Activated coagulation/fibrinolysis system and platelet function in acute thrombotic stroke patients with increased C-reactive protein levels

Clinical Significance and Dynamic Change of Coagulation Parameters in Ischemic Stroke Patients Treated with Intravenous Thrombolysis

Objective

Investigations on coagulation parameters including fibrinogen (Fbg), fibrinogen degradation products (FDP), and D-dimer in ischemic stroke patients treated with intravenous thrombolysis are insufficient. We aimed to investigate the association between in-hospital clinical outcomes and the coagulation parameters at different time points in ischemic stroke patients treated with intravenous tissues plasminogen activator (IV tPA).

Methods

We retrospectively enrolled patients who received IV tPA therapy within 4.5 h from symptoms onset. Demographics, clinical characteristics, imaging measures, and the discharge mRS score were collected. Multivariable logistic regression analyses were performed to test whether coagulation parameters were independent predictors for the in-hospital clinical outcomes. We also employed machine learning models to investigate whether coagulation parameters were able to improve the prediction of favorable functional outcomes.

Results

One hundred and fifty-two patients treated with IV tPA were included. Among the coagulation parameters, low D-dimers at 48 h proved to be an independent predictor of favorable functional outcome (adjusted odd ratio 0.24, 95% confidential intervals 0.06-0.92, P  =  0.04). The AUC of D-dimer at 48 h to predict favorable functional outcome was 0.73 (0.60-0.87) and the optimal cut-off value was 0.92 (sensitivity 0.69, specificity 0.78). Machine learning models with D-dimer at 48 h had superior performance in predicting favorable functional outcomes and among the input variables in the machine learning models, D-dimer at 48 h showed the highest weight in predicting mRS 0-1 at discharge (38.44%).

Conclusion

Increased levels of D-dimer at 48 h was associated with lower proportion of favorable functional outcomes in acute ischemic stroke patients with intravenous thrombolysis.

Association Between High-Sensitivity C-Reactive Protein and Prognosis of Patients with Acute Cerebral Infarction

PURPOSE

To investigate the association of serum high-sensitivity C-reactive protein (hs-CRP) with the severity of neurological deficits and prognosis in patients with acute cerebral infarction (ACI).

PATIENTS AND METHODS

In this retrospective analysis, 119 patients with ACI were recruited from January to December 2020. The serum hs-CRP level was measured by a latex-enhanced immunoturbidimetric assay. The severity of neurological deficits and prognosis of ACI patients were assessed using the National Institutes of Health Stroke Scale (NIHSS) and the modified Rankin Scale (mRS). Multivariate logistic analysis was performed and receiver operating characteristic (ROC) curves were plotted to evaluate the value of hs-CRP in predicting the prognosis of ACI.

RESULTS

The patients with a more favorable prognosis (mRS score 0-2) had a lower median serum hs-CRP level than those with a worse prognosis (mRS score 3-6) (3.32 IQR: 1.51, 8.04 to 17.93 IQR:16.02, 19.01; P<0.001). After adjusting for potential confounders, multivariable linear regression showed that serum hs-CRP level was independently associated with NIHSS score (Beta = 0.952, P<0.001) and mRS score (Beta=0.878, P<0.001). Multivariate logistic analysis revealed that high hs-CRP level was an independent predictor of the poor prognosis in patients with ACI (adjusted¹ OR = 1.995; 95% CI = 1.499-2.655; adjusted² OR = 2.75; 95% CI = 1.015-7.457). ROC curve analysis indicated that the area under the curve for hs-CRP to predict poor prognosis was 0.986. The cutoff value, sensitivity, and specificity were 11.835 mg/L, 95%, and 92.5%, respectively. In terms of ischemic stroke subtypes, the serum hs-CRP level was higher in large-artery atherosclerosis (LAA) patients than in those with small-artery occlusion (SAO) and cardioembolism (CE). In addition, the patients with LAA had higher scores of NIHSS and mRS than those with SAO and CE.

CONCLUSION

Serum hs-CRP level is an independent predictor of prognosis, and an efficient index to discriminate patients with ACI, especially for those with LAA.

The prothrombotic state in cancer

Neoplasms result from changes in the mechanisms of growth, differentiation, and cellular death. Cancers are of high clinical relevance due to their prevalence and associated morbidity and mortality. The clinical and biological diversity of cancer depends mainly on cellular origin and degree of differentiation. These changes result from alterations in molecular expression that generate a complex clinical, biochemical, and morphologic phenotype. Although cancer is associated with a hypercoagulable state, few cancers result in a thrombotic event. Many factors influence thrombotic incidence, such as advanced disease, central catheter placement, chemotherapy, neoplasia, and surgery. The pro-coagulant state is associated with anomalies in the vascular wall, blood flow, blood constituents (tissue factor, thrombin), coagulation state, and cell growth factors. Tumor cells perpetuate this phenomenon by releasing tissue factor, inflammatory cytokines, and growth factors. These changes favor cellular activation that gives rise to actions involving coagulation, inflammation, thrombosis, tumor growth, angiogenesis, and tumor metastases. These, in turn, are closely linked to treatment response, tumor aggressiveness, and host survival. Activation of the coagulation cascade is related to these phenomena through molecules that interact in these processes. As such, it is necessary to identify these mediators to facilitate treatment and improve outcomes.

Psoriatic disease is associated with systemic inflammation, endothelial activation, and altered haemostatic function

Psoriasis is a chronic, immune-mediated inflammatory skin disease, affecting approximately 2% of the general population, which can be accompanied by psoriatic arthritis (PsA). The condition has been associated with an increased cardiovascular burden. Hypercoagulability is a potential underlying mechanism that may contribute to the increased risk of major cardiovascular events in psoriatic individuals. Whole blood samples were collected from 20 PsA patients and 20 healthy individuals. The concentrations of inflammatory molecules (C-reactive protein, serum amyloid A, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and soluble P-selectin) were determined by enzyme-linked immunosorbent assays. In addition, clotting efficiency was evaluated by thromboelastography. The fibrin network architecture was also assessed by scanning electron microscopy. Elevated levels of circulating inflammatory molecules were significantly associated with the presence of psoriatic disease. Furthermore, an increased tendency towards thrombus formation was significantly predictive of disease presence. Scanning electron microscopy revealed that fibrin clots were denser in psoriatic individuals, compared to healthy controls, with an increased fibrin fibre diameter associated with psoriatic disease. Our results add to the accumulating evidence of the systemic nature of psoriasis and the subsequent risk of cardiovascular comorbidities, potentially due to an acquired hypercoagulability. We suggest that haemostatic function should be monitored carefully in psoriatic patients that present with severe disease, due to the pre-eminent risk of developing thrombotic complications.

Evaluation of analytic and clinical performance of thrombin-antithrombin complex and D-dimer assay in prognosis of acute ischemic stroke

: To evaluate analytic and clinical performance of plasma thrombin-antithrombin complex (TAT) and D-dimer assay in assessing the severity and outcome of acute ischemic stroke. The prospective study was conducted and extended from January 2018 to December 2018. A total of 236 patients admitted within 24 h after neurologic symptoms onset were recruited. The median TAT and D-dimer levels were significantly higher in the acute ischemic stroke patients than in the controls. The average TAT levels in patients with mild, moderately severe and severe stroke were 1.75 [interquartile ranges (IQR), 1.1-2.6], 3.3 (IQR, 1.8-4.5) and 13.5 (IQR, 7.2-15.3) ng/ml. The D-dimer levels of respective patient groups were 0.39 (IQR, 0.22-0.73), 0.58 (IQR, 0.39-1.25) and 3.59 (IQR, 1.73-4.74) mg/l. With the optimal cut-off TAT level (1.75 ng/ml) determined from receiver operating characteristic analysis, the Area under the curve (AUC), the sensitivity and specificity of TAT for stroke diagnosis were 0.763, 58.1 and 87.8%. The cut-off D-dimer level was 0.38 mg/l and the AUC, the sensitivity and specificity were 0.772, 60.2 and 88.9%. The Area under the receiver operating characteristic curves (AUROCs) and sensitivity in the moderate to severe stroke increased to 0.903 and 86.9% for TAT, and 0.880 and 80.3% for D-dimer, respectively. Age and high TAT level were significant independent risk factors for stroke severity. Age, high initial National Institutes of Health Stroke Scale score and high TAT level were significant independent poor prognostic factors on multivariate analysis. TAT and D-dimer were superior in separating the moderate-to-severe stroke than mild stroke. A high TAT plasma level is an independent predictor for stroke severity and poor prognosis during 1-month follow-up.

The Value of Combined Detection of D-dimer and CD62p in Judging the Severity of Acute Cerebral Infarction and Short-Term Prognosis

Objective

To explore the value of combined detection of peripheral blood P-selectin (CD62p) and D-dimer (D-dimer) in the judgment of acute cerebral infarction severity and short-term prognosis.

Methods

268 patients with acute cerebral infarction from February 2015 to February 2019 were selected as the observation group. According to the National Institute of Health stroke scale, there were 90 cases (SCI group), 88 cases (MOCI group), and 90cases (MICI group) in the severe, moderate, and mild cerebral infarction groups, respectively. In the same period, 80 cases of healthy people served as the Normal group. Use flow cytometry to detect CD62p in peripheral blood and magnetic bead method to detect D-dimer level within 24 hours of onset. Logistic regression was used to analyze whether the two are factors affecting the short-term prognosis of acute cerebral infarction, and the ROC curve was drawn to evaluate the value of the combined detection of the two in the short-term prognosis of patients with acute cerebral infarction.

Results

Peripheral blood D-dimer and CD62p levels (2.95 ± 0.76 ng/l, 34.03 ± 5.29 ng/l) in the SCI group were higher than those in the MOCI group (2.30 ± 0.51 ng/l, 27.58 ± 5.56 ng/l) and the MICI group (1.87 ± 0.40 ng/l, 19.60 ± 3.98 ng/l); the difference between the groups was statistically significant (P < 0.05). Logistic regression analysis showed that D-dimer and CD62p were independent risk factors affecting the poor prognosis of patients with acute cerebral infarction (OR values were 3.752 and 1.213, and 95% CI were 1.612-7.934 and 1.093-1.342, respectively, both P < 0.05). The AUC of D-dimer combined with CD62p for predicting poor prognosis of acute cerebral infarction is 0.859, which is better than D-dimer and CD62p alone.

Conclusion

Peripheral blood D-dimer combined with CD62p detection is helpful for the risk stratification and short-term prognosis assessment of patients with acute cerebral infarction. Clinical detection is of great significance for the prevention and monitoring of disease development.

Association of Level and Increase in D-Dimer With All-Cause Death and Poor Functional Outcome After Ischemic Stroke or Transient Ischemic Attack

Background

D‐dimer is involved in poor outcomes of stroke as a coagulation biomarker. We aimed to investigate the associations of the level and increase in D‐dimer between baseline and 90 days with all‐cause death or poor functional outcome in patients after ischemic stroke or transient ischemic attack.

Methods and Results

We collected data from the CNSRIII (Third China National Stroke Registry) study. The present substudy included 10 518 patients within 7 days (baseline) of ischemic stroke or transient ischemic attack and 6268 patients at 90 days. Poor functional outcome at 1 year was assessed on the basis of the modified Rankin Scale (≥3). Multivariable Cox regression or logistic regression was used to assess the association of D‐dimer levels with all‐cause death or poor functional outcome. D‐dimer levels at 90 days were lower than those at baseline (1.4 µg/mL versus 1.7 µg/mL; P<0.001). Higher baseline D‐dimer level was associated with all‐cause death (adjusted hazard ratio [HR], 1.77; 95% CI, 1.25–2.52; P=0.001) and poor functional outcome (adjusted odds ratio [OR], 1.49; 95% CI, 1.23–1.80; P<0.001) during 1‐year follow‐up. Higher D‐dimer level at 90 days was also associated with poor outcomes independently. Furthermore, an increase in D‐dimer levels between baseline and 90 days was associated with all‐cause death (since 90 days to 1 year after index event) (adjusted HR, 1.99; 95% CI, 1.12–3.53; P=0.019) but not with poor functional outcome (adjusted OR, 1.08; 95% CI, 0.82–1.41).

Conclusions

Our study shows that high level and an increase in D‐dimer between baseline and 90 days are associated with poor outcomes in patients after ischemic stroke or transient ischemic attack.

Association of lung function with cardiovascular risk: a cohort study

BACKGROUND

The potential effects of pulmonary dysfunction on cardiovascular diseases (CVD) are receiving attention. We aimed to investigate and quantify the cross-sectional and longitudinal associations between lung function and overall cardiovascular risk among Chinese general population.

METHODS

We studied 4019 participants from the Wuhan-Zhuhai cohort, with a follow-up of 3 years. A multivariable risk algorithm generated from the Framingham study was used to calculate individuals' overall cardiovascular risk i.e. 10-Year CVD Risk, which was further classified into 2 categories: low (< 10%) and high (≥10%) CVD risk. General linear model and logistic regression model were separately used to assess the associations of lung function with continuous and dichotomous 10-Year CVD Risk.

RESULTS

Cross-sectionally, each 5% decrease in FEV₁/FVC was associated with a 0.47% increase in 10-Year CVD Risk (P < 0.001). The adjusted odds ratio (OR) (95% confidence interval [CI]) for the prevalence of high CVD risk (10-Year CVD Risk≥10%) was 1.12 (1.07, 1.17) corresponding to each 5% decrease in FEV₁/FVC. The OR (95% CI) for high CVD risk in the lowest group of FEV₁/FVC (< 70% i.e. chronic obstructive pulmonary disease [COPD]) was 2.37 (1.43, 3.91) when compared with the highest group. Longitudinally, the adjusted risk ratio (RR) (95% CI) for the incidence of high CVD risk was 1.14 (1.03, 1.25) with each 5% decrease in baseline FEV₁/FVC. Compared with the highest group of FEV₁/FVC, the RR (95% CI) for high CVD risk in the lowest group (COPD) was 4.06 (1.46, 11.26). Analyses of 10-Year CVD Risk with FVC or FEV₁ showed similar trends and significant associations (all P < 0.05).

CONCLUSION

Reduced lung function was cross-sectionally and longitudinally associated with increased cardiovascular risk in Chinese general population.

Exposure to hypoglycemia and risk of stroke

In the treatment of both type 1 and type 2 diabetes mellitus, maintaining a euglycemic state represents one of the key challenges. Improper dosing and administration of glucose-lowering drugs is associated with an increased risk of recurrent hypoglycemia episodes. In addition, the risk of adverse cardiovascular events in diabetic patients, particularly myocardial infarctions and strokes, is well established. Current research indicates a potential link between the baseline risk of cardio/cerebrovascular events in diabetic patients and exposure to hypoglycemia. In this review of the literature, we aim to determine if a relationship exists between recurrent hypoglycemia and adverse neurovascular events.

COPD and stroke: are systemic inflammation and oxidative stress the missing links?

Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation and loss of lung function, and is currently the third largest cause of death in the world. It is now well established that cardiovascular-related comorbidities such as stroke contribute to morbidity and mortality in COPD. The mechanisms linking COPD and stroke remain to be fully defined but are likely to be interconnected. The association between COPD and stroke may be largely dependent on shared risk factors such as aging and smoking, or the association of COPD with traditional stroke risk factors. In addition, we propose that COPD-related systemic inflammation and oxidative stress may play important roles by promoting cerebral vascular dysfunction and platelet hyperactivity. In this review, we briefly discuss the pathogenesis of COPD, acute exacerbations of COPD (AECOPD) and cardiovascular comorbidities associated with COPD, in particular stroke. We also highlight and discuss the potential mechanisms underpinning the link between COPD and stroke, with a particular focus on the roles of systemic inflammation and oxidative stress.

Serum C-reactive protein, fibrinogen and D-dimer in patients with progressive cerebral infarction

OBJECTIVE

Progressive cerebral infarctions increase mortality and functional disability through mechanisms which have yet to be completely understood. The goal of this study was to explore the dynamic changes of serum C-reactive protein (CRP), fibrinogen (FIB) and D-dimer (D-D) in order to better characterize progressive cerebral infarction.

METHODS

The amount of serum CRP, FIB and D-D was measured in 82 patients with progressive cerebral infarction by taking samples from the internal carotid artery (progressive group), and in 186 patients with non-progressive cerebral infarction (non-progressive group) by using an automatic biochemical analyzer during the next day (day 1), day 3, day 7, and day 14 after being admitted to hospital. Carotid vascular ultrasound and neurological deficit score (National Institutes of Health Stroke Scale, NIHSS) were also recorded.

RESULTS

Carotid stenosis ratio was significantly higher in the progressive group than in the non-progressive group (P < 0.01) on admission. In the progressive group, CRP increased significantly on day 3, followed by a decline on day 7 and day 14, but was significantly higher than those in the non-progressive group (P < 0.01). The levels of FIB and D-D increased in the progressive group more than those in the non-progressive group on day 3, day 7, and day 14 (P < 0.01). The progressive group patients' NIHSS score gradually increased after admission, which was opposite to the non-progressive group patients whom followed a downward trend. The difference between these two groups was significant (P < 0.01).

CONCLUSION

Observing changes of CRP, FIB and D-D may contribute to early identification and timely treatment of progressing ischemic strokes.

Relationship between Inflammation and Aspirin and Clopidogrel Antiplatelet Responses in Acute Ischemic Stroke

OBJECTIVE

We measured serum levels of proinflammatory/prothrombotic markers P-selectin, CD40L, matrix metalloproteinase 9 (MMP-9), intracellular adhesion molecule 1 (ICAM-1), and interleukin (IL)-6 in ischemic stroke patients, correlating their levels with the results of aspirin (ASA) and clopidogrel antiplatelet responses, using 3 "point of care" platelet function instruments, thromboelastograph (TEG), Accumetrics (ACU), and impedance aggregometer (IMP).

METHODS

Patients on chronic ASA regimen at the time of stroke were switched to 300 mg clopidogrel loading dose and 75 mg clopidogrel maintenance dose. Serum levels of the aforementioned inflammatory mediators were measured in 51 patients at baseline (on ASA regimen), and at 26 ± 5 hours and 64 ± 18 hours postclopidogrel administration by enzyme-linked immunosorbent assay.

RESULTS

P-selectin, CD40L, and MMP-9 serum levels were reduced; ICAM-1 and IL-6 serum levels showed no difference postclopidogrel administration relative to baseline. Patients' stratification based on ASA dose showed more significant reductions in P-selectin, CD40L, and MMP-9 serum levels postclopidogrel administration in patients who were on baseline 81 mg ASA, as compared to patients on 325 mg ASA. Measurement with TEG was sensitive for correlating ASA antiplatelet responses to serum levels of inflammatory markers, whereas measurements with ACU and IMP were sensitive for correlating clopidogrel antiplatelet responses to serum levels of inflammatory markers.

CONCLUSION

Clopidogrel exerts both platelet-dependent and platelet-independent anti-inflammatory effects. The association between platelet function and inflammation depends on the platelet function analyzer, the type of antiplatelet agent, the nature of the inflammatory marker, and the time of measurement relative to the time of drug administration.

The association between mean platelet volume and chronic atrial fibrillation and the presence of thrombotic events

Mean platelet volume (MPV), a marker of platelet activation, is a surrogate marker of platelet function and a potential mediator of the association between inflammation and thrombosis. The present retrospective study sought to investigate the association between MPV and the presence of thrombotic events (TEs) in patients with chronic atrial fibrillation (AF). A total of 114 consecutive patients with chronic AF were enrolled from a Chinese hospital. Individuals were divided into three groups: The AF+TE group (n=57, 33.1%), which comprised patients in AF with concomitant TEs; the AF group (n=57, 33.1%), which comprised patients in AF with no identifiable TEs, as confirmed by brain computed tomography, transesophageal echocardiography, or a combination of the two; and a control group (n=58, 33.7%), which consisted of patients who were in sinus rhythm. MPV, high-sensitivity C-reactive protein (hsCRP), D-dimer and the left atrial diameter (LAD) were analyzed in the 172 participants. The MPV level of patients in the AF+TE group was significantly higher than that of patients in the AF and control groups (P<0.05). In the correlation analysis, MPV levels were found to be positively correlated with LAD, D-dimer concentrations and hsCRP levels in patients with AF (r=0.960, P<0.05; r=0.896, P<0.05; and r=0.924, P<0.01, respectively). In the receiver operating characteristic curve analysis, the value for MPV levels required to detect TEs with a sensitivity of 77.5% and specificity of 78% was 10.5 femtoliter (fl). A high MPV level (>10.5 fl) was significantly associated with the occurrence of TEs (odds ratio, 3:1; 95% confidence interval, 1.6-5.1; P=0.000). The results of the present study suggest that an additional biomarker, MPV, has a predictive value for the presence of TEs in patients with AF. MPV may be a potential mediator between inflammation and thrombosis.

C-reactive protein, cardiovascular disease and stroke: new roles for an old biomarker

Stroke is a leading cause of death and disability worldwide. A new and exciting development in cardiovascular disease is the recognition of the role of inflammation in atherosclerosis. C-reactive protein, an acute phase reactant, appears to be a promising biomarker for cardiovascular disease, possibly more predictive than cholesterol and also may play an etiological role. C-reactive protein also appears to be predictive of stroke risk, although less so in the elderly. Although the number of studies on stroke (apart from cardiovascular disease) is limited, there is a significant graded increase in stroke risk within the low-to-high normal range of C-reactive protein. C-reactive protein is readily amenable to treatment with anti-inflammatory drugs, such as aspirin and statins. New and increasingly available high-sensitivity assays may make C-reactive protein a standard screening tool for cardiovascular disease.

Biomarkers for stroke

Background

Major stroke clinical trials have failed during the past decades. The failures suggest the presence of heterogeneity among stroke patients. Biomarkers refer to indicators found in the blood, other body fluids or tissues that predicts physiologic or disease states, increased disease risk, or pharmacologic responses to a therapeutic intervention. Stroke biomarkers could be used as a guiding tool for more effective personalized therapy.

Main Contents

Three aspects of stroke biomarkers are explored in detail. First, the possible role of biomarkers in patients with stroke is discussed. Second, the limitations of conventional biomarkers (especially protein biomarkers) in the area of stroke research are presented with the reasons. Lastly, various types of biomarkers including traditional and novel genetic, microvesicle, and metabolomics-associated biomarkers are introduced with their advantages and disadvantages. We especially focus on the importance of comprehensive approaches using a variety of stroke biomarkers.

Conclusion

Although biomarkers are not recommended in practice guidelines for use in the diagnosis or treatment of stroke, many efforts have been made to overcome the limitations of biomarkers. The studies reviewed herein suggest that comprehensive analysis of different types of stroke biomarkers will improve the understanding of individual pathophysiologies and further promote the development of screening tools for of high-risk patients, and predicting models of stroke outcome and rational stroke therapy tailored to the characteristics of each case.

Role of C-reactive protein, D-dimer, and fibrinogen levels in the differential diagnosis of central and peripheral vertigo

Vertigo is encountered frequently in emergency services. Researchers have explored the role of serologic markers in the differentiation of central and peripheral vertigo. The study reported here was designed to evaluate the diagnostic efficacy of serologic markers (fibrinogen, D-dimer, and C-reactive protein [CRP]) in the differential diagnosis of peripheral and central vertigo. A total of 116 patients who sought treatment for vertigo at Gazi University Hospital Adult Emergency Services during a 3-mo period were included in the study. CRP, fibrinogen, and D-dimer levels were assessed in an effort to differentiate between cases of peripheral and central vertigo. In all, 65.5% of patients (76 patients) were women. Patients younger than 50 y of age accounted for 60.3% (70 patients). The average D-dimer level for the entire group of patients was 181.9+/-132.2 microg/mL, the average CRP level, 4.2+/-8.4 mg/L, and the average fibrinogen level, 421.9+/-176.0 mg/dL. Although serum D-dimer, fibrinogen, and CRP values appeared to be higher in patients with central vertigo than in those with peripheral vertigo, no statistically significant differences were noted between the 2 groups in terms of these 3 parameters (P>.05). When 6 mg/L was used as the cutoff point for CRP and 320 mg/dL was used for fibrinogen, the numbers of patients with CRP and fibrinogen levels higher than these values were significantly higher for central vertigo than for peripheral vertigo (P<.05). The present study shows that blood D-dimer, fibrinogen, and CRP levels cannot be significant markers for the differentiation of central and peripheral vertigo.

Acetylsalicylic acid is compounding to antiplatelet effect of C-reactive protein

The contribution of inflammatory process to the modulation of platelet response to acetylsalicylic acid (ASA) remains obscure. In our study, we examined the in vitro effect of C-reactive protein (CRP) on the ASA-mediated inhibition of collagen-stimulated platelet reactivity. Influence of CRP on platelet responsiveness to ASA was analysed using classical turbidimetric aggregation and flow cytometry. When acting alone, both C-reactive protein and ASA inhibited collagen-dependent platelet aggregation and reduced the expressions of two platelet surface membrane activation markers: P-selectin and activated GPIIbIIIa complex. Compared to the effects observed for ASA alone, the simultaneous action of both agents lead to further reductions in platelet aggregation (by 56.7+/-1.0% vs. 14.9+/-0.6%, p<0.0001) and lowered the expressions of platelet surface membrane P-selectin (by 72.1+/-5.3% vs. 65.0+/-6.0%, p<0.01) and activated GPIIbIIIa (by 67.0+/-5.6% vs. 47.7+/-8.3%, p<0.01). In general, our findings showed for the first time the augmenting effect of native C-reactive protein in the antiplatelet action of acetylsalicylic acid. Thus, we conclude that the effectiveness of aspirin therapy may strongly depend upon the presence of native CRP in circulation.

Randomized comparison of the effects of ASA plus clopidogrel versus ASA alone on early platelet activation in acute coronary syndromes with elevated high-sensitivity C-reactive protein and soluble CD40 ligand levels

BACKGROUND

High-sensitivity C-reactive protein (hsCRP) and soluble cluster of differentiation 40 ligand (sCD40L) have been established as effective markers of inflammation in predicting the risk for adverse outcomes in patients with acute coronary syndromes (ACSs). Activated platelets secrete certain inflammatory mediators such as P-selectin and sCD40L, which play a role in the pathogenesis of ACSs. Although acetylsalicylic acid (ASA) has been found to be an effective treatment of ACSs, the addition of clopidogrel bisulfate has been found tofurther improve clinical outcomes as a result of additional antiplatelet and anti-inflammatory action. Few data exist concerning the effects of dual antiplatelet therapy on these markers in patients with ACSs.

OBJECTIVE

The aim of this study was to assess the effectiveness and clinical significance of clopidogrel administration in patients with ACSs without ST segment elevation treated with ASA.

METHODS

This randomized, single-blind, controlled trial was conducted at the First Department of Cardiology, Hippokration Hospital, Athens, Greece. Inpatients aged>or=21 years with ACSs without ST segment elevation were randomly assigned to 1 of 2 groups: ASA 325 mg/d for 1 week, followed by ASA (100 mg/d) plus clopidogrel (300-mg loading dose followed by 100 mg/d) for 36 weeks (ASA+Clop group) or ASA alone (325 mg/d for 1 week, followed by 75 mg/d for 36 weeks) (ASA group). Levels of serum sCD40L, hsCRP, and P-selectin were determined on admission and at 8 hours, 48 hours, and 6 days of treatment. By means of clinical follow-up, Kaplan-Meier free-of-major adverse cardiovascular events (MACES) plots were used to assess the prevalence of MACES, including cardiovascular-related death, in patients with and without high levels of hsCRP (>or=3 mg/L) and sCD40L (>or=5 microg/L) for 52 weeks.

RESULTS

A total of 86 patients were enrolled (71 men, 15 women; mean [SD] age, 68 [3] years; mean [SD] weight, 86 [18] kg; white race, 86 [100%]; 43 patients per group). Both groups had similar initial clinical characteristics and P-selectin levels. Baseline hsCRP and sCD40L levels were correlated with baseline P-selectin levels (hsCRP, r2=0.099

CONCLUSIONS

The results of this small study suggest that early activation of platelets, as measured using P-selectin levels, was effectively inhibited by the addition of clopidogrel to a regimen of ASA in the subgroup of patients with ACSs and intense activation of platelets (defined as high hsCRP and sCD40L levels). In patients without high hsCRP and sCD40L levels, the addition of clopidogrel did not have a significant effect on P-selectin levels.

Oxidative stress during the chronic phase after stroke

Stroke is a complex disease originating and developing on the background of genetic predisposition and interaction between different risk factors that chronically damage blood vessels. The search for an effective treatment of stroke patients is the main priority of basic and clinical sciences. The chronic phase of stroke provides possibilities for therapy directed toward stimulation of recovery processes as well as prophylaxis, which reduces the probability of subsequent cerebrovascular events. Oxidative stress is a potential contributor to the pathophysiological consequences of stroke. The aim of the present review is to summarize the current knowledge of the role of oxidative stress during the chronic phase after stroke and its contribution to the initiation of subsequent stroke. The relationship among inflammation, hemostatic abnormalities, and platelet activation in chronic stroke patients is discussed in the context of ongoing free radical processes and oxidative damage. Free radical-mediated effects of increased plasma level of homocysteine and its possible contribution to the processes leading to recurrent stroke are discussed as well. The status of the antioxidant defense system and the degree of oxidative damage in the circulation of stroke survivors are examined. The results are interpreted in view of the effects of the vascular risk factors for stroke that include additional activation of inflammatory and free radical mechanisms. Also, the possibilities for combined therapy including antioxidants in the acute and convalescent stages of stroke are considered. Future investigations are expected to elucidate the role of free radical processes in the chronic phase after stroke and to evaluate the prophylactic and therapeutic potential of anti-radical agents.

Inflammation, blood pressure, and stroke: an opportunity to target primary prevention?

Promising findings suggest that systemic inflammation and neuroinflammation are central features in cerebrovascular disease. Inflammatory mechanisms are also important participants in the pathophysiology of hypertension. Markers of inflammation have been shown to be upregulated in different forms of cerebrovascular disease, and to correlate with vascular risk. The inhibitor nuclear factor-kB/nuclear factor-kB system is considered a major intracellular inflammatory pathway, mediating most of the vascular inflammatory responses. Increasing evidence indicates that hypertension, through the vasoactive peptides angiotensin and endothelin-1, promotes and accelerates the atherosclerotic process via inflammatory mechanisms. Proinflammatory properties of angiotensin II have been demonstrated. The identification of useful markers of inflammation, of new therapeutic targets to interfere with these mechanisms, and the evaluation of the efficacy of anti-inflammatory treatments will allow progress in our ability to combat cerebrovascular disease and the complications of hypertension. Whether these targets will be useful in the development of risk prediction strategies or therapies for the treatment of stroke in humans is far from clear.

Assessment of Acute Phase Proteins in Acute Ischemic Stroke

Acute phase proteins (APPs) have been implicated to play important roles during both acute and chronic inflammatory processes in different diseases including ischemic stroke. Though there are several studies showing the importance of APPs as inflammation markers in acute ischemic stroke (AIS), the time course of these proteins during acute phase of AIS is not well known. Thus, the aim of this study was to show the changes in plasma levels of six APPs (i.e., haptoglobin [Hp], ceruloplasmin [Cp], high-sensitive C-reactive protein [h-CRP], fibrinogen, complement 3 [C3] and complement 4 [C4]) during the first 10 days after acute stroke. The study group consisted of 34 female and 19 male patients (n = 53; mean age 65 +/- 12 years), who had first acute ischemic stroke (AIS). An age-matched control group (n = 53; 32 female and 21 male subjects, mean age 62 +/- 6 years) was also included. To evaluate the plasma levels of six APPs, the blood samples of patients with AIS were withdrawn on admission (day 1), and after 3, 5 and 10 days, whereas only one measurement was performed in the control group. In addition, several cerebrovascular risk factors were determined. The peak levels of APPs were higher in the AIS group than the control group (p < 0.0001). In serial measurements, the levels of h-CRP, Hp, C3 and C4 showed alterations during 10 days after AIS (p < 0.0001, p < 0.05, p < 0.0001, p < 0.0001, respectively). The alterations in levels of fibrinogen and Cp were not statistically significant (p > 0.05). After stroke, h-CRP, C3 and fibrinogen reached their highest values on the third day, Cp and C4 on the fifth day, and Hp on the tenth day. The plasma levels of h-CRP correlated positively with other five APPs studied (p < 0.05). These findings support the importance of inflammation processes after stroke. We suggest that the differences in levels of APPs could be used in predicting the outcome of stroke patients.

Hemostatic Function and Progressing Ischemic Stroke

BACKGROUND AND PURPOSE

Early clinical progression of ischemic stroke is common and is associated with increased risk of death and dependency. We hypothesized that activation of the coagulation system is an important contributor in some cases of deterioration. We aimed to characterize alterations in circulating hemostatic markers in patients with progressing stroke.

METHODS

Consecutive acute ischemic stroke admissions were recruited. Progressing stroke was defined by deterioration in components of the Scandinavian Stroke Scale. Hemostatic markers (coagulation factors VIIc, VIIIc, and IXc, prothrombin fragments 1+2 [F1+2], thrombin-antithrombin complexes [TAT], D-dimer, fibrinogen, von Willebrand factor [vWF] and tissue plasminogen activator) were measured within 24 hours of symptom recognition.

RESULTS

Fifty-four (25%) of the 219 patients met criteria for progressing stroke. F1+2 (median 1.28 versus 1.06 nmol/L, P=0.01), TAT (5.28 versus 4.07 microg/L, P<0.01), D-dimer (443 versus 194 ng/mL, P<0.001) and vWF (216 versus 198 IU/dL, P<0.05) levels were higher in these patients than in stable/improving patients. In logistic regression analysis, with all important clinical and laboratory variables included, only natural log D-dimer (odds ratio [OR]: 1.87; 95% confidence interval [CI]: 1.38 to 2.54; P=0.0001) and mean arterial blood pressure (OR: 1.26 per 10 mm Hg change; 95% CI: 1.05 to 1.51; P=0.01) remained independent predictors of progressing stroke.

CONCLUSIONS

There is evidence of excess thrombin generation and fibrin turnover in patients with progressing ischemic stroke. Measurement of D-dimer levels can identify patients at high risk for stroke progression. Further research is required to determine whether such patients benefit from acute interventions aimed at modifying hemostatic function.

Cross-linked fibrin degradation products (D-dimer), plasma cytokines, and cognitive decline in community-dwelling elderly persons

OBJECTIVES

To investigate the effect of coagulation and inflammatory pathway activation on future cognitive decline in older persons.

DESIGN

Prospective cohort study.

SETTING

Rural and urban communities in North Carolina.

PARTICIPANTS

Community-dwelling older people enrolled in the Duke Established Populations for Epidemiologic Studies of the Elderly in 1986.

MEASUREMENTS

In 1992, blood was drawn for assay of D-dimer (1,723 subjects), Interleukin-6 (1,726 subjects), and other cytokines (1,551 subjects). Cognitive and functional assessments were performed in 1986, 1989, 1992, and 1996. Cognition was measured using the Short Portable Mental Status Questionnaire.

RESULTS

Cognitive decline over a 4-year period was significantly correlated (P<.001) with D-dimer, age, race, and physical performance status as measured using the Rosow-Breslau and Nagi instruments. After controlling for demographics, functional status, and comorbidities, D-dimer remained predictive of cognitive decline. Proinflammatory cytokines were not associated with current cognitive status in cross-sectional analyses or with incident cognitive decline in prospective analyses.

CONCLUSION

In a large sample of community-dwelling elders, higher levels of D-dimer were predictive of cognitive decline over a 4-year period. No clinically significant associations were found between age-related peripheral cytokine dysregulation and cognition.

Inflammation and infections as risk factors for ischemic stroke

BACKGROUND

Inflammatory processes have fundamental roles in stroke in both the etiology of ischemic cerebrovascular disease and the pathophysiology of cerebral ischemia. We summarize clinical data on infection and inflammation as risk or trigger factors for human stroke and investigate current evidence for the hypothesis of a functional interrelation between traditional risk factors, genetic predisposition, and infection/inflammation in stroke pathogenesis.

SUMMARY OF REVIEW

Several traditional vascular risk factors are associated with proinflammatory alterations, including leukocyte activation, and predispose cerebral vasculature to thrombogenesis on inflammatory stimulation. Furthermore, accumulation of inflammatory cells, mainly monocytes/macrophages, within the vascular wall starts early during atherogenesis. During later disease stages, their activation can lead to plaque rupture and thrombus formation, increasing stroke risk. Inflammatory markers (eg, leukocytes, fibrinogen, C-reactive protein) are independent predictors of ischemic stroke. Chronic infections (eg, infection with Chlamydia pneumoniae or Helicobacter pylori) were found to increase the risk of stroke; however, study results are at variance, residual confounding is not excluded, and causality is not established at present. In case-control studies, acute infection within the preceding week was a trigger factor for ischemic stroke. Acute and exacerbating chronic infection may act by activating coagulation and chronic infections and may contribute to atherogenesis. Genetic predisposition of the inflammatory host response may be an important codeterminant for atherogenesis and stroke risk.

CONCLUSIONS

Inflammation contributes to stroke risk via various interrelated mechanisms. Infectious diseases, traditional risk factors, and genetic susceptibility may cooperate in stimulating inflammatory pathways. Final proof of a causal role of infectious/inflammatory mechanisms in stroke pathogenesis is still lacking and will require interventional studies.

Platelet serotonin transporter in stroke patients

OBJECTIVES

Post-stroke depression can be treated with serotonin transport inhibitors suggesting a role for the serotonin system in these patients. The number of platelet serotonin transporters in stroke patients and in control subjects have been measured in this study.

MATERIAL AND METHODS

Newly admitted stroke patients who did develop or who did not develop a post-stroke depression, non-acute patients who previously had had a stroke and control subjects were compared. The number of platelet serotonin transporters was analysed by ligand binding methodology.

RESULTS

The number of platelet serotonin transporters was low shortly after a stroke compared with normal subjects; no difference was found between the stroke patients who developed a post-stroke depression and those who did not.

CONCLUSION

A low number of platelet serotonin transporters may be a non-specific state marker for a condition as acute stroke.

Association between inflammation and hemostatic markers in atherothrombotic stroke

INTRODUCTION

It has been reported that the influence of fibrinogen on the incidence of ischemic events is related to inflammation processes and reflects an association with advance atherosclerosis. The aim of this study was to evaluate the association of thrombogenic and inflammatory profiles in patients who have suffered a stroke.

MATERIALS AND METHODS

The study involved 17 patients with atherothrombotic stroke and 34 healthy subjects as control group. The patients were examined 48 h, 3 and 6 months after the stroke occurred. To determine the inflammatory and thrombogenic profiles, plasma levels of fibrinogen, total sialic acid (TSA), C-reactive protein (CRP), tissue factor (TF) and fibrin D-dimer (D-dimer) were measured.

RESULTS

The study showed that at 48 h and 3 months the levels of fibrinogen, TF, D-dimer, TSA and CRP were significantly higher than control group. TF, D-dimer and TSA remains significantly elevated throughout the entire study period. TF and D-dimer decreased over time without reaching the normal values. The multiple regression analysis showed that, at 48 h, 68% of the variance of fibrinogen and 22% of the variance of TF could be explained by the influence of CRP. At 3 and 6 months, 78% of the variance of fibrinogen could be explained by the influence of TSA.

CONCLUSIONS

The results suggest a relation among inflammation markers, fibrinogen and TF in the acute phase of stroke. As TF and D-dimer are still elevated at 6 months, an increased thrombogenicity for a longer period following the acute event is present.

Changes in platelet P-selectin and in plasma C-reactive protein in acute atherosclerotic ischemic stroke treated with a loading dose of clopidogrel

BACKGROUND

The surface expression of P-selectin on platelets contributes to the progression of inflammatory processes and thrombosis in atherothrombosis. In this study, we showed that the combination regimen of clopidogrel with aspirin could downregulate the P-selectin expression on platelets and the plasma concentration of C-reactive protein (CRP) in acute stage of atherosclerotic ischemic stroke.

METHODS

Patients with acute ischemic stroke (<24 hours) were randomized for 7 days to combined regimen of clopidogrel and aspirin (n = 24) or intravenous heparin with aspirin (n = 28). We measured the changes of National Institute of Health Stroke Scale (NIHSS) scores, CRP concentration, and surface expressions of P-selectin on platelets during 7 days.

RESULTS

The combined regimen of clopidogrel and aspirin significantly reduced platelet P-selectin expression (93.6 +/- 16.6, p < 0.01) and plasma concentration of CRP (1.2 +/- 1.5 mg/dl, p < 0.01) after 7 days of stroke onset compared with the values (P-selectin; 115.5 +/- 20.7, CRP; 2.5 +/- 2.8 mg/dl) of initial 24 hr. Also, the clinical improvement, as measured by NIHSS score, was significant in the clopidogrel loading group at 7 days (6.2 +/- 5.5, p < 0.05) compared to the initial 24 hrs (10.1 +/- 7.6).

CONCLUSION

Our results indicate that the combined regimen of clopidogrel and aspirin has beneficial effects on regulating platelet activation and inflammatory processes in acute atherosclerotic ischemic stroke. Thus, this combination regimen deserves further evaluation in clinical trial for the treatment of acute atherosclerotic ischemic stroke.

Inflammation, hemostatic markers, and antithrombotic agents in relation to long-term risk of new cardiovascular events in first-ever ischemic stroke patients

BACKGROUND AND PURPOSE

The measurement of markers of inflammation or thrombosis has been proposed as a method to improve the prediction of risk in patients with vascular disease. We evaluated the usefulness of these markers as predictors of cardiovascular events in ischemic stroke patients.

METHODS

We analyzed levels of C-reactive protein (CRP), fibrinogen, and D-dimer within the first 24 hours after stroke onset in 473 first-ever ischemic stroke patients and determined the cumulative survival curves free of cardiovascular events in relation to the level of each of these markers according to the Kaplan-Meier method. We adjusted for possible confounding variables using a multivariate Cox proportional-hazards model.

RESULTS

Patients in the highest tertiles of D-dimer, fibrinogen, and CRP were associated with an excess risk of new cardiovascular events of 36% (P=0.0134), 63% (P<0.0001), and 72% (P<0.0001), respectively, compared with patients in the lowest tertile. The patients in the highest tertile of CRP had 4 times the risk (hazard ratio, 4.04; P<0.0001) of a new cardiovascular event. Smoking, age, sex, and body mass index did not modify risk, and risk was independent of other confounding variables and of D-dimer and fibrinogen levels. The use of ticlopidine was associated with a significant risk reduction among patients with lower (86%, P=0.0159) and middle (69%, P<0.0001) levels of CRP, whereas a nonsignificant excess risk (27%, P=0.3896) was evident among those with the highest levels.

CONCLUSIONS

Elevated levels of CRP, more than of D-dimer and fibrinogen, are related to the risk of new cardiovascular events after ischemic stroke. The efficacy of antiplatelet therapy in secondary prevention appears to be directly related to level of inflammatory and thrombotic markers.

C-reactive protein is elevated in symptomatic compared with asymptomatic patients with carotid artery disease

OBJECTIVES

to investigate the level of inflammatory markers between symptomatic and asymptomatic carotid stenosis patients.

DESIGN

cross-sectional study.

MATERIALS AND METHODS

a prospective study of 137 consecutive patients, admitted electively for carotid endarterectomy during 1997-2000, was conducted. 125 patients had cerebrovascular symptoms: either stroke (neurological deficit >24 h), Transient ischaemic attack (neurological deficit<24 h) or amaurosis fugax. Twelve patients were asymptomatic. A medical history and a fasting venous blood sample were taken from each patient around 6 weeks before surgery. The plasma concentrations of cholesterol and of inflammatory markers; (high sensitivity C-reactive protein (hs-CRP), sICAM-1, sVCAM-1, sE-selectin) were determined.

RESULTS

the concentration of hs-CRP in the symptomatic group (3.9 mg/L) was significantly higher than in the asymptomatic group (2.1 mg/L; p = 0.04). These concentrations were within normal range (<10 mg/L). sICAM-1, sVCAM-1, sE-selectin and total cholesterol concentrations were not different between the two groups.

CONCLUSION

plasma hs-CRP was elevated in symptomatic compared to asymptomatic patients with carotid artery disease. High sensitivity C-reactive protein has been shown to be of prognostic value in a number of cardiovascular conditions and this study suggests it may be of value to identify patient at high risk of developing neurological deficits.