, its primary function is to mediate endothelial thromboresistance. The complete integral membrane-bound protein form displays five distinct functional domains, although shorter soluble (functional) variants comprising the extracellular domains have also been reported in fluids such as serum and urine. TM-mediated binding of thrombin is known to enhance the specificity of the latter serine protease toward both protein C and thrombin activatable fibrinolysis inhibitor (TAFI), increasing their proteolytic activation rate by almost three orders of magnitude with concomitant anticoagulant, antifibrinolytic, and anti-inflammatory benefits to the vascular wall. Recent years have seen an abundance of research into the cellular mechanisms governing endothelial TM production, processing, and regulation (including flow-mediated mechanoregulation)--from transcriptional and posttranscriptional (miRNA) regulation of TM gene expression, to posttranslational processing and release of the expressed protein--facilitating greater exploitation of its therapeutic potential. The goal of the present paper is to comprehensively review the endothelial/TM system from these regulatory perspectives and draw some fresh conclusions. This paper will conclude with a timely examination of the current status of TM's growing therapeutic appeal, from novel strategies to improve the clinical efficacy of recombinant TM analogs for resolution of vascular disorders such as disseminated intravascular coagulation (DIC), to an examination of the complex pleiotropic relationship between statin treatment and TM expression.

Hemoconcentration and hemostasis during acute stress: interacting and independent effects

BACKGROUND

Acute psychological stress can produce significant hemoconcentration as well as prothrombotic changes in blood, both of which may have potentially harmful effects on the cardiovascular system. It is unclear whether these effects are independent or have influence on each other.

PURPOSE

This review discusses research investigating the effects of acute psychological stress on hemoconcentration and hemostasis and explores future directions for psychohematology research. Physiology, associations with cardiovascular disease, and relationships between acute psychological stress are discussed independently for hemoconcentration and hemostasis, followed by an examination of the effects of stress-hemoconcentration on hemostasis.

CONCLUSIONS

Traditional methods of adjusting for stress-hemoconcentration effects (e.g., calculated plasma volume or hematocrit level corrections) may not be appropriate when examining stress-induced changes in hemostasis. The effects of acute stress on hemostasis should be examined in conjunction with hemoconcentration.

Significant associations among hemostatic parameters, adipokines, and components of the metabolic syndrome in Japanese preschool children

Development of cardiovascular diseases could originate in early childhood. However, reference values of hemostatic parameters and adipokines in preschool children remain to be explored. We measured blood levels of adipokines and parameters of the hemostatic/fibrinolytic systems in 167 healthy children aged 4 to 6 years at 9:00 to 10:30 am after a strictly enforced overnight fast. Participants with body mass index (BMI) values ≥90th percentile had significantly higher values of systolic blood pressure and heart rate, as well as blood levels of insulin, coagulation factor (F) VII, FX, protein S, leptin, and homeostasis model assessment of insulin resistance (HOMA-IR), and lower values of desacyl-ghrelin than children with BMI < 90th percentile. Circulating levels of fibrinogen and leptin increased with increased number of cardiovascular risk factors. Stepwise regression analysis identified many hematological variables to be associated with features of the metabolic syndrome. The results implicated the hemostatic/fibrinolytic system or adipokines in the insidious progression of cardiovascular diseases from an early age.

Body Mass Index and Risk of Stroke and Myocardial Infarction in a Relatively Lean Population

Background–

The association of overweight/obesity with the incidence of cardiovascular diseases, especially stroke, has not been comprehensively examined in relatively lean populations in which stroke is more prevalent than coronary heart disease.

Methods and Results–

Pooled individual data from 16 Japanese cohorts comprising 45 235 participants ages 40 to 89 years without previous history of cardiovascular disease were studied. During follow-up, 1113 incident strokes and 190 myocardial infarctions were identified. At baseline, mean ages of men and women were 55.4 and 56.5 years and mean body mass indices (BMI) were 23.0 and 23.4 kg/m 2 , respectively. Compared with those with BMI <21.0, incidence rates of cerebral infarction in subjects with BMI ≥27.5 were significantly elevated in both men (hazard ratio, 1.81; 95% confidence interval [CI], 1.28 to 2.56) and women (hazard ratio, 1.65; 95% CI, 1.23 to 2.21), adjusted for age, smoking, and drinking habit. Incidence of cerebral hemorrhage was also associated positively with BMI in both men (hazard ratio, 2.51; 95% CI, 1.21 to 5.20) and women (hazard ratio, 1.98; 95% CI, 1.12 to 3.52). Adjustment for systolic blood pressure, a mediating factor, significantly attenuated most BMI association with stroke in both sexes. For myocardial infarction, the hazard ratio was 3.16 (95% CI, 1.66 to 6.01) for BMI 27.5 or greater versus less than 21.0 only in men, which appeared partly mediated by total cholesterol and SBP.

Conclusions–

Overweight/obesity was associated with an increased risk of cerebral infarction and hemorrhage in men and women and myocardial infarction in men. Weight control may have the potential to prevent both stroke and myocardial infarction in Japan.

Food intake patterns associated with carotid artery atherosclerosis in the Insulin Resistance Atherosclerosis Study

We aimed to identify food intake patterns that operate via haemostatic and inflammatory pathways on progression of atherosclerosis among 802 middle-aged adults with baseline and 5-year follow-up ultrasound measurements of common (CCA) and internal carotid artery (ICA) intimal medial thickness (IMT). Food intake was ascertained with an FFQ. We derived food patterns using reduced rank regression (RRR) with plasminogen activator inhibitor 1 and fibrinogen as response variables. We explored the impact of various food pattern simplification approaches. We identified a food pattern characterised by higher intakes of less healthful foods (low-fibre bread and cereal, red and processed meat, cottage cheese, tomato foods, regular soft drinks and sweetened beverages) and lower intakes of more healthful foods (wine, rice and pasta, meal replacements and poultry). The pattern was positively associated with mean CCA IMT at follow-up (P = 0.0032), a 1 sd increase corresponding to an increase of 13 mum higher CCA IMT at follow-up, adjusted for demographic and cardiovascular risk factors. With increasing pattern quartile (Q), the percentage change in CCA IMT increased significantly: Q1 0.8 %; Q2 3.2 %; Q3 8.6 %; Q4 7.9 % (P = 0.0045). No clear association with ICA IMT was observed. All simplification methods yielded similar results. The present results support the contention that a pro-inflammatory and pro-thrombotic dietary pattern increases the rate of coronary artery atherosclerosis progression, independent of traditional cardiovascular risk factors. RRR is a promising and robust tool for moving beyond the previous focus on nutrients or foods into research on the health effects of broader dietary patterns.