Fibrin and fibrinogen-related antigens in patients with stable and unstable coronary artery disease

Sex-specific associations between systolic, diastolic and pulse pressure and hemostatic parameters in the population-based KORA-Fit study: a cross-sectional study

BACKGROUND

Several prior studies postulated an effect of hypertension on coagulation factors. However, population-based studies investigating the sex-specific associations between hypertension and hemostatic parameters are scarce. Therefore, we investigated the relationship between blood pressure and parameters of coagulation, namely activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen, factor VIII, antithrombin III, protein C, protein S, and D-dimer in men and women from the general population.

METHODS

Based on 803 participants (376 men, 427 women) from the KORA-Fit Study the sex-specific relationship between systolic, diastolic, and pulse pressure and commonly measured coagulation factors were investigated using multivariable-adjusted linear regression models.

RESULTS

Hypertensive males had significantly higher median fibrinogen levels and factor VIII activity in comparison to normotensive males. There was a statistically significant difference between females with and without hypertension regarding the parameter fibrinogen, D-dimers, Protein S activity, and factor VIII activity. In multivariable linear regression analyses no significant association between systolic blood pressure, diastolic blood pressure, as well as pulse pressure and the investigated hemostatic parameters was found in men. In women, a significant positive association could be observed between systolic blood pressure and D-dimer level [β-estimate per mmHg increase 3.37 (95% CI 0.935-5.804; p = 0.007)] and between pulse pressure and D-dimer level [β-estimate per mmHg increase 5.351 (95% CI 1.772-8.930; p = 0.003)].

CONCLUSIONS

It appears that sex differences exist in the association between blood pressure parameters and commonly measured coagulation markers in the general population. Further studies are needed to identify the underlying causes.

D-dimer for screening of aortic dissection in patients with ST-elevation myocardial infarction

BACKGROUND

Acute aortic dissection (AAD) with concurrent ST-segment elevation myocardial infarction (STEMI) is relatively rare and sometimes overlooked. As D-dimer testing has been reported to have high sensitivity to diagnose AAD in a clinical scale, Aortic Dissection Detection Risk Score (ADD-RS), a point-of-care D-dimer analyzer capable of measuring in 10 min would be useful to deny AAD with concurrent STEMI. However, an optimal cut-off value of D-dimer in such population remains unclear. Therefore, the aim of this study was to elucidate the optimal D-dimer threshold in patients clinically diagnosed with STEMI.

METHODS

This retrospective cohort study was conducted at two tertiary care centers between 2014 and 2019. Patients clinically diagnosed with STEMI who underwent serum D-dimer measurement on hospital arrival were included. The primary outcome was the diagnosis of AAD. The area under the receiver operating characteristic curve (AUROC) for D-dimer values to diagnose AAD was evaluated, particularly in patients with low to moderate risks of AAD (1 of ADD-RS). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated with several cut-off values.

RESULTS

A total of 322 patients were included, and 28 were diagnosed with AAD. The AUROC for D-dimer to diagnose AAD was 0.970 (95% confidence interval: 0.948-0.993) in 262 patients with 1 of ADD-RS. If D-dimer ≥750 ng/mL was used as a cut-off value, sensitivity, specificity, PPV and NPV were 100%, 86.4%, 37.7%, and 100%, respectively. AAD could be denied in 209 (79.8%) patients using the cut-off value (D-dimer <750 ng/mL).

CONCLUSIONS

Serum D-dimer ≥750 ng/mL exhibited high sensitivity and NPV to diagnose AAD with concurrent STEMI, while the ADD-RS originally utilized ≥500 ng/mL as a cut-off for any suspected AAD. A point-of-care D-dimer measurement with the new cut-off would be useful to rule-out AAD among patients with STEMI.

Diagnostic performance and predictive value of D-dimer testing in patients referred to the emergency department for suspected myocardial infarction

PURPOSE

The study sought to assess the performance of D-dimer testing for the diagnosis of acute coronary syndrome (ACS) and prediction of outcomes in patients admitted for suspected myocardial infarction (MI).

RESULTS

A total of 3,557 patients with suspected ACS presenting to a single center with a broad range of symptoms including atypical chest pain were retrospectively recruited between 02/2012-01/2019. Of the study cohort, 435 patients had unstable angina (UA), 420 non-ST-segment elevation myocardial infarction (NSTEMI), 22 ST-segment elevation myocardial infarction (STEMI), and 2,680 non-coronary chest pain. Plasma D-dimer concentrations in patients with hs-cTnT >14 ng/L differed significantly from those with hs-cTnT <14 ng/L (1.5 ± 3.6 mg/L vs. 0.5 ± 0.8 mg/L; p<0.0001). Positive predictive value for a final diagnosis of ACS increased proportionally to rising D-dimer concentrations. The area under the curve (AUC) to discriminate STEMI from non-coronary chest pain (AUC 0.729, 95% confidence interval [CI] 0.71-0.75) was moderate and differed not significantly to UA (AUC 0.595, 95% CI 0.58-0.61; p=0.0653). During a median follow-up of 29 months, higher D-dimer was associated with a significantly increased risk of recurrent MI (quartile 4 vs. 1: hazard ratio [HR], 6.9 [95% CI 1.2-39.9]; p<0.0001) and higher all-cause mortality (HR, 17.4 [95% CI 4.3-69.9]; p<0.0001). D-dimer was an independent predictor of all-cause mortality (p<0.0001) and subsequent MI events (p=0.0333).

CONCLUSIONS

D-dimer testing revealed great potential to provide independent prognostic information on recurrent MI and all-cause mortality. However, D-dimers do not improve the diagnostic performance except if values exceed the 95^th percentile.

Elevated plasma D-dimer levels are associated with risk of future incident venous thromboembolism

BACKGROUND

D-dimer, a global biomarker for activation of the coagulation and fibrinolysis systems, is useful in assessing individual risk of venous thromboembolism (VTE) recurrence. However, there is limited information on the association between D-dimer and risk of a first lifetime VTE event.

OBJECTIVES

To investigate the association between plasma D-dimer levels and risk of future incident VTE.

METHODS

A population-based nested case-control study, comprising 414 VTE patients and 843 randomly selected age- and sex-matched controls, was derived from the Tromsø Study (1994-2007). D-dimer was measured in plasma samples collected at cohort baseline (1994-95). Odds ratios (ORs) for VTE with 95% confidence intervals (CIs) were estimated according to quartile cut-offs of D-dimer levels determined in controls.

RESULTS

The risk of VTE increased across quartiles of D-dimer levels (P_trend = 0.014) in the age- and sex-adjusted model. Participants with plasma D-dimer levels in the highest quartile (≥152 ng/mL) had an OR for VTE of 1.65 (95% CI 1.14-2.40) compared with those in the lowest quartile (<94 ng/mL). The ORs were marginally attenuated after additional adjustment for body mass index (BMI) (OR 1.51, 95% CI 1.04-2.20) and C-reactive protein (CRP) (OR 1.34, 95% CI 0.90-1.98). Similar results were obtained for VTE subgroups, i.e. deep vein thrombosis, pulmonary embolism, and provoked/unprovoked events.

CONCLUSION

Our results indicate that elevated plasma D-dimer levels are associated with increased risk of incident VTE. However, the attenuation of risk estimates upon additional adjustment for BMI and CRP suggests that D-dimer partly reflects underlying conditions associated with obesity and an inflammatory state.

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.

Predictors for layered coronary plaques: an optical coherence tomography study

Healed coronary plaques, morphologically characterized by a layered pattern, are signatures of previous plaque disruption and healing. Recent optical coherence tomography (OCT) studies showed that layered plaque is associated with vascular vulnerability. However, factors associated with layered plaques have not been studied. The aim of this study was to investigate predictors for layered plaque at the culprit plaques and at non-culprit plaques. Patients with coronary artery disease who underwent pre-intervention OCT imaging of the culprit lesion were included. Layered plaques were defined as plaques with one or more layers of different optical density and a clear demarcation from underlying components. Among 313 patients, layered plaque at the culprit lesion was observed in 18.8% of ST-segment elevation myocardial infarction patients, 36.3% of non-ST-segment elevation acute coronary syndrome patients, and 53.4% of stable angina pectoris (SAP) patients (p < 0.001). In the multivariable model, SAP, multivessel disease, type B2/C lesion, and diameter stenosis > 70% were independent predictors for layered plaque at the culprit lesion. In addition, 394 non-culprit plaques in 190 patients were assessed to explore predictors for layered plaques at non-culprit lesions. SAP, and thin-cap fibroatheroma and layered plaque at the culprit lesion were independent predictors for layered plaques at non-culprit lesions. In conclusion, clinical presentation of SAP was a strong predictor for layered plaque at both culprit plaques and non-culprit plaques. Development and biologic significance of layered plaques may be related to a balance between pan-vascular vulnerability and endogenous anti-thrombotic protective mechanism.

D-dimer and the incidence of heart failure and mortality after acute myocardial infarction

OBJECTIVE

D-dimer might serve as a marker of thrombogenesis and a hypercoagulable state following plaque rupture. Few studies explore the association between baseline D-dimer levels and the incidence of heart failure (HF), all-cause mortality in an acute myocardial infarction (AMI) population. We aimed to explore this association.

METHODS

We enrolled 4504 consecutive patients with AMI with complete data in a prospective cohort study and explored the association of plasma D-dimer levels on admission and the incidence of HF, all-cause mortality.

RESULTS

Over a median follow-up of 1 year, 1112 (24.7%) patients developed in-hospital HF, 542 (16.7%) patients developed HF after hospitalisation and 233 (7.1%) patients died. After full adjustments for other relevant clinical covariates, patients with D-dimer values in quartile 3 (Q3) had 1.51 times (95% CI 1.12 to 2.04) and in Q4 had 1.49 times (95% CI 1.09 to 2.04) as high as the risk of HF after hospitalisation compared with patients in Q1. Patients with D-dimer values in Q4 had more than a twofold (HR 2.34; 95% CI 1.33 to 4.13) increased risk of death compared with patients in Q1 (p<0.001). But there was no association between D-dimer levels and in-hospital HF in the adjusted models.

CONCLUSIONS

D-dimer was found to be associated with the incidence of HF after hospitalisation and all-cause mortality in patients with AMI.

Predictive values of D-dimer for the long-term prognosis of acute ST-segment elevation infarction: A retrospective study in southwestern China

D-dimer is a primary degradation product of cross-linked fibrin, and can be an effective diagnostic factor of venous thromboembolism. However, its prognostic role in patients with acute ST-segment elevation myocardial infarction (STEMI) remains controversial. This study aimed to investigate whether D-dimer has a predictive value for long-term prognosis in patients with STEMI.We retrospectively enrolled 872 STEMI patients treated with primary percutaneous coronary intervention. Patients were divided into quartiles according to their admission D-dimer increased multiple, with the highest quartile (G4) (n = 219) defined as increased multiple ≧1.33, and the lowest quartile (G1) (n = 215) as increased multiple ≦0.33.Compared with G1, higher in-hospital heart failure (40.2% vs 10.2%, P < .0001), malignant arrhythmia (14.2% vs 2.3%, P < .0001), and all-cause mortality (5.9% vs 0%, P < .0001) rates were observed in G4. After a follow-up period of 29 months, 84 patients had died. In the Cox multivariate analysis, a high admission D-dimer increased multiple (≧1.33) was found to be an independent predictor of all-cause mortality (hazards ratio: 2.53, 95% confidence interval: 1.02-6.26, P = .045).Thus, there was an association between a high D-dimer level and the increase in in-hospital major adverse cardiovascular events, such as heart failure, malignant arrhythmias, and death. High D-dimer level was also an independent predictor of long-term all-cause mortality.

Diagnostic Value of D-Dimer in Acute Myocardial Infarction Among Patients With Suspected Acute Coronary Syndrome

Background

The role of D-dimer as a diagnostic marker in myocardial infarction (MI) and acute coronary syndrome (ACS) is still a question. The aim of this study was to evaluate the diagnostic value of D-dimer in the diagnosis of AMI in patients suspected with ACS.

Methods

This cross-sectional study was conducted on patients suspected with ACS. Serial standard 12-lead electrocardiogram (ECG), D-dimer, and troponin tests were done for all the patients. According to the examinations, ECG changes, and troponin, patients were allocated into two groups of MI and unstable angina (UA). Chi-square, independent t-test, and Pearson correlation test were used by SPSS ver, 17. Cut-off point of D-dimer for MI diagnosis was evaluated by receiver operating characteristic (ROC) curve analysis.

Results

Seventy-five patients with a mean age of 63.1 ± 9.75 years were studied in two groups of MI (n = 34) and UA (n = 41). Patients were homogeneous based on age, gender, and risk factors for diabetes and dyslipidemia. D-dimer in patients with MI patients was higher than in patients with UA (P = 0.001). The optimal cut-off point of D-dimer for diagnosis of MI was 548 mEq/L with sensitivity and specifity of 63.4% and 91.2%, respectively.

Conclusions

Based on the results of this study, it seems that the measurement of D-dimer serum level can be appropriate as a marker with high sensitivity and relatively high specificity for differentiating MI from UA in patients with suspected ACS.

Admission D-dimer testing for differentiating acute aortic dissection from other causes of acute chest pain

INTRODUCTION

The present study aims to evaluate the utility of D-dimer testing for differentiating the causes of acute chest pain, including acute aortic dissection (AAD), pulmonary embolism (PE), acute myocardial infarction (AMI), unstable angina (UA), and other uncertain diagnoses of chest pain.

MATERIAL AND METHODS

Consecutive patients admitted for acute chest pain within 24 h from symptom onset were enrolled prospectively, and plasma D-dimer levels were measured on admission. Diagnoses of AAD, PE, AMI, and UA were confirmed by standard methods.

RESULTS

A total of 790 patients were enrolled, including 202 AAD, 43 PE, 315 AMI, 136 UA, and 94 cases of other uncertain diagnoses. D-dimer levels were significantly higher in patients with AAD and PE than in those with AMI, UA, and other uncertain diagnoses (p < 0.001), but they were comparable between patients with AAD and PE (p = 0.065). Moreover, patients with type A AAD had higher D-dimer levels than those with type B AAD (p = 0.022). Receiver operating characteristic (ROC) curve analysis showed that a D-dimer level < 0.5 µg/ml was a good predictor for ruling out AAD, with a sensitivity of 94.0% and a specificity of 56.8%. At a cut-off level of 0.5 µg/ml, the negative and positive likelihood ratios were 0.10 and 2.18, respectively, with a positive predictive value of 42.6% and a negative predictive value of 96.6%.

CONCLUSIONS

The D-dimer level within 24 h after symptom onset might be helpful for differentiating AAD from other causes of chest pain.

Fibrinogen in relation to degree and composition of coronary plaque on intravascular ultrasound in patients undergoing coronary angiography

OBJECTIVE

The aim of this study was to provide additional insight into the role of fibrinogen in coronary artery disease by investigating the associations between plasma fibrinogen with both degree and composition of coronary atherosclerosis as determined by virtual histology-intravascular ultrasound.

PATIENTS AND METHODS

In 581 patients undergoing coronary angiography for acute coronary syndrome (ACS) or stable angina pectoris, preprocedural blood samples were drawn for fibrinogen, C-reactive protein (CRP), interleukin-6, and plasminogen activator inhibitor-1 measurements, and virtual histology-intravascular ultrasound of a nonculprit coronary artery was performed. The degree [plaque volume, plaque burden (PB), and lesions with PB≥70%] and the composition of coronary atherosclerotic plaque (fibrous, fibrofatty, dense calcium, necrotic core tissue, and thin-cap fibroatheroma lesions) were assessed.

RESULTS

Fibrinogen showed a tendency toward a positive association with PB [β (95% CI): 2.55 (-0.52-5.61) increase in PB per ln(g/l) fibrinogen, P=0.09], which was driven significantly by an association in the ACS subgroup [β (95% CI): 4.11 (0.01-8.21) increase in PB per ln(g/l) fibrinogen, P=0.049]. Fibrinogen was also related to the presence of lesions with PB 70% or more in both the full cohort [OR (95% CI): 2.27 (1.17-4.43), P=0.016] and ACS patients [OR (95% CI): 2.92 (1.17-7.29), P=0.022]. All associations were independent of established cardiovascular risk factors, but not CRP. Interleukin-6 and plasminogen activator inhibitor-1 did not provide incremental value to fibrinogen when examining the associations with degree of atherosclerosis. Substantial associations with plaque composition were absent.

CONCLUSION

Fibrinogen is associated with degree of coronary atherosclerosis, especially in ACS patients. However, whether this association is independent of CRP might be questioned and needs further investigation.

Long-term prognostic utility of pentraxin 3 and D-dimer as compared to high-sensitivity C-reactive protein and B-type natriuretic peptide in suspected acute coronary syndrome

BACKGROUND

Vascular inflammation plays a key role in the development of atherosclerosis and acute coronary syndrome (ACS), and pentraxin 3 (PTX3) is one of several novel, promising markers of inflammation. In addition, D-dimer might serve as a marker of thrombogenesis and a hypercoagulable state following plaque rupture. The present study assesses the prognostic utility of these two biomarkers as compared to high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP), in addition to conventional clinical risk factors for coronary heart disease in patients with suspected ACS.

METHODS

Chest pain patients with suspected ACS (n = 871) were consecutively included in a prospective, observational study with a follow-up time of 84 months.

RESULTS

At 7-year follow-up, 332 patients had died and 203 had suffered an adverse troponin T-positive, non-fatal cardiac event. In the multivariate analysis, levels of PTX3 above 5.88 ng/mL (median) and D-dimer above 436 µg/L (lower limit upper quartile) independently predicted mortality (HR 1.60 [95% CI 1.10-2.33]; p = 0.014 and HR 1.83 [95% CI 1.20-2.78]; p = 0.005, respectively). Also, BNP levels above 310.75 pg/mL (lower limit upper quartile) (HR 2.16 [95% CI 1.37-3.42]; p = 0.001), but not hsCRP, independently predicted mortality. Only hsCRP and BNP also predicted future myocardial infarction (HR 1.59 [95% CI 1.05-2.40]; p = 0.029 and HR 1.91 [95% CI 1.10-3.31]; p = 0.021, respectively).

CONCLUSION

High levels of PTX3, D-dimer and BNP were found to be independent, long-term predictors of all-cause mortality in chest pain patients with a suspected ACS. hsCRP and BNP also predicted future myocardial infarction.

Markers of thrombin generation are associated with myocardial necrosis and left ventricular impairment in patients with ST-elevation myocardial infarction

Introduction

Platelet activation, thrombin generation and fibrin formation play important roles in intracoronary thrombus formation, which may lead to acute myocardial infarction.

We investigated whether the prothrombotic markers D-dimer, pro-thrombin fragment 1 + 2 (F1 + 2) and endogenous thrombin potential (ETP) are associated with myocardial necrosis assessed by Troponin T (TnT), and left ventricular impairment assessed by left ventricular ejection fraction (LVEF) and N-terminal pro b-type natriuretic peptide (NT-proBNP).

Materials/Methods

Patients (n = 987) with ST-elevation mycardial infarction (STEMI) were included. Blood samples were drawn at a median time of 24 h after onset of symptoms.

Results

Statistically significant correlations were found between both peak TnT and D-dimer (p < 0.001) and F1 + 2 (p < 0.001), and between NT-proBNP and D-dimer (p = 0.001) and F1 + 2 (p < 0.001). When dividing TnT and NT-proBNP levels into quartiles there were significant trends for increased levels of both markers across quartiles (all p < 0.001) D-dimer remained significantly associated with NT-proBNP after adjustments for covariates (p = 0.001) whereas the association between NTproBNP and F1 + 2 was no longer statistically significant (p = 0.324).

A significant inverse correlation was found between LVEF and D-dimer (p < 0.001) and F1 + 2 (p = 0.013). When dichotomizing LVEF levels at 40 %, we observed significantly higher levels of both D-dimer (p < 0.001) and F1 + 2 (p = 0.016) in the group with low EF (n = 147).

Summary/conclusion

In our cohort of STEMI patients we demonstrated that levels of D-dimer and F1 + 2 were significantly associated with myocardial necrosis as assessed by peak TnT. High levels of these coagulation markers in patients with low LVEF and high NTproBNP may indicate a hypercoagulable state in patients with impaired myocardial function.

Predictive value of elevated D-dimer in patients undergoing primary angioplasty for ST elevation myocardial infarction

The aim of this study was to evaluate the prognostic value of D-dimer in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). The prognostic value of D-dimer has been documented in patients with acute coronary syndrome without ST-segment elevation. However, its value in acute ST-segment elevation myocardial infarction (STEMI) remains unclear. We prospectively enrolled 453 consecutive STEMI patients (mean age 55.6 ± 12.4 years, 364 male, 89 female) undergoing primary PCI. The study population was divided into tertiles based on admission D-dimer values. The high D-dimer group (n = 151) was defined as a value in the third tertile [>0.72 ug/ml fibrinogen equivalent units (FEU)], and the low D-dimer group (n = 302) included those patients with a value in the lower two tertiles (≤0.72 ug/ml FEU). Clinical characteristics, in-hospital and 6-month outcomes of primary PCI were analyzed. The patients of the high D-dimer group were older (mean age 60.1 ± 13.5 versus 52.4 ± 10.6, P < 0.001). Higher in-hospital cardiovascular mortality and 6-month all-cause mortality rates were observed in the high D-dimer group (7.2 versus 0.6%, P < 0.001 and 13.9 versus 2%, P < 0.001, respectively). In Cox multivariate analysis; a high admission D-dimer value (>0.72 ug/ml FEU) was found to be a powerful independent predictor of 6-month all-cause mortality (odds ratio: 10.1, 95% confidence interval: 1.24-42.73, P = 0.03). These results suggest that a high admission D-dimer, level was associated with increased in-hospital cardiovascular mortality and 6-month all-cause mortality in patients with STEMI undergoing primary PCI.

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.

Dietary oil modifies the plasma proteome during aging in the rat

Fatty acids and other components of the diet may modulate, among others, mechanisms involved in homeostasis, aging, and age-related diseases. Using a proteomic approach, we have studied how dietary oil affected plasma proteins in young (6 months) or old (24 months) rats fed lifelong with two experimental diets enriched in either sunflower or virgin olive oil. After the depletion of the most abundant proteins, levels of less abundant proteins were studied using two-dimensional electrophoresis and mass spectrometry. Our results showed that compared with the sunflower oil diet, the virgin olive oil diet induced significant decreases of plasma levels of acute phase proteins such as inter-alpha inhibitor H4P heavy chain (at 6 months), hemopexin precursor (at 6 and 24 months), preprohaptoglobin precursor (at 6 and 24 months), and α-2-HS glycoprotein (at 6 and 24 months); antioxidant proteins such as type II peroxiredoxin (at 24 months); proteins related with coagulation such as fibrinogen γ-chain precursor (at 24 months), T-kininogen 1 precursor (at 6 and 24 months), and apolipoprotein H (at 6 and 24 months); or with lipid metabolism and transport such as apolipoprotein E (at 6 and 24 months) and apolipoprotein A-IV (at 24 months). The same diet increased the levels of apolipoprotein A-1 (at 6 and 24 months), diminishing in general the changes that occurred with age. Our unbiased analysis reinforces the beneficial role of a diet rich in virgin olive oil compared with a diet rich in sunflower oil, modulating inflammation, homeostasis, oxidative stress, and cardiovascular risk during aging.

The role of serum D-dimer level in the diagnosis of patients admitted to the emergency department complaining of chest pain

This study investigated D-dimer levels in 241 patients admitted to the emergency department with sudden-onset chest pain. The patient group included those diagnosed with acute coronary syndrome (ACS; i.e., unstable angina pectoris [USAP], non-ST elevated myocardial infarction [NSTEMI], ST-elevated myocardial infarction [STEMI]); the control group included those diagnosed with non-cardiac chest pain. Mean serum levels of D-dimer, creatine kinase-MB (CK-MB) and troponin I (TPI) were compared between the groups. Levels of D-dimer, CK-MB and TPI in the patient group were significantly higher than in the control group. There were also significantly higher D-dimer, CK-MB and TPI levels in the STEMI and NSTEMI patient subgroups compared with the control group. Only the D-dimer level was significantly higher in the USAP subgroup versus the control group. The sensitivity and specificity of D-dimer for ACS were 83.7% and 95.4%, respectively, suggesting that evaluating D-dimer levels might be useful in the emergency room for diagnosing ACS and predicting mortality in patients presenting with acute chest pain.

D-dimer as a marker for early diagnosis of acute mesenteric ischemia

INTRODUCTION

Acute obstruction of mesenteric artery generally has an unfavorable prognosis because of late diagnosis. In this study we evaluated the diagnostic value of plasma D-dimer level as an early indicator in acute mesenteric ischemia in rats caused by ligation of superior mesenteric artery.

MATERIALS AND METHODS

Twenty-eight mature male Wistar rats were used in the study. These were divided into four groups, each consisting of seven rats. In group I, after performing a simple laparotomy, blood was sampled at minute 30. In group II, first the superior mesenteric artery was ligated, and blood samples were taken at the 30th minute. Group III consisted of rats undergoing a simple laparotomy and blood samples were taken 7 h later. From the subjects in group IV blood samples were obtained 7 h after the ligation of their superior mesenteric artery.

RESULTS

Plasma D-dimer levels of the ligated groups were significantly higher both at the 30th minute and the 7th hour compared to the levels of those having undergone simple laparotomies (p<0.002). Likewise, this level was higher in the 7th hour blood samples of the ligated group than in the 30th minute (p<0.008).

CONCLUSIONS

In rats undergoing acute mesenteric ischemia by ligation of superior mesenteric artery, plasma D-dimer levels increase with the duration of the intestinal ischemia period. This finding suggests that the measurement of the plasma D-dimer levels might be a useful tool for the early diagnosis of acute mesenteric obstruction.

Inflammation and plaque vulnerability

Development of a thrombus at the site of an atherosclerotic plaque initiates abrupt arterial occlusion and is the proximate event responsible for the vast majority of acute ischemic syndromes. In nearly 75% of cases thrombus overlies a disrupted or ruptured plaque whereas the remainder of the thrombi overly an intact plaque with superficial endothelial erosion. Over the past several years, it has been recognized that plaque composition rather than plaque size or stenosis severity is important for plaque rupture and subsequent thrombosis. Ruptured plaques, and by inference, plaques prone to rupture, tend to be large in size with associated expansive arterial remodeling, thin fibrous cap with a thick or large necrotic lipid core with immuno-inflammatory cell infiltration in fibrous cap and adventitia and increased plaque neovascularity and intraplaque hemorrhage. The size of the necrotic lipid core and extent and location of plaque inflammation appear to be key factors in determining plaque instability. Inflammation and immune cell activation appears to play a key role in the loss of collagen in the fibrous cap, a prelude to fibrous cap rupture, through release of collagen degrading enzymes. Furthermore, inflammation may also play a key role in the death of collagen synthesizing smooth muscle cells which further contributes to loss of fibrous cap integrity. Inflammation also is likely a key player in the ensuing thrombosis that follows plaque disruption through the elaboration of the pro-coagulant protein, tissue factor. An improved understanding of the pathophysiology of plaque vulnerability and subsequent athero-thrombosis should provide novel insights into improved prevention of athero-thrombotic cardiovascular events.

D-Dimer for venous thromboembolism diagnosis: 20 years later

Twenty years after its first use in the diagnostic workup of suspected venous thromboembolism (VTE), fibrin D-dimer (DD) testing has gained wide acceptance for ruling out this disease. The test is particularly useful in the outpatient population referred to the emergency department because of suspected deep vein thrombosis (DVT) or pulmonary embolism (PE), in which the ruling out capacity concerns every third patient clinically suspected of having the disease. This usefulness is based on the high sensitivity of the test to the presence of VTE, at least for some assays. Due to its poor specificity precluding its use for ruling in VTE, DD testing must be integrated in comprehensive, sequential diagnostic strategies that include clinical probability assessment and imaging techniques such as lower limb venous compression ultrasonography for suspected DVT or multi-slice helical computed tomography for suspected PE. The present narrative review updates the data available on the use of the various commercially available DD assays in the diagnostic approach of clinically suspected VTE in distinct patient populations or situations, including outpatients and inpatients, patients with cancer, older age, pregnancy, a suspected recurrent event, limited thrombus burden, and patients already on anticoagulant treatment.

Xa inhibition and coagulation activity--the influence of prolonged dalteparin treatment and gender in patients with acute coronary syndrome and healthy individuals

BACKGROUND

We evaluated coagulation activity in relation to gender in patients with acute coronary syndromes and in healthy individuals of similar age, and related coagulation activity to levels of Xa inhibition during dalteparin treatment.

METHODS

Serial blood samples were obtained from 555 (172 women) of 2267 patients in the Scandinavian FRISC II study, and a single sample in 457 (151 women) apparently healthy age- and sex-matched individuals. After randomization, all patients received dalteparin 120 IU/kg s.c. (maximum 10,000 IU) twice daily for 5 to 7 days inhospital and thereafter placebo (n = 285) or sex- and weight-adjusted doses of dalteparin (5000 or 7500 IU) twice daily (n = 270) for 3 months.

RESULTS

Before randomization, 96% of the patients had open-label anticoagulation with unfractionated heparin or dalteparin. Therapeutic anti-Xa levels (> 0.5 IU/mL) were found in 74%, 55%, 58%, and 33% of the dalteparin-treated patients at randomization, 2 days, 4 to 7 weeks, and 3 months, respectively, and were significantly related to lower levels of coagulation activity, ie, factor VIIa, prothrombin fragment 1+2, and D-dimer, during prolonged treatment. Female patients had higher anti-Xa levels than men at randomization (median 0.69 vs 0.60 IU/mL, P = .01) and at 2 days (0.65 vs 0.59 IU/mL, P < .001). Female patients had also significantly higher levels of all 3 coagulation markers at randomization, 2 days, 4 to 7 weeks, and 3 and 6 months. Similarly, healthy women had higher prothrombin fragment 1+2 levels (median 1.19 vs 0.94 nmol/L) and D-dimer levels than men (26 vs 21 microg/L) (both P < .001).

CONCLUSIONS

Despite weight-adjusted dosing, female patients reached higher anti-Xa levels, suggesting increased sensitivity to dalteparin treatment. Healthy women and female patients also had higher coagulation activity, which might increase the risk of thrombus formation. The large proportion of patients with subtherapeutic anti-Xa during prolonged dalteparin treatment may reflect poor compliance and could thus contribute to the gradual loss of clinical efficacy.

Molecular mechanisms of plaque instability

PURPOSE OF REVIEW

Coronary artery thrombosis superimposed on a disrupted atherosclerotic plaque initiates abrupt arterial occlusion and is the proximate event responsible for 60-80% cases of acute coronary syndromes. This article provides a concise update on the evolving concepts in the pathophysiology of plaque rupture and thrombosis.

RECENT FINDINGS

Over the past several years, the critical role of plaque composition rather than plaque size or stenosis severity, in plaque rupture and thrombosis have been recognized. The necrotic lipid core and plaque inflammation appear to be key factors. Extracellular matrix loss in the fibrous cap, a prelude to rupture, is attributed to matrix degrading enzymes as well as to death of matrix synthesizing smooth muscle cells; inflammation appears to play a critical role in both these processes. Inflammatory cell derived tissue factor is a key contributor to plaque thrombogenicity. Inflammation has also been implicated in plaque neovascularity, intraplaque hemorrhage and plaque expansion. Recent observations have also highlighted the important modulatory role of immune system in atherosclerosis and plaque composition.

SUMMARY

Improved understanding of mechanisms causing plaque instability should provide novel insights into prevention of athero-thrombotic cardiovascular events.

The effect of primary percutaneous coronary intervention as compared to tenecteplase on myeloperoxidase, pregnancy-associated plasma protein A, soluble fibrin and D-dimer in acute myocardial infarction

INTRODUCTION

Acute coronary reperfusion is accomplished pharmacologically with intravenous thrombolytic therapy or mechanically with primary percutaneous coronary intervention (PCI).

METHODS

We have determined the immediate effects of the main coronary reperfusion procedures on the plasma concentrations of myeloperoxidase (MPO), pregnancy-associated plasma protein A (PAPP-A), fibrin monomer (FM) and D-dimer (DD). We studied a total of 38 patients admitted for ST-segment elevation infarct (STEMI). 18 patients were given thrombolytic therapy with tenecteplase and 20 were treated with primary PCI.

RESULTS

The plasma concentrations of PAPP-A increased by a factor of six to eight times (p<0.001) following both reperfusion therapies. No significant increase was observed for MPO by either procedure. DD and FM concentrations both increased significantly following thrombolytic therapy, p=0.000, whereas only minor increases, although statistically significant for FM (p=0.013), were noted after PCI. DD and FM were highly correlated prior to the two treatment regimens (R=0.91), and were still highly correlated after PCI (R=0.94) and thrombolytic therapy (R=0.86). No correlation was demonstrated between PAPP-A and markers of activated coagulation.

CONCLUSIONS

This is the first report of a significant rise in the plasma concentration of PAPP-A after PCI as compared to thrombolytic treatment (p=0.002) and may indicate a greater impact of PCI than that of thrombolytic therapy on target coronary plaques.

The role of enzyme-linked immunosorbent assay D-dimer in patients with acute coronary syndrome presenting with normal cardiac enzymes

Plasma D-dimer levels, the primary degradation product of cross-linked fibrin, are elevated in acute coronary syndrome (ACS). However, the role of D-dimer in patients presenting to the Emergency Department with ACS and normal cardiac enzymes is unknown. We conducted a prospective, observational study in the Emergency Department of a major tertiary university-affiliated center. The study included 124 patients presented to the Emergency Department with ACS and normal cardiac enzymes. Blood samples were collected and assayed for D-dimer levels with the enzyme-linked immunosorbent assay (ELISA) test. The D-dimer values were correlated with the clinical, laboratory and electrocardiographic findings on admission, as well as with the catheterization findings and with hospital length of stay. ELISA D-dimer levels positively correlated with sex, hypertension and smoking (r = -0.27, P = 0.002; r = 0.33, P = 0.0002; and r = -0.24, P = 0.007, respectively). Significant correlation was also observed between ELISA D-dimer and cardiac medications including beta-blocker (r = 0.22, P = 0.01), aspirin (r = 0.18, P = 0.04), nitrate (r = 0.20, P = 0.002), acute phase reactants fibrinogen (r = 0.45, P = 0.0001) and C-reactive protein (r = 0.29, P = 0.004), ischemic electrocardiographic changes (r = 0.21, P = 0.02) and length of stay (r = 0.29, P = 0.001). The catheterization findings were also correlated with the ELISA D-dimer levels (r = 0.31, P = 0.02). The ELISA D-dimer test may add important clinical data concerning patients with ACS and normal cardiac enzymes.

Plasma markers of activated hemostasis in the early diagnosis of acute coronary syndromes

BACKGROUND

Because acute coronary syndromes (ACS) are caused by intracoronary thrombosis, plasma markers of coagulation have relevance for early diagnosis.

AIMS AND OBJECTIVES

To provide a critical review of these studies and specific attempts to close the diagnostic time gap left by traditional plasma markers of heart injury.

METHODS

Studies of ACS patients, with at least one control group, were included when blood samples were taken within 24 h after first symptoms prior to medication or intervention. Special attention was paid to studies reporting diagnostic performance, or combination of several markers into a single diagnostic index.

RESULTS

Markers with short plasma half-life (FPA, TAT, etc.) reflect ongoing thrombosis and may identify patients at increased risk. Markers with longer half-life (F1+2, D-Dimer, etc.) may be more useful to indicate a single acute thrombotic event. However, results are highly variable and depend on sampling time, clot property, degree of coronary obstruction and physiological condition. Early diagnostic performance of hemostatic markers was poor even when combined with heart injury markers.

CONCLUSIONS

Early measurement of hemostatic plasma markers in ACS patients provides pathophysiological information and may be helpful in risk stratification or to monitor anticoagulant therapy, but does not seem useful in routine clinical diagnosis of ACS.

Influence of prolonged dalteparin treatment on coagulation, fibrinolysis and inflammation in unstable coronary artery disease

BACKGROUND

Unstable coronary artery disease (CAD) is a multi-factorial disease involving thrombotic and inflammatory processes. Short-term low molecular weight (LMW) heparin treatment reduces coagulation activity and clinical events. We investigated the influence of prolonged treatment on coagulation, fibrinolysis and inflammation.

METHODS AND RESULTS

Serial blood samples were obtained from 555 of 2,267 unstable CAD patients in the FRISC II study. Patients were treated with the LMW heparin dalteparin 120 IU kg(-1) s.c. twice daily for 5-7 days and randomized to placebo (n=285) or gender and weight-adjusted doses of dalteparin (5,000 or 7,500 IU) twice daily (n=270) for 3 months. Dalteparin persistently depressed coagulation activity with, when compared with placebo, lower median levels of factor VIIa (63 IU mL(-1) vs. 84 IU mL(-1)), prothrombin fragment 1 + 2 (0.86 nmol L(-1) vs. 1.09 nmol L(-1)) and D-dimer (21 microg L(-1) vs. 43 microug L(-1)) after 3 months, all P<0.01. Reactivation of coagulation activity was observed after cessation of both short-term and prolonged dalteparin treatment. Higher levels of tPA/PAI-1 complex (11.7 microg L(-1) vs. 6.5 microg L(-1), P<0.001) and von Willebrand factor (162% vs. 136%, P<0.001) were found during prolonged dalteparin treatment. Interleukin-6, C-reactive protein and fibrinogen levels were unaffected by dalteparin treatment.

CONCLUSIONS

Three months dalteparin treatment resulted in a sustained and pronounced reduction of coagulation activity, which corresponds to the observed reduction in death and myocardial infarction during the initial 6 weeks in the FRISC II study. The persistently elevated levels of tPA/PAI-1 complex and von Willebrand factor might reflect effects on platelets and endothelial cells and thus contribute to the gradually decreased efficacy by prolonged dalteparin treatment in unstable CAD.

Anticoagulant Therapy for Idiopathic Pulmonary Fibrosis

STUDY OBJECTIVE

To evaluate the effect of anticoagulant therapy on the survival of patients with idiopathic pulmonary fibrosis (IPF).

DESIGN

Prospective study.

SETTING

Five hospitals located in the Miyagi prefecture in Japan, including a university hospital, a Red Cross hospital, two public general hospitals, and a municipal hospital.

PATIENTS

Fifty-six patients with IPF (mean age, 69.4 years; range, 47 to 89) admitted to the hospitals from April 2001 to April 2004.

INTERVENTIONS

Patients were assigned to receive prednisolone alone or prednisolone plus anticoagulant therapy. The anticoagulants included oral warfarin in an outpatient setting and low-molecular-weight heparin for rehospitalized patients with severely progressive respiratory failure.

MEASUREMENTS AND RESULTS

There was no difference in baseline characteristics, including age, gender, clinical condition, pulmonary function, and plasma d-dimer level between the non-anticoagulant group and the anticoagulant group. The overall survival and hospitalization-free periods were assessed. There was a significant difference between survival curves of the non-anticoagulant group and the anticoagulant group, with a 2.9 hazard ratio (p = 0.04, Cox regression model). There was no significant difference in the probability of a hospitalization-free period between groups. The major cause of clinical deterioration was acute exacerbation during follow-up in the present study. Therefore, the mortality and plasma d-dimer levels in patients with an acute exacerbation were also assessed. The mortality associated with acute exacerbations of IPF in the anticoagulant group was significantly reduced compared to that in the non-anticoagulant group (18% vs 71%, respectively; p = 0.008, Fisher Exact Test). Furthermore, the plasma d-dimer levels in patients who died were significantly higher than those in survivors during acute exacerbation of IPF (3.3 +/- 2.3 microg/mL vs 0.9 +/- 0.7 microg/mL, p < 0.0001). Histologic analysis performed in three patients who died due to an exacerbation of IPF in the non-anticoagulant group demonstrated the features of usual interstitial pneumonia and acute lung injury.

CONCLUSIONS

Our data suggested that plasma d-dimer levels are associated with mortality in patients with an acute exacerbation of IPF, and that anticoagulant therapy has a beneficial effect on survival in patients with IPF.

[D-dimer levels in venous thromboembolism]

Venous thromboembolism (VTE) is associated with substantial morbidity and mortality. The clinical signs and symptoms are unspecific, widely varying from asymptomatic to sudden death. The diagnostic algorithm of VTE is an evolving field, in which D-dimers (DD) determination has been used as one of the preferred screening tests. Clinical management studies are clarifying the role of DD in the diagnostic paradigm of VTE. Published reports support the use of plasma DD determination in patients with a low clinical probability of VTE. Patients with moderate or high clinical probability of VTE show a higher probability of false negative plasma DD values. This fact forces the clinician to use more complex diagnostic test in order to either confirm or exclude VTE. A variety of different qualitative and semi-quantifiable assays are available for plasma DD determination. There is a wide variation in performance and there are discrepancies in the comparability of the different assays. Therefore, in order to both appropriately incorporate plasma DD determination in the diagnostic strategies of VTE and to reduce unnecessary investigations, clinicians should ensure that they are familiar with the diagnostic performance of the assay used in their own institution allowing a safer and cost-effective procedure.

Age related elevation of serum macrophage colony stimulating factor (M-CSF) level

We recently reported that the serum level of macrophage colony-stimulating factor (M-CSF) was elevated in patients with cerebral infarction. In the present study, we measured serum M-CSF level, as well as coagulo-fibrinolytic markers and general laboratory tests in adult healthy subjects of various ages, and investigated the relationship between age and M-CSF level. M-CSF in aged subjects (>or=65 years of age) was significantly higher than that in the younger subjects (<65 years of age), and a significant positive correlation between age and M-CSF was found. Significant positive correlations between M-CSF, and plasma levels of thrombomodulin (TM), von Willebrand factor antigen (vWF), thrombin-antithrombin III complex (TAT), prothrombin fragment 1+2 (F1+2), d-dimer products cross-linked fibrin degradation products (d-dimer) and plasmin-antiplasmin complex (PAP) were also found. Among the general laboratory tests, there was only a significant correlation between M-CSF and serum creatinine; however, no significant correlation was found between M-CSF and other tests including blood cell counts. From these results, age-related elevation of serum M-CSF level was confirmed, and was suggested not to indicate the alteration of hemopoietic condition in aged subjects but to be related to thrombotic state or systemic damaged blood vessel in the apparently healthy aged people.

LDL-Apheresis Accelerates the Recovery of Nonarteritic Acute Anterior Ischemic Optic Neuropathy

Nonarteritic acute anterior ischemic optic neuropathy (NAION) is a disabling disease which impairs visual function. It is presumed to result from disturbances of microcirculation in the anterior portion of the optic nerve head due to hemodynamic factors derived from excessive blood viscosity, or restriction of the vasal lumen in hypertensive, hypercholesterolemic, diabetic patients. We aimed to determine whether acute reduction of plasma fibrinogen and serum low-density lipoprotein (LDL) cholesterol is effective for treatment of NAION. We recruited 11 patients (7 females, 4 males) with a mean age of 57.2 +/- 19.6 years. All except one of them presented risk factors for atherosclerosis. The mean values of LDL-cholesterol and fibrinogen before treatment were 144 +/- 32 mg/dL and 341 +/- 80 mg/dL, respectively. All were treated with standard therapy (prednisone, salicylate, pentoxiphyllin) and underwent three sessions of LDL-apheresis (HELP system-B Braun) that can reduce plasma LDL-cholesterol and fibrinogen by more than 50% in a very short time. In all patients we observed a drastic reduction of LDL cholesterol and fibrinogen and a clear improvement in the visual functional data. In fact, mean values of corrected vision increased from 3.7/10 +/- 3/10 to 7.9/10 +/- 2.2/10 (P = 0.002) after the third session, while the scotomatous portion of the visual field regressed after the first session, and in 5 patients further regressed after the third session. This improvement had remained stable after 3 months. Thanks to it's effect of antagonizing hemorheologic disorders of the ocular microcirculation, fibrinogen/LDL-apheresis seems to be an efficacious treatment of NAION.

Simple and Useful Tests for Discriminating Between Acute Aortic Dissection of the Ascending Aorta and Acute Myocardial Infarction in the Emergency Setting

BACKGROUND

It is important to rapidly distinguish patients with acute aortic dissection of the ascending aorta (AADa) from those with acute myocardial infarction (AMI), because minimizing the time to initiation of reperfusion therapy leads to maximum benefits for AMI and erroneous reperfusion therapy for AADa can produce harmful outcomes. The aim of this study was to find a simple test to distinguish such patients.

METHODS AND RESULTS

Data were collected from 29 consecutive patients with AADa and 49 consecutive patients with AMI who were admitted within 4 h of the onset of symptoms. The D-dimer concentration and the ratio of the maximum upper mediastinal diameter to the maximum thoracic diameter on plain chest radiograph (M-ratio) in the emergency room were studied retrospectively. Setting the cutoff values of the D-dimer concentration and the M-ratio to 0.8 or 0.9 microg/ml and 0.309, respectively, gave a sensitivity of 93.1% and 93.1% for AADa, respectively, and a sensitivity of 91.8% and 85.7% for AMI, respectively.

CONCLUSIONS

The D-dimer value and the M-ratio, with appropriate cutoff values, have potential as tests that can be routinely used to exclude AADa patients from patients diagnosed with AMI prior to reperfusion therapy.

Role of ELISA D-dimer test in patients with unstable angina pectoris presenting at the emergency department with a normal electrocardiogram

Patients with unstable angina pectoris and acute myocardial infarction have higher than normal D-dimer levels. The aim of the study was to determine the value of the D-dimer test in patients with unstable angina pectoris and a normal electrocardiogram on presentation at the emergency department. The study sample included 81 patients who met these criteria. Blood samples collected at admission were subjected to ELISA D-dimer. Findings were correlated with coronary risk factors, use of cardiac medications, blood levels of acute phase reactants (fibrinogen and C-reactive protein), cardiac enzymes levels, length of hospital stay, and catheterization findings. ELISA D-dimer levels were statistically significantly correlated with cardiac risk factors, namely male sex, older age, smoking, and hypertension (r = 0.25, P = 0.02; r = 0.43, P = 0.0001; r = 0.26, P = 0.03; r = 0.35, P = 0.002, respectively), in addition to use of cardiac medications (beta blockers, aspirin, nitrates), levels of acute phase reactants, length of stay, and catheterization findings. On multivariate analysis, only D-dimer level, age, and sex were predictors of length of stay (P = 0.018). The study suggests that D-dimer levels at admission to the emergency department may serve as an additional tool to predict the magnitude of unstable angina pectoris in patients with a normal electrocardiogram.

Determinants of ELISA D-dimer sensitivity for unstable angina pectoris as defined by coronary catheterization

Unstable angina pectoris is associated with elevated D-dimer levels. However, the operating characteristics (sensitivity, specificity, positive and negative predictive value) of the D-dimer assay for the diagnosis of coronary artery disease (CAD) are unknown. Using a prospective, observational design, we collected blood from 54 patients with unstable angina pectoris at admission and assayed for ELISA D-dimer levels. The sensitivity, specificity, and negative and positive prediction values for angiographically determined coronary artery disease were calculated at multiple discriminate levels. All patients underwent coronary catheterization. A statistically significant correlation was noted between ELISA D-dimer levels and age, male sex, hypertension, use of beta-blocker, fibrinogen levels and catheterization findings. No correlation was noted between ELISA D-dimer levels and degree of the coronary artery disease. Best results were provided at a discriminate level of 270 ng/ml, with sensitivity 70%, negative predictive value 72%, and overall accuracy 67%. All discriminate levels, however, provided values too low for diagnosis. In conclusion, ELISA D-dimer assay is a non-sensitive, non-specific test for coronary artery disease as defined by coronary catheterization. However, the assay adds information regarding the severity of disease in patients presenting with acute coronary syndrome.

Activation of the inflammation, coagulation, and fibrinolysis systems, without influence of abciximab infusion in patients with non-ST-elevation acute coronary syndromes treated with dalteparin: a GUSTO IV substudy

BACKGROUND

In acute coronary syndromes, the inflammation and the coagulation systems are activated, implying an impaired outcome. In addition to platelet inhibition, recent evidence suggests that the glycoprotein IIb/IIIa receptor inhibitor abciximab attenuates inflammation and coagulation activity.

METHODS

The Swedish Global Utilization of Strategies To open Occluded arteries-IV (GUSTO-IV) substudy included 404 patients with non-ST-elevation acute coronary syndromes. In addition to aspirin and dalteparin, all patients were randomized to receive abciximab infusion for 24 hours or 48 hours or corresponding placebo without early coronary revascularization. Plasma samples were obtained at baseline and 24, 48, and 72 hours.

RESULTS

The median levels of the coagulation markers thrombin/antithrombin complex and soluble fibrin increased significantly from 3.1 to 3.7 ug/L (baseline to peak; P <.001) and from 20 to 23 nmol/L (P <.001), respectively. The fibrinolysis marker, tissue plasminogen-activator, also increased its median levels, from 11.7 to 17.5 ug/L (P <.001), whereas the median level of plasminogen-activator-inhibitor was unchanged. The inflammatory markers interleukin-6, C-reactive protein, and fibrinogen also increased their median levels (5.4-7.8 ng/L, P <.001; 4.4-8.7 mg/L, P <.001; 3.3-3.9 g/L, P <.001). However, there were no differences in median levels or in changes of median levels of any marker at any point between the placebo group and any of the abciximab groups.

CONCLUSIONS

In non-ST-elevation acute coronary syndrome, there was a simultaneous activation of the inflammation, coagulation, and fibrinolysis systems, despite aspirin and dalteparin treatment. Prolonged treatment with abciximab had no influence of the activation of these systems.

Coagulation, inflammation and myocardial dysfunction in unstable coronary artery disease and the influence of glycoprotein IIb/IIIa inhibition and low molecular weight heparin

Patients with unstable coronary artery disease (CAD) have an increased risk of subsequent myocardial infarction and death. This study evaluated the safety and efficacy of treatment with glycoprotein IIb/IIIa inhibition in addition to aspirin, low molecular-weight heparin and its influence on coagulation and inflammation. Also, early and differentiated risk assessment utilising markers of inflammation, myocardial damage and dysfunction were evaluated. The Global Utilisation of Strategies To open Occluded arteries-IV (GUSTO-IV) trial randomised 7800 patients with unstable CAD to 24 or 48 hours infusion of abciximab or placebo in addition to routine treatment with aspirin and heparin or dalteparin. Baseline levels of creatinine, C-reactive protein (CRP), troponin T (TnT) and N-terminal pro-brain natriuretic peptide (NT-proBNP) were analysed. At selected sites, all patients received subcutaneous dalteparin (n=974), in stead of heparin infusion (n=6826). In a sub-population of dalteparin treated patients (n=404), serial measurements of markers of coagulation, fibrinolysis and inflammation were also performed. Addition of abciximab to dalteparin as the primary treatment of unstable CAD was not associated with any significant reduction in cardiac events but a doubled risk of bleedings. The combination of abciximab with dalteparin seemed as safe when used with heparin. Despite full dose dalteparin and aspirin there was a simultaneous activation of the inflammation, coagulation and fibrinolysis systems without any influence of the abciximab treatment. Elevated levels of CRP, TnT, and NT-proBNP and reduced creatinine clearance were independently related to short and long-term mortality. The best prediction of high and low risk was provided by a combination of NT-proBNP and creatinine clearance. Any detectable elevation of TnT and reduced creatinine clearance, but neither elevation of CRP nor NT-proBNP, were also independently associated to a raised risk of subsequent myocardial infarction.