D-dimers in relation to the severity of arteriosclerosis in patients with stable angina pectoris after myocardial infarction

Clinical Impact of Thrombus Aspiration and Interaction With D-Dimer Levels in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Objectives: To evaluate the effect of thrombus aspiration (TA) strategy on the outcomes and its interaction with D-dimer levels in patients with ST-segment elevation myocardial infarction (STEMI) during primary percutaneous coronary intervention (PCI) in "real-world" settings. Materials and Methods: This study included 1,295 patients with STEMI who had undergone primary PCI with or without TA between January 2013 and June 2017. Patients were first divided into a TA+PCI group and a PCI-only group, and the baseline characteristics and long-term mortality between the two groups were analyzed. Furthermore, we studied the effect of TA on the clinical outcomes of patients grouped according to quartiles of respective D-dimer levels. The primary outcome was all-cause mortality, and the secondary outcomes were new-onset heart failure (HF), rehospitalization, re-PCI, and stroke. Results: In the original cohort, there were no significant differences in all-cause mortality between the TA+PCI and PCI-only groups (hazard ratio, 0.789; 95% confidence interval, 0.556-1.120; p = 0.185). After a mean follow-up of 2.5 years, the all-cause mortality rates of patients in the TA + PCI and PCI-only groups were 8.5 and 16.2%, respectively. Additionally, differences between the two groups in terms of the risk of HF, re-PCI, rehospitalization, and stroke were non-significant. However, after dividing into quartiles, as the D-dimer levels increased, the all-cause mortality rate in the PCI group gradually increased (4.3 vs. 6.0 vs. 7.0 vs. 14.7%, p < 0.001), while the death rate in the TA+PCI group did not significantly differ (4.6 vs. 5.0 vs. 4.0 vs. 3.75%, p = 0.85). Besides, in the quartile 3 (Q3) and quartile 4 (Q4) groups, the PCI-only group was associated with a higher risk of all-cause mortality than that of the TA+PCI group (Q3: 4.0 vs. 7.0%, p = 0.029; Q4: 3.75 vs. 14.7%, p < 0.001). Moreover, the multivariate logistic regression analysis demonstrated that TA is inversely associated with the primary outcome in the Q4 group [odds ratio (OR), 0.395; 95% CI, 0.164-0.949; p = 0.038]. Conclusions: The findings of our real-world study express that routine manual TA during PCI in STEMI did not improve clinical outcomes overall. However, patients with STEMI with a higher concentration of D-dimer might benefit from the use of TA during primary PCI. Large-scale studies are recommended to confirm the efficacy of TA.

Dietary Supplementation with Selenium and Coenzyme Q10 Prevents Increase in Plasma D-Dimer While Lowering Cardiovascular Mortality in an Elderly Swedish Population

A low intake of selenium is associated with increased cardiovascular mortality. This could be reduced by supplementation with selenium and coenzyme Q₁₀. D-dimer, a fragment of fibrin mirroring fibrinolysis, is a biomarker of thromboembolism, increased inflammation, endothelial dysfunction and is associated with cardiovascular mortality in ischemic heart disease. The objective was to examine the impact of selenium and coenzyme Q₁₀ on the level of D-dimer, and its relationship to cardiovascular mortality. D-dimer was measured in 213 individuals at the start and after 48 months of a randomised double-blind placebo-controlled trial with selenium yeast (200 µg/day) and coenzyme Q₁₀ (200 mg/day) (n = 106) or placebo (n = 107). The follow-up time was 4.9 years. All included individuals were low in selenium (mean 67 μg/L, SD 16.8). The differences in D-dimer concentration were evaluated by the use of T-tests, repeated measures of variance and ANCOVA analyses. At the end, a significantly lower D-dimer concentration was observed in the active treatment group in comparison with those on placebo (p = 0.006). Although D-dimer values at baseline were weakly associated with high-sensitive CRP, while being more strongly associated with soluble tumour necrosis factor receptor 1 and sP-selectin, controlling for these in the analysis there was an independent effect on D-dimer. In participants with a D-dimer level above median at baseline, the supplementation resulted in significantly lower cardiovascular mortality compared to those on placebo (p = 0.014). All results were validated with a persisting significant difference between the two groups. Therefore, supplementation with selenium and coenzyme Q₁₀ in a group of elderly low in selenium and coenzyme Q₁₀ prevented an increase in D-dimer and reduced the risk of cardiovascular mortality in comparison with the placebo group. The obtained results also illustrate important associations between inflammation, endothelial function and cardiovascular risk.

Gender-Specific Predictive Markers of Poor Prognosis for Patients with Acute Myocardial Infarction During a 6-Month Follow-up

Mounting evidence indicates the impact of gender difference on the assessment, treatment, and outcome of patients with acute myocardial infarction (AMI). However, gender-specific prognostic markers of AMI are still lacking. The present study aimed to investigate gender-specific markers of poor prognosis (all-cause mortality or readmission) in a cohort of AMI patients followed up for 6 months. Compared with males (n = 157), females (n = 40) were older and more frequent with previous medical history of hypertension and diabetes mellitus. During the 6-month follow-up, BUN ≥ 7.73 mM, myoglobin ≥ 705.8 ng/mL, and Killip classification 2-4 were identified as the independent predictors of poor prognosis for male AMI patients, while D-dimer ≥ 0.43 mg/L as an independent predictor of poor prognosis in female AMI patients. In conclusion, our data suggest that prognostic markers for AMI patients may differ according to genders. Gender-specific prognostic markers may be useful to guide the risk stratification, clinical therapy, and medications for AMI patients.

The utility of coagulation activity for prediction of risk of mortality and cardiovascular events in guideline-treated myocardial infarction patients

BACKGROUND

Despite improved treatment of myocardial infarction (MI), real-world patients still suffer substantial risk for subsequent cardiovascular events. Little is known about coagulation activity shortly after MI and whether coagulation activity markers may identify patients at increased risk despite contemporary treatment.

OBJECTIVE

To evaluate D-dimer concentration and thrombin generation potential shortly after discharge after MI and evaluate if these markers could predict the risk of future cardiovascular and bleeding events.

METHODS

Unselected MI patients (n = 421) were included in the observational REBUS study (NCT01102933) and followed for two years. D-dimer concentrations, thrombin peak, and endogenous thrombin potential (ETP) were analyzed at inclusion (3-5 days after MI) and at early follow-up (after 2-3 weeks).

RESULTS

Seventy-five patients (17.8%) experienced the composite endpoint (all-cause death, MI, congestive heart failure, or all-cause stroke), and 31 patients (7.4%) experienced a clinically relevant bleeding event. D-dimer concentrations at early follow-up were associated with the composite endpoint (HR [per SD increase] 1.51 [95% CI 1.22-1.87]) and with clinically relevant bleeding (HR [per SD increase] 1.80 [95% CI 1.32-2.44]). Thrombin generation potential was not significantly associated with either the composite endpoint or with clinically relevant bleeding. Higher thrombin peak and ETP at early follow-up were both inversely associated with stroke (HR [per SD increase] 0.50 [95% CI 0.30-0.81] and 0.43 [95% CI 0.22-0.83], respectively).

CONCLUSION

In unselected MI patients treated according to contemporary guidelines, D-dimer measurements may identify patients at increased risk of new cardiovascular and bleeding events. The inverse association of thrombin generation potential and risk of stroke has to be further investigated.

How to use D-dimer in acute cardiovascular care

D-dimer testing is important to aid in the exclusion of venous thromboembolic events (VTEs), including deep venous thrombosis and pulmonary embolism, and it may be used to evaluate suspected aortic dissection. D-dimer is produced upon activation of the coagulation system with the generation and subsequent degradation of cross-linked fibrin by plasmin. Many different assays for D-dimer testing are currently used in routine care. However, these tests are neither standardized nor harmonized. Consequently, only clinically validated assays and assay specific decision limits should be used for routine testing. For the exclusion of pulmonary embolism/deep vein thrombosis, age-adjusted cut-offs are recommend. Clinicians must be aware of the validated use of their hospital's D-dimer assay to avoid inappropriate use of this biomarker in routine care.

RVX-208, a BET-inhibitor for treating atherosclerotic cardiovascular disease, raises ApoA-I/HDL and represses pathways that contribute to cardiovascular disease

High density lipoproteins (HDL), through activity of the main protein component apolipoprotein A-I (ApoA-I), can reduce the risk of cardiovascular disease (CVD) by removing excess cholesterol from atherosclerotic plaque. In this study, we demonstrate that the bromodomain and extraterminal domain (BET) inhibitor RVX-208 increases ApoA-I gene transcription and protein production in human and primate primary hepatocytes. Accordingly, RVX-208 also significantly increases levels of ApoA-I, HDL-associated cholesterol, and HDL particle number in patients who received the compound in recently completed phase 2b trials SUSTAIN and ASSURE. Moreover, a post-hoc analysis showed lower instances of major adverse cardiac events in patients receiving RVX-208. To understand the effects of RVX-208 on biological processes underlying cardiovascular risk, we performed microarray analyses of human primary hepatocytes and whole blood treated ex vivo. Overall, data showed that RVX-208 raises ApoA-I/HDL and represses pro-inflammatory, pro-atherosclerotic and pro-thrombotic pathways that can contribute to CVD risk.

Differential cellular effects of old and new oral anticoagulants: consequences to the genesis and progression of atherosclerosis

The main purpose of anticoagulants is to diminish fibrin formation, thereby decreasing the risk of venous or arterial thrombosis. Vitamin K antagonist have been used for many decades in order to achieve reduced thrombotic risk, despite major drawbacks of this class of drugs such as cumbersome dossing and monitoring of anticoagulant status. To overcome these drawbacks of VKA, new classes of anticoagulants have been developed including oral anticoagulants for direct inhibition of either thrombin or factor Xa, which can be administrated in a fixed dose without monitoring. Coagulation factors can activate cellular protease-activated receptors, thereby inducing cellular processes as inflammation, apoptosis, migration, and fibrosis. Therefore, inhibition of coagulation proteases not only attenuates fibrin formation, but may also influence pathophysiological processes like vascular calcification and atherosclerosis. Animal models revealed that VKA therapy induced both intima and media calcification and accelerated plaque vulnerability, whereas specific and direct inhibition of thrombin or factor Xa attenuated atherosclerosis. In this review we provide an overview of old and new oral anticoagulants, as well discuss potential pleiotropic effects with regard to calcification and atherosclerosis. Although translation from animal model to clinical patients seems difficult at first sight, effort should be made to fully understand the clinical implications of long-term oral anticoagulant therapy on vascular side effects.

RISK OF RECURRENT THROMBOTIC EVENTS IN PATIENTS WITH ACUTE CORONARY SYNDROME AND HIGH PLASMA LEVELS OF D-DIMER

Aim. To study the association of plasma D-dimer levels and the risk of thrombotic events in patients hospitalised with acute coronary syndrome (ACS).

Material and methods. The study included 70 patients, aged 34-88 years, who were admitted to the Acute Coronary Care Unit with the ACS diagnosis.

Results. During the follow-up period, thrombotic events were registered in 12 patients (17%). Three patients with myocardial infarction (MI) suffered recurrent MI. Nine patients were rehospitalised with the unstable angina (UA) diagnosis. All participants were divided into quartiles by the levels of D-dimer (25% percentile 136 ng/ml; median 1250 ng/ml; and 75% percentile 2930 ng/ml). High plasma levels of D-dimer (third quartile) were associated with a 1,5-fold increase in the risk of recurrent thrombotic events among ACS patients.

Conclusion. In ACS patients, plasma D-dimer levels could be regarded as one of the additional risk factors of thrombotic events. 

D-dimer as a marker for cardiovascular and arterial thrombotic events in patients with peripheral arterial disease. A systematic review

Peripheral artery disease (PAD) is associated with an increased risk for cardiovascular events. D-dimers are a marker for hypercoagulability and are linked with thrombotic events in patients with venous as well as arterial thrombosis. The predictive value of plasma D-dimer levels in relation to cardiovascular events in patients with PAD is not unambiguously established. It was our objective to gather evidence evaluating the value of D-dimer as a predictor of arterial thrombotic events patients with PAD. The Pubmed, Embase, and Cochrane databases were searched (January 1980-November 2012), and 65 abstracts were found. The strategy was supplemented with manual review of reference lists. Case-control, cohort or prospective cohort studies that measured fibrin D-dimer in patients with PAD, were included. Studies were excluded if there was no follow-up for arterial thrombotic events or when no specific information on D-dimer was available. The search yielded 10 studies for our analysis, comprising 2,420 patients with PAD, with a total of 1,036 cardiovascular events in 10,599 patient-years. Two studies with a follow-up of one year showed that fibrin D-dimer predicts both deterioration of PAD and subsequent thrombotic events. Five out of six studies with a median follow-up of 2-4 years revealed that an increased D-dimer is predictive of various arterial thrombotic events including mortality. Two studies with a longer follow-up (over 6 years) did not show an independent association between increased D-dimer levels, arterial thrombotic events and CVD mortality. In conclusion, an increased D-dimer appeared to be independently associated with a two times increased risk of near-term cardiovascular events (relative risk 2.30, 95% confidence interval 1.43-3.68). However formal meta-analysis was only feasible for four out of 10 included studies. Due to the extended heterogeneity of the included studies cautious interpretation of these data is warranted.

Aggregate risk score based on markers of inflammation, cell stress, and coagulation is an independent predictor of adverse cardiovascular outcomes

OBJECTIVES

This study sought to determine an aggregate, pathway-specific risk score for enhanced prediction of death and myocardial infarction (MI).

BACKGROUND

Activation of inflammatory, coagulation, and cellular stress pathways contribute to atherosclerotic plaque rupture. We hypothesized that an aggregate risk score comprised of biomarkers involved in these different pathways-high-sensitivity C-reactive protein (CRP), fibrin degradation products (FDP), and heat shock protein 70 (HSP70) levels-would be a powerful predictor of death and MI.

METHODS

Serum levels of CRP, FDP, and HSP70 were measured in 3,415 consecutive patients with suspected or confirmed coronary artery disease (CAD) undergoing cardiac catheterization. Survival analyses were performed with models adjusted for established risk factors.

RESULTS

Median follow-up was 2.3 years. Hazard ratios (HRs) for all-cause death and MI based on cutpoints were as follows: CRP ≥3.0 mg/l, HR: 1.61; HSP70 >0.625 ng/ml, HR; 2.26; and FDP ≥1.0 μg/ml, HR: 1.62 (p < 0.0001 for all). An aggregate biomarker score between 0 and 3 was calculated based on these cutpoints. Compared with the group with a 0 score, HRs for all-cause death and MI were 1.83, 3.46, and 4.99 for those with scores of 1, 2, and 3, respectively (p for each: <0.001). Annual event rates were 16.3% for the 4.2% of patients with a score of 3 compared with 2.4% in 36.4% of patients with a score of 0. The C statistic and net reclassification improved (p < 0.0001) with the addition of the biomarker score.

CONCLUSIONS

An aggregate score based on serum levels of CRP, FDP, and HSP70 is a predictor of future risk of death and MI in patients with suspected or known CAD.

Elevated plasma D-dimer and hypersensitive C-reactive protein levels may indicate aortic disorders

OBJECTIVE

D-dimer and C-reactive protein are of diagnostic and predictive values in patients have thrombotic tendency, such as vascular thrombosis, coronary artery disease and aortic dissection. However, the comparative study in these biomarkers between the patients with acute aortic dissection and coronary artery disease has not been sufficiently elucidated.

METHODS

Consecutive surgical patients for acute type A aortic dissection (20 patients), aortic aneurysm (nine patients) or coronary artery disease (20 patients) were selected into this study. Plasma from preoperative blood samples and supernatant of aortic homogenate of the surgical specimens were detected for D-dimer and hypersensitive C-reactive protein (hs-CRP).

RESULTS

Plasma D-dimer and hs-CRP values in type A aortic dissection or aortic aneurysm were much higher than in coronary artery disease patients or the healthy control (for D-dimer, aortic dissection: coronary artery disease, 0.4344 ± 0.2958 µg/ml vs. 0.0512 ± 0.0845 µg/ml, P < 0.0001; aortic dissection: healthy control, 0.4344 ± 0.2958 µg/ml vs. 0.1250 ± 0.1295 µg/ml, P = 0.0005; aortic aneurysm: coronary artery disease, 0.4200 ± 0.4039 µg/ml vs. 0.0512 ± 0.0845 µg/ml, P = 0.0013; and aortic aneurysm: healthy control, 0.4200 ± 0.4039 µg/ml vs. 0.1250 ± 0.1295 µg/ml, P = 0.0068; and for hs-CRP, aortic dissection: coronary artery disease, 4.400± 3.004 mg/L vs. 1.232±0.601 mg/L, P < 0.0001; aortic dissection:healthy control, 4.400 ± 3.004 mg/L vs. 0.790 ± 0.423 mg/L, P < 0.0001; aortic aneurysm: coronary artery disease, 2.314 ± 1.399 mg/L vs. 1.232 ± 0.601 mg/L, P = 0.0084; aortic aneurysm: healthy control, 2.314 ± 1.399 mg/L vs. 0.790 ± 0.423 mg/L, P = 0.0002; and coronary artery disease: healthy control, 1.232 ± 0.601 mg/L vs. 0.790 ± 0.423 mg/L, P = 0.0113). Besides, there were close correlations between plasma D-dimer and hs-CRP in overall (Y = 4.8798X + 0.8138, r² = 0.4497, r = 0.671, P < 0.001), aortic dissection (Y = 2.6298X + 1.2098, r² = 0.5762, r = 0.759, P < 0.001), and aortic aneurysm (Y = 7.1341X + 1.3006, r² = 0.4935, r = 0.7025, P = 0.048) groups rather than in the coronary artery disease or healthy control subjects. In addition, there were no significant differences between D-dimer and hs-CRP values of the aortic supernatant among groups except for undetectable D-dimer in the aortic supernatant of the coronary artery disease group.

CONCLUSIONS

The patients with acute aortic dissection and aortic aneurysm may reflect the extensive inflammatory reaction and severe coagulopathies in the patients with acute type A aortic dissection, and thoracic aortic aneurysm in comparison to the coronary patients and healthy control individuals. The detections after onset in the patients with acute chest pain may help making a differential diagnosis between the aortopathies and ischemic heart disease. The scanty significance of the tissue biomarkers may preclude their diagnostic value in clinical practice.

The impact of blood coagulability on atherosclerosis and cardiovascular disease

Although the link between blood coagulation and atherogenesis has been long postulated, only recently, and through the extensive work on transgenic mice, crossbred on an atherogenic background, has the direction of this interaction become visible. In general, hypercoagulability in mice tends to increase atherosclerosis, whereas hypocoagulability reduces the atherosclerotic burden, depending on the mouse model used. The information on a direct relationship between coagulation and atherosclerosis in humans, however, is not that clear. Almost all coagulation proteins, including tissue factor, are found in atherosclerotic lesions in humans. In addition to producing local fibrin, a matrix for cell growth, serine proteases such as thrombin may be very important in cell signaling processes, acting through the activation of protease-activated receptors (PARs). Activation of PARs on vascular cells drives many complex processes involved in the development and progression of atherosclerosis, including inflammation, angiogenesis, and cell proliferation. Although current imaging techniques do not allow for a detailed analysis of atherosclerotic lesion phenotype, hypercoagulability, defined either by gene defects of coagulation proteins or elevated levels of circulating markers of activated coagulation, has been linked to atherosclerosis-related ischemic arterial disease. New, high-resolution imaging techniques and sensitive markers of activated coagulation are needed in order to study a causal contribution of hypercoagulability to the pathophysiology of atherosclerosis. Novel selective inhibitors of coagulation enzymes potentially have vascular effects, including inhibition of atherogenesis through attenuation of inflammatory pathways. Therefore, we propose that studying the long-term vascular side effects of this novel class of oral anticoagulants should become a clinical research priority.

Associations of D-dimer and von Willebrand factor with atherosclerosis in Japanese and white men

OBJECTIVE

D-dimer and von Willebrand factor (vWF) are associated with atherosclerosis. We recently reported that in a post-World War II birth cohort, Japanese men in Japan had lower levels of atherosclerosis than white men in the United States (U.S.). We examined whether the differences in D-dimer and vWF levels are associated with differences in atherosclerosis between the two populations.

METHODS AND RESULTS

Population-based samples of 99 Japanese and 100 white American men aged 40-49 years were examined for coronary artery calcification (CAC), carotid intima-media thickness (IMT), D-dimer, vWF, and other factors using a standardized protocol. When compared to white American men,Japanese had similar levels of D-dimer (0.22 +/- 0.28 vs. 0.19 +/- 0.24 microg/L, respectively, P = 0.39) but significantly higher levels of vWF (124.1 +/- 36.6 vs. 91.3 +/- 48.8%, respectively, P < 0.01). Japanese as compared to white American men had significantly lower prevalence of CAC (13.1 vs. 28.0%, P < 0.01, respectively) and significantly lower IMT (0.61 +/- 0.07 vs. 0.66 +/- 0.08 mm, P < 0.01, respectively). Japanese men had a significant positive association of D-dimer with the prevalence of CAC and a negative association of vWF with IMT, whereas white American men did not have any significant associations.

CONCLUSIONS

In men aged 40-49 years, Japanese as compared to white Americans had similar levels of D-dimer and higher levels of vWF although Japanese had a significantly lower prevalence of CAC and IMT. These haemostatic factors are unlikely to explain the difference in atherosclerosis in these populations.

Significance of plasma D-dimer in relation to the severity of atherosclerosis among patients evaluated by non-invasive indices of cardio-ankle vascular index and carotid intima-media thickness

The aim of this study is to elucidate the usefulness of plasma D-dimer for the prediction of thrombotic events in highly atherosclerotic patients. The severity of atherosclerosis was measured by non-invasive methods including cardio-ankle vascular index (CAVI) and carotid intima-media thickness (IMT) in 100 patients with atherosclerosis aged 72.1 years on average. CAVI was significantly correlated with the levels of D-dimer, platelet aggregation (Plt Aggre), uric acid (UA), creatinine (Cr), blood urea nitrogen (BUN), and C-reactive protein (CRP), whereas IMT was significantly correlated with the levels of Cr, BUN, and CRP. CAVI and IMT were suitable for stratification of the patients. A comparison of hemostatic markers (D-dimer, fibrinogen and Plt Aggre) between the less sclerotic group (group A; CAVI <8.0 and IMT <1.1 mm, n = 26) and the highly sclerotic group (group B; CAVI >8.0 and IMT >1.1 mm, n = 32) revealed that the incidence of thrombosis was significantly higher in group B (18.8%) than in group A (3.8%) and that D-dimer was significantly higher (p < 0.01, Mann-Whitney U test) in group B (0.48 mug/ml, median) than in group A (0.32 mug/ml, median). Moreover, multiple linear regression analyses of CAVI and IMT indicated that D-dimer and age were significant variables. In conclusion, D-dimer is significantly associated with thrombosis in highly atherosclerotic patients.

A multimarker risk stratification approach to non-ST elevation acute coronary syndrome: implications of troponin T, CRP, NT pro-BNP and fibrin D-dimer levels

INTRODUCTION

Biomarkers have emerged as interesting predictors of risk in non-ST elevation acute coronary syndromes (non-ST ACS). The aim of this study was to define the utility of the combined measurement of troponin T (TnT), C-reactive protein (CRP), NT pro-brain natriuretic peptide (NT pro-BNP) and D-dimer as biomarkers to predict adverse events.

METHODS

We included 358 consecutive patients admitted in two hospitals for non-ST ACS. Baseline measurements of TnT (associated with myocardial injury, positive, if > or =0.1 ng mL(-1)), CRP (a marker of inflammation), NT-proBNP (associated with left ventricular (dys)function) and fibrin D-dimer (and index of thrombogenesis) were performed. A positive CRP, NT-proBNP and D-dimer test was considered upper than the 75th percentile of our population. The risk for major events (death, new ACS, revascularization and heart failure) at 6 months' follow-up was analysed.

RESULTS

Troponin T, NT pro-BNP and CRP were predictors of adverse events in the multivariate analysis [hazards ratio (HR): 2.00 (1.30-3.07), P = 0.0016; HR: 2.27 (1.47-3.50), P = 0.0002; HR: 1.90 (1.24-2.92), P = 0.0034 respectively], but not D-dimer levels [HR: 1.26 (0.79-2.02), P = 0.337). After adjusting for baseline characteristics and electrocardiographic changes, multimarker risk approach was associated with adverse events at 6 months, especially with the presence of three positive biomarkers [HR 2.80 (95%CI 1.68-4.68), P < 0.001]. When we divided patients by risk groups [Thrombolysis in Myocardial Infarction (TIMI) risk score], patients with two or three elevated biomarkers had higher event rates [HR 2.59 (95% CI 1.37-4.91), P = 0.004].

CONCLUSION

A multimarker approach based on TnT, CRP and NT-proBNP provides added information to the TIMI risk score in terms of ACS prognosis at 6 months, with a worse outcome for those with two or three elevated biomarkers.

Fibrin D-dimer fragments enhance inflammatory responses in macrophages: role in advancing atherosclerosis

1. Fibrin D-dimer is considered a consistent and independent marker of the risk of cardiovascular disease in population studies, as well as being related to atherosclerosis severity in patients. However, the role of fibrin D-dimer in macrophage-derived foam cell formation during atherogenesis remains unclear. 2. In the present study, using microarray techniques, we determined the effects of 100 ng/mL fibrin D-dimer fragments on macrophage cell function in atherosclerosis by investigating the expression levels of 128 genes related to the atherosclerotic pathophysiological processes. 3. The results showed that 27 genes were enhanced by D-dimer fragments to over twofold of control. These 27 genes belonged to six groups and included adhesion molecules, extracellular molecules, molecules related to lipid transport and metabolism, cell growth and proliferation molecules, transcription regulators and genes responsive to stress. We proceeded to determine the expression levels of five of these genes (intercellular adhesion molecule-1, matrix metalloproteinase-9, oxidized low-density lipoprotein receptor 1, vascular endothelial growth factor A and peroxisome proliferator-activated receptor alpha) using SYBR real-time polymerase chain reaction. The results confirmed gene upregulation, similar to the results obtained with the microarray, following treatment with D-dimer. 4. Therefore, the present study provides direct evidence regarding the pro-atherosclerotic role of D-dimer in macrophage function, which is mainly to enhance the inflammatory response during macrophage-derived foam cell formation.

D-dimer local expression is increased in symptomatic patients undergoing carotid endarterectomy

BACKGROUND

Although atherosclerosis is a silent widespread disease, the focal character of the lesions triggering the clinical manifestations is unquestionable. We hypothesized that symptomatic patients with advanced, unstable carotid plaques have increased local intraplaque and circulating levels of fibrin-fibrinogen related products.

METHODS

Plaque tissue and plasma samples were studied in 106 patients undergoing endarterectomy for symptomatic and asymptomatic carotid disease. Fibrin-fibrinogen related products were evaluated by ELISA, Western-blotting, and histology. All tested parameters were compared with patient carotid symptomatology, multiple vascular risk factors (VRF), bilateral carotid pathology, ultrasound examination, and previous therapies with statins and/or antiplatelet drugs.

RESULTS

In symptomatic patients, plasma D-dimer was elevated in patients with unstable carotid plaques (UNS) compared with stable (STA) ones (857+/-121 vs. 692+/-156 ng/ml, p=0. 026). Furthermore, plasma D-dimer was significantly increased in patients with a coexistence of carotid and coronary artery disease, compared to others (976+/-325 vs. 714+/-197 ng/ml; p<0.001). Intra-plaque D-dimer content was increased in ulcerated-complicated (UC) plaques compared with fibrous non-complicated (F) plaques in symptomatic patients (5.9+/-1 vs. 1.8+/-1, p<0.001), and in patients with hypercholesterolaemia, compared with those with normal cholesterol levels (6.1+/-1 vs. 2.9+/-0.7; p=0.027). However, there was no correlation between D-dimer content in the carotid plaque and plasma D-dimer levels.

CONCLUSIONS

Hypercholesterolemia and UC plaques appear to be associated with high fibrin intraplaque turnover as demonstrated by higher intraplaque D-dimer. Plasma markers of fibrin turnover were increased in UNS plaques, and in patients with coexisting carotid and coronary artery disease. Although, both plasma and plaque D-dimers were associated with unstable carotid disease, the usefulness of the measurement of plasma D-dimer in these patients should be confirmed by prospective studies.

Fibrin(ogen) and its fragments in the pathophysiology and treatment of myocardial infarction

The occlusion of a coronary artery leads to ischemia of the myocardium, while permanent occlusion results in cell death and myocardial dysfunction. Early restoration of blood flow is the only means to reduce or prevent myocardial necrosis, but-paradoxically-reperfusion itself contributes to injury of the heart. In animal models, this phenomenon is well described, and there are many different unrelated approaches to reduce reperfusion injury. In humans, however, pharmacological interventions have so far failed to reduce myocardial reperfusion injury. We summarize the pathogenesis of reperfusion injury, detailing the role of fibrin(ogen) and its derivatives. Moreover, we introduce a new concept for fibrin derivatives as potential targets for reperfusion therapy.

Risk factors for concomitant peripheral arterial occlusive disease in patients with coronary artery disease: is there a difference between diabetic and non-diabetic patients?

AIM OF THE STUDY

The aim of the present study was investigation of cardiovascular risk factors for concomitant Peripheral Arterial Occlusive Disease (PAOD) in diabetic vs. non-diabetic patients with coronary artery disease (CAD).

PATIENTS AND METHODS

This study included 302 patients (229 men) with a mean age of 62.2 +/- 11.5 years and angiographically documented CAD. These were divided into Group A comprising 116 diabetic patients (79 men) and Group B comprising 186 non-diabetic patients (150 men). Peripheral Arterial Occlusive Disease (PAOD) was diagnosed using a Doppler apparatus. Cardiovascular risk factors that were investigated included age, history of myocardial infarction, smoking, Body-Mass Index, Waist-Hip-Ratio, hypertension and serum lipids.

RESULTS

PAOD was diagnosed in 49 patients of Group A (42.4%) and 20 patients of Group B (10.8%). In Group A concomitant PAOD was associated with significantly (p = 0.0001) longer diabetes duration and significantly (p = 0.0001) higher frequency of insulin treatment, as well as significantly (p = 0.02) higher triglycerides and significantly (p = 0.039) lower HDL-Cholesterol. In Group B patients with PAOD had significantly (p = 0.0001) higher age and significantly higher (p = 0.041) LDL-Cholesterol levels than those without PAOD. No association was found between PAOD and presence of remaining risk factors in either group. In multiple regression analysis, concomitant PAOD was associated with diabetes duration (p = 0.0026) and insulin treatment (p = 0.0004) in Group A, while it was associated with age (p = 0.01) in Group B. The associations with serum lipids were no longer significant.

CONCLUSIONS

Among non-diabetic patients with CAD, those who have concomitant PAOD are significantly older. Among diabetic patients with CAD, those who have concomitant PAOD show significantly longer diabetes duration and significantly higher frequency of insulin treatment.

Effects of intermittent fasting on serum lipid levels, coagulation status and plasma homocysteine levels

BACKGROUND

During Ramadan, Muslims fast during the daylight hours for a month. The duration of restricted food and beverage intake is approximately 12 h/day which makes Ramadan a unique model of intermittent fasting. Many physiological and psychological changes are observed during Ramadan that are probably due to the changes in eating and sleeping patterns.

METHODS

Serum total cholesterol, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), prothrombin time, activated partial thromboplastin time (aPTT), plasma fibrinogen, D-dimer and homocysteine levels were measured in 24 healthy fasting volunteers (12 females, 12 males) aged 21-35 years. Venous blood samples were taken 1 week before Ramadan, on the 21st day of Ramadan and 20 days after Ramadan.

RESULTS

No significant changes were observed on serum total cholesterol, triglycerides and LDL levels. HDL levels were significantly elevated during Ramadan (p < 0.001) and 20 days after Ramadan (p < 0.05). Prothrombin time, aPTT, fibrinogen and D-dimer levels were in the physiologic limits in all samples but D-dimer levels were significantly low at the end of Ramadan in comparison to pre- and post-fasting levels (p < 0.001). Homocysteine levels, being still in reference ranges, were low during Ramadan (p < 0.05) and reached the pre-fasting levels after Ramadan.

CONCLUSION

Our results demonstrate that intermittent fasting led to some beneficial changes in serum HDL and plasma homocysteine levels, and the coagulation status. These changes may be due to omitting at least one meal when the body was particularly metabolically active and possibly had a low blood viscosity level at the same time. We conclude that intermittent fasting may have beneficial effects on hemostatic risk markers for cardiovascular diseases.

Periodic acceleration: effects on vasoactive, fibrinolytic, and coagulation factors

Cellular and isolated vessel experiments have shown that pulsatile and laminar shear stress to the endothelium produces significant release of mediators into the circulation. Periodic acceleration (pGz) applied to the whole body in the direction of the spinal axis adds pulses to the circulation, thereby increasing pulsatile and shear stress to the endothelium that should also cause release of mediators into the circulation. The purpose of this study was to determine whether addition of pulses to the circulation through pGzwould be sufficient to increase shear stress in whole animals and to acutely release mediators and how such a physical maneuver might affect coagulation factors. Randomized control experiments were performed on anesthetized, supine piglets. The treatment group (pGz) ( n = 12) received pGzwith a motion platform that moved them repetitively head to foot at ±0.4 g at 180 cpm for 60 min. The control group ( n = 6) was secured to the platform but remained on conventional ventilation throughout the 4-h protocol. Compared with control animals and baseline, pulsatile stress produced significant increases of serum nitrite, prostacyclin, PGE2, and tissue plasminogen activator antigen and activity, as well as D-dimer. There were no significant changes in epinephrine, norepinephrine, cortisol, and coagulation factors between groups or from baseline values. Pulsatile and laminar shear stress to the endothelium induced by pGzsafely produces increases of vasoactive and fibrinolytic activity. pGzhas potential to achieve mediator-related benefits from the actions of nitric oxide and prostaglandins.

Peripheral arterial occlusive disease as a predictor of the extent of coronary atherosclerosis in patients with coronary artery disease with and without diabetes mellitus

We evaluated the sensitivity and specificity of a diagnosis of peripheral arterial occlusive disease (PAOD) as a predictor of the severity of coronary artery disease (CAD) in patients with and without diabetes. A total of 302 patients were assigned to groups according to the angiographic severity of their CAD and their diabetes status. Both PAOD and severe PAOD were diagnosed by measuring the ankle-brachial index (ABI) and toe-brachial index (TBI). A diagnosis of PAOD had a low sensitivity (34.3%) but a high specificity (87.0%) for detecting patients with severe CAD. Sensitivity was higher in patients with diabetes (52.4%) than without (19.5%), whereas specificity was higher in patients without diabetes (95.4%) than those with diabetes (69.8%). A diagnosis of severe PAOD had a higher specificity (96.0%), but a very low sensitivity (16.4%). We conclude that a diagnosis of PAOD among patients with CAD had a low sensitivity but a high specificity for detecting those with severe CAD, particularly in patients without diabetes.

Blood coagulation and the risk of atherothrombosis: a complex relationship

The principles of Virchov's triad appear to be operational in atherothrombosis or arterial thrombosis: local flow changes and particularly vacular wall damage are the main pathophysiological elements. Furthermore, alterations in arterial blood composition are also involved although the specific role and importance of blood coagulation is an ongoing matter of debate. In this review we provide support for the hypothesis that activated blood coagulation is an essential determinant of the risk of atherothrombotic complications. We distinguish two phases in atherosclerosis: In the first phase, atherosclerosis develops under influence of "classical" risk factors, i.e. both genetic and acquired forces. While fibrinogen/fibrin molecules participate in early plaque lesions, increased activity of systemic coagulation is of no major influence on the risk of arterial thrombosis, except in rare cases where a number of specific procoagulant forces collide. Despite the presence of tissue factor – factor VII complex it is unlikely that all fibrin in the atherosclerotic plaque is the direct result from local clotting activity. The dominant effect of coagulation in this phase is anticoagulant, i.e. thrombin enhances protein C activation through its binding to endothelial thrombomodulin.

The second phase is characterized by advancing atherosclerosis, with greater impact of inflammation as indicated by an elevated level of plasma C-reactive protein, the result of increased production influenced by interleukin-6. Inflammation overwhelms protective anticoagulant forces, which in itself may have become less efficient due to down regulation of thrombomodulin and endothelial cell protein C receptor (EPCR) expression. In this phase, the inflammatory drive leads to recurrent induction of tissue factor and assembly of catalytic complexes on aggregated cells and on microparticles, maintaining a certain level of thrombin production and fibrin formation. In advanced atherosclerosis systemic and vascular wall driven coagulation becomes more important and elevated levels of D-dimer fragments should be interpreted as markers of this hypercoagulability.

Soluble fibrin, C-reactive protein, fibrinogen, factor VII, antithrombin, proteins C and S, tissue factor, D-dimer, and prothrombin fragment 1 + 2 in men with acute myocardial infarction </=45 years of age

To evaluate the contribution of hematologic factors and long-term inflammation to the development of myocardial infarction at a young age, we measured hematologic variables, including soluble fibrin and high-sensitivity C-reactive protein, in 90 patients who had myocardial infarction and 138 controls </=45 years of age. Plasma levels of soluble fibrin and C-reactive protein were significantly higher in patients than in controls. On multivariate regression analysis, soluble fibrin was the strongest predictor of myocardial infarction at a young age.

Association between plasmin activation system and intravascular ultrasound signs of plaque instability in patients with unstable angina and non-st-segment elevation myocardial infarction

BACKGROUND

The association between intravascular ultrasound (IVUS) signs of plaque instability and plasma levels of biomarkers was determined in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI).

METHODS

Fifty-two patients underwent coronary angiography and IVUS 8 +/- 5 hours after the onset of chest pain. IVUS analysis included plaque morphology, disruption, thrombi and eccentricity, lumen, external elastic membrane, and plaque plus media areas of culprit lesion and reference segments and arterial remodeling. Plasma levels of the thrombin activation system (thrombin-antithrombin complex [TAT], tissue factor pathway inhibitor [TFPI], and prothrombin fragments 1+2 [F1+2]) and plasmin activation system (tissue and urokinase-type plasminogen activator [t-PA and u-PA], plasminogen activator inhibitor-1 [PAI-1], and D-dimer) were measured with enzyme-linked immunosorbent assay kits before angiography.

RESULTS

Elevated levels of TAT (7.2 +/- 6.0 microg/L), F1+2 (1.8 +/- 1.0 nmol/L), TFPI (179.1 +/- 131.0 ng/mL), PAI-1 (95.4 +/- 54.6 ng/mL), t-PA (10.6 +/- 8.8 ng/mL), and u-PA (2.6 +/- 0.9 ng/mL) were found in patients with UA/NSTEMI. The serum levels of D-dimer (40.0 +/- 39.5 ng/mL) remained in reference range. Expansive and constrictive remodeling were found in 18 (35%) and 12 (23%) patients, respectively. Expansive remodeling of the culprit lesion was associated with significantly higher plasma levels of PAI-1 (121.6 +/- 55.0 vs 87.7 +/- 61.5 and 77.4 +/- 42.8 ng/ml, P =.039), and u-PA (3.0 +/- 1.2 vs 2.2 +/- 0.5 and 2.5 +/- 0.7 ng/mL, P =.026) as compared with constrictive and neutral remodeling. Increased plasma levels of u-PA were associated with plaque rupture (3.0 +/- 0.7 vs 2.5 +/- 0.9 ng/mL, P =.062). Plasma levels of PAI-1 and u-PA correlated positively with plaque plus media (P =.0297 and P =.0093) and external elastic membrane areas (P =.010 and P =.0002).

CONCLUSIONS

Elevated levels of biomarkers of plasmin activation system are associated with signs of plaque instability of culprit lesion in UA/NSTEMI and might therefore serve as non-invasive determinants of the population that is at high risk for subsequent adverse events.

Limitations of D-dimer testing in unselected inpatients with suspected venous thromboembolism

PURPOSE

To determine the utility and limitations of D-dimer testing for the evaluation of venous thromboembolism in hospitalized patients.

METHODS

We performed D-dimer testing by four different methods in unselected inpatients undergoing radiologic evaluation for possible venous thromboembolism. We included patients with a history of malignancy, recent surgery, thrombosis, and anticoagulation treatment. C-reactive protein levels were assayed as a measure of inflammation.

RESULTS

Of 45 patients with radiographically proven proximal deep venous thrombosis or pulmonary embolism, 43 had elevated D-dimer levels by enzyme-linked immunosorbent assay (ELISA) (sensitivity, 96%); the specificity of the test was 23% (36/157). The qualitative non-ELISA tests had higher specificities, but their sensitivities were <70%. Nineteen patients (42%) with thrombosis had false-negative D-dimer tests by at least one assay. The specificity of the tests decreased with increasing duration of hospitalization, increasing age, and increasing C-reactive protein levels. D-dimer testing had little or no utility in distinguishing patients with thrombosis from those without in patients who had been hospitalized for more than 3 days, were older than 60 years, or had C-reactive protein levels in the highest quartile.

CONCLUSION

In unselected inpatients, D-dimer testing has limited clinical utility because of its poor specificity. This is particularly true for older patients, those who have undergone prolonged hospitalization, and those with markedly elevated C-reactive protein levels. In some patient subsets, a negative non-ELISA D-dimer test cannot discriminate between inpatients with and without thrombosis.

Influence of two non-ionic radiographic contrast media with different osmolalities on coagulation in invasive cardiology. A prospective, randomised comparative study

PURPOSE

To investigate the influence of two non-ionic radiographic contrast media with different osmolality on thrombocytic function and the plasmatic coagulation system.

MATERIAL AND METHODS

The study was carried out as a randomised, prospective, comparative study with two contrast media in a heart catheter laboratory.

RESULTS

Activating influences on platelet aggregation, procoagulatory or profibrinolytic functions or injury to the endothelium could be ruled out. Apparently, also differences in substance properties, such as the media's ionic character or osmolality had no demonstrable influence on the interaction with haemostatis and blood vessels. An adjuvant, antithrombotic therapy was carried out, which consisted of platelet aggregation inhibitors and heparins.

CONCLUSION

Our findings agree with the results of recent clinical trials, which demonstrated no relevant disadvantage of non-ionic contrast media as regards thrombotic complications.

Evaluation of Coagulation Markers for Early Diagnosis of Acute Coronary Syndromes in the Emergency Room

Background: Diagnosis of acute coronary syndromes (ACS) is a major challenge for emergency physicians. Because soluble fibrin (sF) has been suggested as a potential early marker of impending myocardial ischemia, we were interested whether a sF bedside test could help in early identification of patients with ACS in the emergency department.

Methods: We evaluated plasma coagulation markers, including a newly developed sF bedside test, prothrombin fragment (F1+2), sF, and D-dimer, in a cross-sectional trial with 184 patients suggestive of ACS.

Results: Whereas 76% (13 of 17) of patients with unstable angina pectoris (UAP) had a positive sF bedside test, only 10 of 33 patients (30%) with non-ST-segment-elevation myocardial infarction and 10 of 44 patients (23%) with ST-elevation myocardial infarction tested positive. Three percent of controls (1 of 33) and 11% of patients (6 of 57) with preexisting stable angina had a positive sF bedside test (P &lt;0.001 for noncardiac chest pain vs ACS), yielding an overall specificity of 92% and a sensitivity of 35%. The sensitivity of the established coagulation markers was significantly less to detect ACS (11% for F1+2, 20% for thrombus precursor protein, and 18% for D-dimer; P &lt;0.02 vs sF bedside test). The sF bedside test presented the earliest objective indicator of impending myocardial damage in the majority (10 of 13) of ACS patients with a normal or nondiagnostic electrocardiogram (ECG).

Conclusions: A sF bedside test offers a specific tool for early identification of patients with ACS in an emergency department setting, although its sensitivity seems sufficient only for the early identification of patients with UAP. A sF bedside test could be useful, particularly in UAP patients with a nondiagnostic ECG.

Levels of haemostatic factors, arteriosclerosis and cardiovascular disease

Plasma levels of haemostasis factors (HFs) such as fibrinogen, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and D-dimer may be markers of arteriosclerosis for the following reasons: There seems to be no difference in levels of HFs between patients with longstanding stable angina and those with an isolated myocardial infarction. HF levels are generally positively associated with subclinical arteriosclerosis as determined by ankle-arm index and carotid ultrasonography in asymptomatic individuals. Levels of most HFs are positively associated with inflammation, which is an essential part of the initiation and progression of the disease. A rough classification is assigned to the associations found in under (2) and (3). Fibrinogen is strongly associated with subclinical arteriosclerosis and with inflammation; Factor VII is not, while an intermediate group is formed by, for instance, von Willebrand Factor (vWF), Factor VIII (F VIII), t-PA, PAI-1, and D-dimer. Also, the associations of HFs with cardiovascular events follow a similar pattern. Fibrinogen is a strong and consistent risk factor in several studies, Factor VII is not, and a similar intermediate group as mentioned under (2) and (3) exists. It suggests that the risk of cardiovascular events in relation to HF levels is explained by their identity as markers of arteriosclerosis. A causal association between HF levels and the disease is not proven. Out of the HF, the markers of coagulation such as thrombin-antithrombin complex and of fibrinolysis such as D-dimer are more likely to act causally. Increased levels indicate that they are markers of arteriosclerosis, but in addition, they may reflect a low-grade, continuous formation and subsequent lysis of fibrin in the disease. As the latter reflects an increased tendency to thrombosis, a causal association of levels of markers of coagulation and fibrinolysis with arteriosclerosis, although not yet proven, seems likely.

Plasma fibrin D-dimer levels and risk of stable coronary artery disease: results of a large case-control study

Increased levels of fibrin D-dimer are indicative of a hypercoagulable state, as found in acute coronary syndromes. Few well-controlled studies have assessed D-dimers in patients with stable coronary artery disease (CAD). We measured levels of D-dimers (in ng/mL by enzyme-linked immunosorbent assay) in 312 patients with angiographically proved CAD and stable angina pectoris and in 477 age- and sex-matched healthy blood donors. Demographic characteristics were assessed by a standardized questionnaire, and a complete lipid profile was performed for all subjects. In addition, a variety of other markers of hemostasis and inflammation were measured. The distribution of D-dimer levels was skewed to the right, and plasma median levels were higher in cases than in controls (median: 11.2 vs 2.8 ng/mL; P<0.001). In controls, correlations of D-dimer were found with fibrinogen, plasma viscosity, and interleukin-6. In logistic regression analysis, the age- and sex-adjusted odds ratio (OR) for the presence of CAD was 2.6 (95% confidence interval [CI], 1.9 to 3.5) when the highest quartile of the D-dimer distribution was compared with the combined lower 3 quartiles. The OR did not change appreciably after controlling for nonlipid risk factors (OR, 2.7; 95% CI, 1.9 to 3.9) and remained significant after further adjustment for other hemostatic parameters (OR, 2.4; 95% CI, 1.7 to 3.3) and markers of inflammation (OR, 2.1; 95% CI, 1.5 to 2.9). Plasma D-dimer levels are strongly and independently associated with the presence of CAD in patients with stable angina pectoris. These results support the concept of a contribution of intravascular fibrin to atherothrombogenesis.

Fibrin D-dimer and coronary heart disease: prospective study and meta-analysis

BACKGROUND

It is unknown whether modest increases of fibrin D-dimer, a circulating marker of fibrin turnover, are relevant to coronary heart disease (CHD) in the general population.

METHODS AND RESULTS

We measured serum concentrations of D-dimer antigen in the stored baseline blood samples of 630 CHD cases and 1269 controls "nested" in a prospective cohort of 5661 men who were monitored for 16 years, and we conducted a meta-analysis of previous relevant studies to place our findings in context. In a comparison of men in the top third compared with those in the bottom third of baseline fibrin D-dimer values (tertile cutoffs, >94 versus <49 ng/mL), the odds ratio for CHD was 1.67 (95% CI, 1.31 to 2.13; P<0.0001) after adjustments for age and town. The odds ratio increased slightly after further adjustment for smoking, other classic risk factors, and indicators of socioeconomic status (1.79; 95% CI, 1.36 to 2.36). Strong correlations were observed of fibrin D-dimer values with circulating concentrations of C-reactive protein and serum amyloid A protein but not with smoking, blood lipids, blood pressure, and other risk factors.

CONCLUSION

Although there may be an association between circulating D-dimer values and CHD, further studies are needed to determine the extent to which this is causal.