Elevated levels of D-dimers increase the risk of ischaemic and haemorrhagic stroke

D-dimer - a multifaceted molecule

D-dimer, a universally unique marker for fibrin degradation, is generated through the enzymatic interplay of thrombin, factor XIIIa, and plasmin. The emergence of D-dimer-containing fibrin molecules occurs in both intravascular and extravascular spaces during pivotal physiological processes like haemostasis, thrombosis, and tissue repair. Given the inherently physiological nature of fibrin formation and fibrinolysis, basal levels of D-dimer fragments are present in plasma. Beyond its role as a marker of routine physiological processes, aberrations in D-dimer levels are indicative of a spectrum of conditions, both non-pathological and pathological. The clinical utility of D-dimer has been firmly established, particularly in scenarios like venous thromboembolism (VTE), pulmonary embolism (PE), deep vein thrombosis (DVT), and disseminated intravascular coagulation (DIC). Additionally, recent applications have extended to assess the prognosis of COVID-19. While D-dimer is commonly associated with thrombotic conditions, its elevation is not confined to these conditions alone. Elevated D-dimer levels are observed across various diseases, where its significance extends beyond diagnostic indicators to prognostic implications.

Correlation and risk factors of peripheral and cervicocephalic arterial atherosclerosis in patients with ischemic cerebrovascular disease

Patients with ischemic cerebrovascular disease (ICVD) frequently develop concomitant peripheral artery disease (PAD) or renal artery stenosis (RAS), and multiterritorial atherosclerotic patients usually have a worse prognosis. We aimed to evaluate the status of peripheral atherosclerosis (AS) and cervicocephalic AS (CAS) in ICVD patients with AS, their correlation, and related risk factors contributing to coexisting cervicocephalic-peripheral AS (CPAS). Based on the severity and extent of AS evaluated by computed tomography angiography and ultrasound, the degree of AS was triple categorized to assess the correlation between CAS and PAD/RAS. CAS and PAD/RAS were defined as the most severe stenosis being ≥ 50% luminal diameter in cervicocephalic or lower limb arteries, and a peak systolic velocity at the turbulent site being ≥ 180 cm/s in the renal artery. Among 403 patients with symptom onset within 30 days, CAS, PAD, and RAS occurrence rates were 68.7%, 25.3%, and 9.9%, respectively. PAD was independently associated with the degree of extracranial and intracranial CAS (p = 0.042, OR = 1.428, 95% CI 1.014-2.012; p = 0.002, OR = 1.680, 95% CI 1.206-2.339), while RAS was independently associated with the degree of extracranial CAS (p = 0.001, OR = 2.880, 95% CI 1.556-5.329). Independent CPAS risk factors included an ischemic stroke history (p = 0.033), increased age (p < 0.01), as well as elevated fibrinogen (p = 0.021) and D-dimer levels (p = 0.019). In conclusion, the occurrence rates of RAS and PAD in ICVD patients with AS is relatively high, and with the severity of RAS or PAD increase, the severity of CAS also increase. Strengthening the evaluation of peripheral AS and controlling elevated fibrinogen might be crucial for preventing and delaying the progression of multiterritorial AS in ICVD patients with AS, thereby improving risk stratification and promoting more effective prevention and treatment strategies.

Systematic review and meta-analysis of studies comparing baseline D-dimer level in stroke patients with or without cancer: Strength of current evidence

Objectives

D-dimer levels are increased in stroke and cancer. Cancer patients are at a higher risk of stroke. However, the evidence is unclear if high D-dimer in stroke patients can suggest the diagnosis of concomitant cancer or the development of stroke in a cancer patient. The objective is to assess the evidence available on the baseline D-dimer level in stroke patients with and without cancer.

Materials and Methods

We conducted the systematic review and meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. We searched PUBMED, Cochrane, ScienceDirect, and Scopus for potentially eligible articles published till June 2023. All the review steps were iterative and done independently by two reviewers. The Newcastle-Ottawa scale tool was used to assess the quality of included studies for case control and cohort studies and the Agency for Healthcare Research and Quality tool for cross-sectional studies. The qualitative synthesis is presented narratively, and quantitative synthesis is shown in the forest plot using the random effects model. I2 of more than 60% was considered as high heterogeneity.

Results

The searches from all the databases yielded 495 articles. After the study selection process, six papers were found eligible for inclusion in the qualitative and quantitative synthesis. In the present systematic review, 2651 patients with ischemic infarcts are included of which 404 (13.97%) patients had active cancer while 2247 (86.02%) did not. The studies included were of high quality and low risk of bias. There were significantly higher baseline D-dimer levels in stroke patients with cancer than in non-cancer patients with a mean difference of 4.84 (3.07-6.60) P < 0.00001.

Conclusion

D-dimer is a simple and relatively non-expensive biomarker that is increased to significant levels in stroke patients, who have cancer and therefore may be a tool to predict through screening for active or occult cancer in stroke patients.

The use of D-dimer in the diagnosis and risk assessment of intracardiac thrombus among patients with dilated cardiomyopathy

D-dimer is a biomarker of coagulation and fibrinolytic system activation in response to the body's hypercoagulable state. The study aims to investigate the usefulness of D-dimer in diagnosing and assessing the risk of intracardiac thrombus in patients with dilated cardiomyopathy (DCM). Consecutively enrolled in this study were patients with DCM who were admitted to our center for the first time. The diagnostic value was evaluated using the receiver operating characteristic (ROC) curve. Additionally, we used univariate and multivariate logistic regression to investigate the association between D-dimer and intracardiac thrombus. We also performed smooth curve fitting, threshold saturation effect analysis, and subgroup analysis. In total, 534 patients were enrolled in the study, and among them, 65 patients had intracardiac thrombus. Mural thrombus was the predominant type of thrombus, which was mainly located in the left ventricular apex. The optimal cut-off value of D-dimer for the diagnosis of intracardiac thrombus was 484 ng/mL, with a sensitivity and specificity of 0.769 and 0.646, respectively. In both unadjusted and adjusted logistic regression models, a positive association was found between D-dimer and intracardiac thrombus. Curve fitting and threshold effect analysis revealed two inflection points in the relationship between D-dimer and intracardiac thrombus (non-linear test: P = 0.032). When D-dimer was equal to 362 ng/mL, the odds ratio (OR) was 1, and the risk of thrombus gradually increased until it reached 4096 ng/mL, after which the trend no longer increased. Within this range, a twofold increase in D-dimer was associated with a 103.2% increased risk (OR = 2.032; 95% CI 1.293-3.193; P < 0.01). In the subgroup analysis, there was a significant interaction between D-dimer and BMI on intracardiac thrombus (P value for interaction was 0.013), and the risk was higher in patients with a BMI ≥ 25 kg/m2 (OR = 3.44; 95% CI 1.86-6.36; P < 0.01).

Comparison of circulating lipid profiles, D-dimer and fibrinogen levels between hypertensive patients with and without stroke

BACKGROUND

Stroke is one of the leading causes of global mortality and disability, particularly in hypertensive patients. This study aimed to compare lipid profile, fibrinogen, and D-dimer levels between hypertensive patient with and without stroke.

METHODS

This was a facility-based cross-sectional study conducted from November 2022 to January 2023 among 115 hypertensive patients (70 patients without stroke and 45 with stroke) who had follow-up at Yikatit 12 Hospital Medical College, Ethiopia. All data analyses were done using SPSS version 25.0 and comparisons of variables between groups were made using the Chi-square test, independent sample t-test, and Mann-Whitney U test. Multiple logistic regression analysis was done to identify predictors of stroke among hypertensive patients. A p-value <0.05 was assumed to be statistically significant for all statistical tests.

RESULTS

Significantly elevated levels of TC, LDL-C, D-DI, and fibrinogen were observed in the stroke group than in the non-stroke group (p-value<0.05). The mean values of TC, D-DI, and fibrinogen were significantly higher in patients with ischemic stroke compared to those with hemorrhagic stroke. Duration of hypertension (AOR: 1.21; CI: 1.10, 2.09), TC (AOR:1.07; CI: 1.01, 1.22), D-DI (AOR: 1.15; CI: 1.05, 1.69) and fibrinogen (AOR:1.19; CI: 1.10, 2.89) were identified to be independent predictors of stroke in hypertensive patients.

CONCLUSION

The circulating levels of TC, LDL-C, D-DI and fibrinogen in hypertensive patients with stroke were significantly higher than in those without stroke. But only TC, D-DI, and fibrinogen were found to be predictors of stroke in hypertensives. Considerably higher TC, D-DI, and fibrinogen levels were also seen in patients with ischemic stroke than in those with hemorrhagic stroke. This confirms the key roles of dyslipidemia (hypercholesterolemia) and aberrant hemostatic activation to stroke development, notably ischemic stroke.

Association between D-dimer and long-term mortality in patients with acute severe hypertension visiting the emergency department

OBJECTIVE

High levels of D-dimer, a marker of thrombotic events, are associated with poor outcomes in patients with various cardiovascular diseases. However, there has been no research on its prognostic implications in acute severe hypertension. This study investigated the association between D-dimer levels and long-term mortality in patients with severe acute hypertension who visited the emergency department.

DESIGN AND METHOD

This observational study included patients with acute severe hypertension who visited the emergency department between 2016 and 2019. Acute severe hypertension was defined as a systolic blood pressure ≥ 180 mmHg or a diastolic blood pressure ≥ 100 mmHg. Among the 10,219 patients, 4,127 who underwent D-dimer assay were analyzed. The patients were categorized into tertiles based on their D-dimer levels at the time of emergency department admission.

RESULTS

Among the 4,127 patients with acute severe hypertension, 3.1% in the first (lowest) tertile, 17.0% in the second tertile, and 43.2% in the third (highest) tertile died within 3 years. After the adjustment for confounding variables, the third tertile of the D-dimer group (hazard ratio, 6.440; 95% confidence interval, 4.628-8.961) and the second tertile of the D-dimer group (hazard ratio, 2.847; 95% confidence interval, 2.037-3.978) had a significantly higher risk of all-cause mortality over 3 years than the first tertile of the D-dimer group.

CONCLUSIONS

D-dimer may be a useful marker for identifying the risk of mortality among patients with acute severe hypertension who visit the emergency department.

A Nomogram Based on CT Radiomics and Clinical Risk Factors for Prediction of Prognosis of Hypertensive Intracerebral Hemorrhage

Purpose. To develop and validate a clinical-radiomics nomogram based on clinical risk factors and CT radiomics feature to predict hypertensive intracerebral hemorrhage (HICH) prognosis. Methods. A total of 195 patients with HICH treated in our hospital from January 2018 to January 2022 were retrospectively enrolled and randomly divided into two cohorts for training (n = 138) and validation (n = 57) according to the ratio of 7 : 3. All CT radiomics features were extracted from intrahematomal, perihematomal, and combined intra- and perihematomal regions by using free open-source software called 3D slicer. The least absolute shrinkage and selection operator method was used to select the optimal radiomics features, and the radiomics score (Rad-score) was calculated. The relationship between Rad-score, clinical risk factors, and the HICH prognosis was analyzed by univariate and multivariate logistic regression analyses, and the clinical-radiomics nomogram was built. The area under the receiver operating characteristic curve (AUC) and decision curve analysis (DCA) were used to evaluate the performance of the clinical-radiomics nomogram in predicting the prognosis of HICH. Results. A total of 1702 radiomics features were extracted from the CT images of each patient for analysis. By univariate and stepwise multivariate logistic regression analyses, age, sex, RBC, serum glucose, D-dimer level, hematoma volume, and midline shift were clinical risk factors for the prognosis of HICH. Rad-score and clinical risk factors developed the clinical-radiomics nomogram. The nomogram showed the highest predictive efficiency in the training cohort (AUC = 0.95, 95% confidence interval (CI), 0.92 to 0.98) and the validation cohort (AUC = 0.90, 95% CI, 0.82 to 0.98). The calibration curve indicated that the clinical-radiomics nomogram had good calibration. DCA showed that the nomogram had high applicability in clinical practice. Conclusions. The clinical-radiomics nomogram incorporated with the radiomics features and clinical risk factors has good potential in predicting the prognosis of HICH.

Association between D-dimer levels and long-term mortality in patients with aneurysmal subarachnoid hemorrhage

OBJECTIVE

D-dimer is a marker for hypercoagulability and thrombotic events. The authors sought to investigate whether D-dimer levels predicted long-term mortality in patients with aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

This was a retrospective study of patients with aSAH in West China Hospital, Sichuan University, between December 2013 and June 2019. D-dimer levels were measured within 24 hours after admission and were grouped by quartiles. The primary outcome was long-term mortality. Patient deaths were determined through the Household Registration Administration System in China, with a median of 4.4 years of follow-up.

RESULTS

This study included 2056 patients. Compared with patients with the lowest quartile (0.00-0.97 mg/L) of D-dimer levels, the odds of long-term mortality were significantly higher in all other patients, including those with D-dimer levels between 0.97 mg/L and 1.94 mg/L (adjusted hazard ratio [aHR] 1.85, 95% CI 1.32-2.60), those with D-dimer levels between 1.94 mg/L and 4.18 mg/L (aHR 1.94, 95% CI 1.40-2.70), and those patients with the highest quartile (> 4.18 mg/L) of D-dimer levels (aHR 2.35, 95% CI 1.70-3.24; p < 0.001). Similar results were observed for the endpoints of 1-year mortality and long-term mortality in 1-year survivors.

CONCLUSIONS

Elevated D-dimer levels at admission were associated with short-term and long-term mortality. This biomarker could be considered in future risk nomograms for long-term outcomes and might support future management decisions.

The correlation of D-dimer to stroke diagnosis within 24 hours: A meta-analysis

Background

Diagnosing D‐Dimer early is essential to optimize clinical treatment and quality of life and reduce mortality. This study aims to identify the difference of D‐Dimer levels (ng/ml) in patients with stroke within the 6‐ and 24‐h period compared to patients that mimic stroke.

Methods

An electronic database search across PubMed/MEDLINE, Cochrane, Web of Science, CINAHL, EMBASE, and Scopus was conducted until December 10, 2021. Studies were eligible if they included adult patients with stroke compared to stroke mimics or controls reporting D‐Dimer values. Quality assessment was conducted using GRADE. The standardized mean difference and 95% confidence intervals were calculated in addition to the difference of means in the crude form. Heterogeneity was assessed using Cochran's Q statistic and the I² index. A random‐effects model was used. The statistical analysis was conducted using RevMan 5.4.

Results

Out of 2901, there were 318 (11%) participants from upper‐middle‐income countries, whereas the others were from high‐income countries. Large positive effect size was found for D‐Dimer in the stroke group (Cohen's d = 2.82 [1.73–3.9]; p < 0.00001), meaning that those with stroke had higher D‐Dimer values on presentation compared to the stroke mimics/controls. A large difference in means was found in the two groups (MD = 685.1 [324.2, 1045.99]; p < 0.00001), suggesting that there was a significantly higher laboratory value in the stroke group.

Conclusion

Our findings must be used in caution as the most reliable diagnostic tests for stroke are CT and MRI. Laboratory testing such as D‐Dimer values is a valuable clinical adjuvant in diagnosing total stroke.

Emergency department point‑of‑care biomarkers and day 90 functional outcome in spontaneous intracerebral hemorrhage: A single‑center pilot study

Spontaneous intracerebral hemorrhage (sICH) results in high morbidity and mortality rates, thus identifying strategies for timely prognosis and treatment is important. The present study aimed to analyze the relationship between emergency department point-of-care (POC) blood biomarkers and day 90 functional outcome (FO) in patients with acute (<8 h) sICH. On-site POC determinations, including complete blood count, glucose, cardiac troponin I, D-dimer and C-reactive protein, and derived inflammatory indexes were performed for a cohort of 35 patients. The primary endpoint was a favorable day 90 FO (modified Rankin Score ≤3). Secondary endpoints included early neurological worsening (ENW), day 7/discharge neurological impairment, day 90 independence assessment (Barthel Index <60), hematoma enlargement and perihematomal edema (PHE) growth. A favorable three-month FO was reported in 16 (46%) participants. Older age, previous history of ischemic stroke and initial imagistic parameters, including intraventricular hemorrhage, enlarged contralateral ventricle and cerebral atrophy, significantly predicted an unfavorable FO. The admission D-dimer similarly predicted day 90 FO and the independence status, along with ENW and a more severe day 7/discharge neurological status. The D-dimer also correlated with the initial neurological status and PHE. PHE growth correlated with granulocytes, systemic immune-inflammation index and glycemia. The results suggested that a lower admission D-dimer could indicate an improved day 90 FO of patients with sICH, while also anticipating the development of PHE growth and ENW.

Post-Thrombolytic D-Dimer Elevation Predicts Symptomatic Intracranial Hemorrhage and Poor Functional Outcome After Intravenous Thrombolysis in Acute Ischemic Stroke Patients

BACKGROUND

We aimed to investigate the association of post-thrombolytic D-dimer elevation with symptomatic intracranial hemorrhage (sICH) and functional outcome in AIS patients receiving intravenous thrombolysis.

METHODS

We retrospectively reviewed our database for patients with AIS who received intravenous thrombolysis between August 2018 and December 2021. ΔD-dimer was calculated as follow-up D-dimer minus baseline D-dimer. Poor functional outcome was defined as 3 months modified Rankin score (mRS) 3-6. sICH was defined as cerebral hemorrhagic transformation in combination with clinical deterioration of National Institutes of Health Stroke Scale (NIHSS) score ≥4 points at 24 hours. Binary logistic regression analysis was used to investigate the association of post-thrombolytic D-dimer parameters with sICH and poor functional outcome. The receiver operating characteristic (ROC) curve derived optimal cut-off of different D-dimer parameters was determined at the maximal Youden's Index.

RESULTS

A total of 325 patients were finally included. After controlling for clinical variables, follow-up D-dimer level (OR 1.230; 95% CI 1.119 to 1.351; P < 0.001) and ΔD-dimer (OR 1.347; 95% CI 1.165 to 1.559; P < 0.001) were independently associated with poor functional outcome. Additionally, follow-up D-dimer level (OR 1.095; 95% CI 1.009 to 1.188; P = 0.030) was independently related to sICH. The optimal cut-off value of follow-up D-dimer level for predicting sICH was 4185 μg/L (area under the curve 0.760; sensitivity 76.0%; specificity 81.3%); and the optimal cut-off value of follow-up D-dimer level and ΔD-dimer as a predictor for poor functional outcome was projected to be 3838 μg/L and 2190 μg/L, which yielded a sensitivity and a specificity of 62.3%, 84.5% and 73.8%, 85.2%, respectively.

CONCLUSION

Elevated follow-up D-dimer levels are associated with sICH and poor functional outcome in AIS patients following intravenous rt-PA. Moreover, post-thrombolytic D-dimer elevation, measured by ΔD-dimer, was a better predictive biomarker for long-term outcome at 3 months.

Prospective Assessment of Biomarkers of Hypercoagulability for the Identification of Patients With Severe Coronary Artery Disease. The ROADMAP-CAD Study

In patients with stable coronary artery disease (CAD) blood hypercoagulability figures among factors leading to thrombosis. Tissue factor (TF) exposure at ruptured plaque initiates blood coagulation and hypercoagulability is responsible for thrombus formation. Early identification of patients eligible for angiography is a challenging issue for effective prevention of ACS. This pilot study aimed to identify biomarkers of hypercoagulability that can be prospectively used in risk assessment tools for the evaluation of CAD severity. Biomarkers of hypercoagulability could be a used for the evaluation of CAD severity. Platelet-poor plasma from 66 patients who were referred to coronary angiography was assessed for thrombin generation, phospholipid-dependent clotting time (Procoag-PPL^®) and D-Dimers, and evaluated against atherosclerotic burden. Patients with CAD, as compared to controls, showed attenuated thrombin generation lag time: 4.7 (3.8-5.4) min versus 2.5 (2.1-2.9) min; p < 0.0001, shorter Procoag-PPL^® clotting time 55.0(32-66) s versus 62.8 (42-85) s; p = 0.001), and higher D-Dimer levels 0.509 (0.27-2.58) μg/ml versus 0.309 (0.23-0.39) μg/ml; p = 0.038. Multivariate logistic regression model showed excellent discriminatory value in predicting CAD severity. The ROADMAP-CAD study showed that the Procoag-PPL^® clotting time and thrombin Peak are informative for the the burden of the coronary atherosclerotic disease. The clinical relevance of this observation in the development of a new clinic-biological risk assessment model for early diagnosis of severe CAD has to be examined in a prospective study.

Thromboelastography predicts dual antiplatelet therapy-related hemorrhage in patients with acute ischemic stroke

Background

Stratification of the risk of hemorrhage in patients with acute ischemic stroke following dual antiplatelet therapy (DAPT) is challenging. It remains unclear whether thromboelastography (TEG) can be used to predict DAPT-related hemorrhagic events.

Objective

The present study aims to discover predictors for hemorrhage events after DAPT based on parameters such as TEG.

Methods

A total of 859 patients with acute ischemic stroke who received DAPT were recruited consecutively. Demographic, clinical, and neuroimaging characteristics were evaluated at baseline; TEG parameters were obtained 7 days later after DAPT. Hemorrhagic events were monitored about 1 month after the stroke.

Results

Of the patients, 61 (7.1%) had hemorrhagic events. Patients in the hemorrhage group had a lower adenosine diphosphate (ADP)-induced platelet-fibrin clot maximum amplitude and a higher ADP inhibition rate (ADP%) than those in the non-hemorrhage group (p<0.05). ADP% was confirmed as an independent predictor of hemorrhagic events with an optimal cut-off point of 83.3% (area under the curve (AUC) = 0.665, 95% CI 0.573 to 0.767, p<0.01). We constructed a logistic model based on D-dimer, National Institutes of Health Stroke Scale scores, and ADP% to predict hemorrhagic events in patients with acute ischemic stroke during DAPT (AUC=0.720, 95% CI 0.625 to 0.858, p<0.01), with a sensitivity of 72.1% and a specificity of 76.5%.

Conclusions

Monitoring changes of TEG parameters helps to guide personalized DAPT for patients with ischemic stroke. A 30–82.3% range of ADP% is recommended for DAPT treatment.

Relationships Between D-Dimer Levels and Stroke Risk as Well as Adverse Clinical Outcomes After Acute Ischemic Stroke or Transient Ischemic Attack: A Systematic Review and Meta-Analysis

Objective: Abnormal elevation of D-dimer levels is an important indicator of disseminated intravascular clotting. Therefore, we hypothesized that high D-dimer levels were associated with the risk of stroke and adverse clinical outcomes of patients with acute ischemic stroke (AIS) or transient ischemic attack (TIA).

Methods: The present meta-analysis aimed to systematically analyze the associations between D-dimer and the risk of stroke as well as the clinical outcomes of patients with post-stroke or TIA. Meanwhile, dose–response analyses were conducted when there were sufficient data available. Three electronic databases including Pubmed, the Embase database, and the Cochrane Library were searched by two investigators independently. All the pooled results were expressed as risk ratios (RRs).

Results: Finally, 22 prospective cohort studies were included into this meta-analysis. The results suggested that high D-dimer levels were associated with increased risks of total stroke (RR 1.4, 95%CI 1.20–1.63), hemorrhagic stroke (RR 1.25, 95%CI 0.69–2.25), and ischemic Stroke (RR 1.55, 95%CI 1.22–1.98), and the dose-dependent relationship was not found upon dose–response analyses. Besides, the high D-dimer levels on admission were correlated with increased risks of all-cause mortality [RR 1.77, 95% confidence interval (CI) 1.26–2.49], 5-day recurrence (RR 2.28, 95%CI 1.32–3.95), and poor functional outcomes (RR 2.01, 95%CI 1.71–2.36) in patients with AIS or TIA.

Conclusions: On the whole, high D-dimer levels may be associated with the risks of total stroke and ischemic stroke, but not with hemorrhagic stroke. However, dose–response analyses do not reveal distinct evidence for a dose-dependent association of D-dimer levels with the risk of stroke. Besides, high D-dimer levels on admission may predict adverse clinical outcomes, including all-cause mortality, 5-day recurrence, and 90-day poor functional outcomes, of patients with AIS or TIA. More studies are warranted to quantify the effect of D-dimer levels on the risk of stroke or TIA, so as to verify and substantiate this conclusion in the future.

Plasma D-dimer predicts poor outcome and mortality after spontaneous intracerebral hemorrhage

BACKGROUND

The elevation of plasma D-dimer levels may predict a higher risk of thrombosis and play a role in the pathological process of patients after spontaneous intracerebral hemorrhage (ICH). However, its function in predicting the prognosis of ICH has not been verified on large cases.

PATIENTS AND METHODS

Retrospective cohort study of 1,332 consecutive patients with spontaneous ICH at an academic medical center was conducted. Functional outcome at three months after ICH was dichotomized using the modified Rankin Scale (0-2 versus 3-6). D-dimer level in blood was analyzed within 1 hr of admission. An ICH outcome score combining D-dimer level for evaluating poor functional outcome and mortality was tested.

RESULTS

The proportion of patients with poor functional outcome and mortality at three months was significantly higher in patients with elevated D-dimer level (p < .001). Multivariable analysis demonstrated that elevated D-dimer level was an independent predictor of poor functional outcome (odds ratio 1.486, 95% confidence interval 1.086-2.060, p = .014) and mortality (odds ratio 2.015, 95% confidence interval 1.186-3.423, p = .01). An increasing ICH outcome score combining D-dimer level was associated with increased poor functional outcome and mortality.

CONCLUSIONS

Elevated plasma D-dimer level after spontaneous ICH is associated with poor functional outcome and mortality. The study suggests that elevated D-dimer level has a predictive value for outcome and mortality in patients with spontaneous ICH.

Guidance for the Management of Patients with Vascular Disease or Cardiovascular Risk Factors and COVID-19: Position Paper from VAS-European Independent Foundation in Angiology/Vascular Medicine

COVID-19 is also manifested with hypercoagulability, pulmonary intravascular coagulation, microangiopathy, and venous thromboembolism (VTE) or arterial thrombosis. Predisposing risk factors to severe COVID-19 are male sex, underlying cardiovascular disease, or cardiovascular risk factors including noncontrolled diabetes mellitus or arterial hypertension, obesity, and advanced age. The VAS-European Independent Foundation in Angiology/Vascular Medicine draws attention to patients with vascular disease (VD) and presents an integral strategy for the management of patients with VD or cardiovascular risk factors (VD-CVR) and COVID-19. VAS recommends (1) a COVID-19-oriented primary health care network for patients with VD-CVR for identification of patients with VD-CVR in the community and patients' education for disease symptoms, use of eHealth technology, adherence to the antithrombotic and vascular regulating treatments, and (2) close medical follow-up for efficacious control of VD progression and prompt application of physical and social distancing measures in case of new epidemic waves. For patients with VD-CVR who receive home treatment for COVID-19, VAS recommends assessment for (1) disease worsening risk and prioritized hospitalization of those at high risk and (2) VTE risk assessment and thromboprophylaxis with rivaroxaban, betrixaban, or low-molecular-weight heparin (LMWH) for those at high risk. For hospitalized patients with VD-CVR and COVID-19, VAS recommends (1) routine thromboprophylaxis with weight-adjusted intermediate doses of LMWH (unless contraindication); (2) LMWH as the drug of choice over unfractionated heparin or direct oral anticoagulants for the treatment of VTE or hypercoagulability; (3) careful evaluation of the risk for disease worsening and prompt application of targeted antiviral or convalescence treatments; (4) monitoring of D-dimer for optimization of the antithrombotic treatment; and (5) evaluation of the risk of VTE before hospital discharge using the IMPROVE-D-dimer score and prolonged post-discharge thromboprophylaxis with rivaroxaban, betrixaban, or LMWH.

Neurological Manifestations of Severe SARS-CoV-2 Infection: Potential Mechanisms and Implications of Individualized Mechanical Ventilation Settings

In December 2019, an outbreak of illness caused by a novel coronavirus (2019-nCoV, subsequently renamed SARS-CoV-2) was reported in Wuhan, China. Coronavirus disease 2019 (COVID-19) quickly spread worldwide to become a pandemic. Typical manifestations of COVID-19 include fever, dry cough, fatigue, and respiratory distress. In addition, both the central and peripheral nervous system can be affected by SARS-CoV-2 infection. These neurological changes may be caused by viral neurotropism, by a hyperinflammatory and hypercoagulative state, or even by mechanical ventilation-associated impairment. Hypoxia, endothelial cell damage, and the different impacts of different ventilatory strategies may all lead to increased stress and strain, potentially exacerbating the inflammatory response and leading to a complex interaction between the lungs and the brain. To date, no studies have taken into consideration the possible secondary effect of mechanical ventilation on brain recovery and outcomes. The aim of our review is to provide an updated overview of the potential pathogenic mechanisms of neurological manifestations in COVID-19, discuss the physiological issues related to brain-lung interactions, and propose strategies for optimization of respiratory support in critically ill patients with SARS-CoV-2 pneumonia.

D-dimer as a thrombus biomarker for predicting 2-year mortality after percutaneous coronary intervention

Background:

D-dimer has predictive value for mortality in some diseases. This study aimed to evaluate the correlation between D-dimer and mortality in patients undergoing percutaneous coronary intervention (PCI).

Methods:

We examined 10,724 consecutive patients who underwent PCI between January 2013 and December 2013. The primary endpoint was all-cause mortality, and the secondary endpoint was cardiac mortality. Patients were divided according to the median D-dimer level of 0.28 μg/ml. Multivariable model were including age, sex, and risk factors after stepwise selection.

Results:

After a 2-year follow up, 8565 patients with D-dimer data were analyzed. There were 116 (1.35%) all-cause deaths and 64 (0.75%) cardiac deaths. D-dimer levels were significantly higher in the all-cause mortality group [0.42 (0.29, 0.68) μg/ml] and cardiac mortality group [0.48 (0.30, 0.81) μg/ml] than in the survival group [0.28 (0.20, 0.41) μg/ml] (both p < 0.001). Multivariate-adjusted Cox hazard analysis showed that high D-dimer levels (⩾0.28 μg/ml) were significantly associated with all-cause mortality in the total population [hazard ratio (HR): 2.35, 95% confidence interval (CI): 1.44–3.84, p = 0.001], acute coronary syndrome (ACS) subgroup (HR: 1.91, 95% CI: 1.08–3.38, p = 0.027), and stable coronary artery disease (SCAD) subgroup (HR: 3.82, 95% CI: 1.45–10.10, p = 0.007). High D-dimer levels were significantly associated with cardiac mortality in the total population (HR: 3.44, 95% CI: 1.61–7.36, p = 0.001) and the ACS subgroup (HR: 3.33, 95% CI: 1.38–8.03, p = 0.007), but not in the SCAD subgroup (HR: 3.68, 95% CI: 0.80–16.91, p = 0.094).

Conclusions:

D-dimer levels are independently associated with 2-year all-cause mortality and cardiac mortality in patients undergoing PCI.

High level of D-dimer predicts ischemic stroke in patients with infective endocarditis

Background

Ischemic stroke is one of the most prominent and serious neurological complications of infective endocarditis (IE). Our study was designed to evaluate the predictive value of higher level of plasma D‐dimer on admission for the development of ischemic stroke in patients with IE.

Methods

In this prospective study, a total of 173 consecutive patients with IE were recruited from January 2016 to December 2018. Plasma D‐dimer and other clinical indexes of IE patients were measured after admission. The number of patients who developed ischemic stroke during 6‐month follow‐up was recorded, as well as the occurrence time of ischemic stroke.

Results

Ischemic stroke was observed in 38 (22%) patients during 6‐month follow‐up since definite diagnosis of IE. Patients with ischemic stroke had significantly higher levels of plasma D‐dimer than those of patients without stroke (4982 vs 2205 μg/L, P < .001). In addition, Staphylococcus aureus infection (HR: 1.96, 95% CI: 1.51‐2.42), mitral valve vegetation (HR: 1.52, 95% CI: 1.32‐1.75), and higher levels of on‐admission plasma D‐dimer (HR: 1.35, 95% CI: 1.27‐1.43) were significantly associated with ischemic stroke. Moreover, D‐dimer levels ≥3393 μg/L served as a strong predictor for ischemic stroke in patients with IE, and the sensitivity and specificity were 78% and 83%, respectively.

Conclusion

Our study suggested that higher level of D‐dimer on admission was an independent predictor for ischemic stroke in patients with IE. These patients may require special attention, in particular within the first trimester after IE diagnosis.

D-Dimer Is Associated With First-Ever Intracerebral Hemorrhage

Background and Purpose- Hypertension is the most important risk factor for intracerebral hemorrhage (ICH), but further characterization is needed for groups at high risk of ICH. One way to predict the risk of developing a disease is with plasma biomarkers. This study aimed to investigate the association between the biomarker, D-dimer, and ICH risk. Methods- This population-based, nested case-control study was conducted using data from 2 population-based surveys; the Västerbotten Intervention Programme and MONICA Northern Sweden (Monitoring Trends and Determinants in Cardiovascular Disease). All participants underwent a health examination and blood sampling at baseline before the event. Cases (n=141) were diagnosed with a first-ever ICH between 1985 and March 2007. One or 2 controls (n=255) were matched to each case. Results- The median age was 60 years; 39% of participants were women; and the median time from blood sampling to ICH was 5.2 years. When D-dimer was evaluated as a continuous variable, it was significantly associated with ICH. After multivariable adjustment (for hypertension, body mass index, cholesterol levels, diabetes mellitus, and smoking), the odds ratio was 1.36 per SD of D-dimer (95% CI, 1.05-1.77). When participants were stratified in 3 groups according to time from blood sampling at health examination to ICH, we found that the association between D-dimer levels and ICH was most pronounced in individuals with the shortest time from blood sampling to ICH event (<3.5 years; odds ratio, 1.78; 95% CI, 1.05-3.05). Conclusions- High plasma concentrations of D-dimer were associated with increased risk of a future ICH, after adjusting for cardiovascular risk factors. This association was predominantly driven by the cases with the shortest time from blood sampling to ICH event.

Elevated plasma D-dimer levels are associated with short-term poor outcome in patients with acute ischemic stroke: a prospective, observational study

BACKGROUND

Elevated levels of plasma D-dimer increase the risk of ischemic stroke, stroke severity, and the progression of stroke status, but the association between plasma D-dimer level and functional outcome is unclear. The aim of this study is to investigate whether plasma D-dimer level is a determinant of short-term poor functional outcome in patients with acute ischemic stroke (AIS).

METHODS

This prospective study included 877 Chinese patients with AIS admitted to Renmin Hospital of Wuhan University within 72 h of symptom onset. Patients were categorized by plasma D-dimer level: Quartile 1(≤0.24 mg/L), Quartile 2 (0.25-0.56 mg/L), Quartile 3 (0.57-1.78 mg/L), and Quartile 4 (> 1.78 mg/L). The medical record of each patient was reviewed, and demographic, clinical, laboratory and neuroimaging information was abstracted. Functional outcome at 90 days was assessed with the modified Rankin Scale.

RESULTS

Poor outcome was present in 302 (34.4%) of the 877 patients that were included in the study (mean age, 64 years; male, 68.5%). After adjustment for potential confounding variables, higher plasma D-dimer level on admission was associated with poor outcome (adjusted odds ratio 2.257, 95% confidence interval 1.349-3.777 for Q4:Q1; P trend = 0.004). According to receiver operating characteristic (ROC) analysis, the best discriminating factor for poor outcome was a plasma D-dimer level ≥ 0.315 mg/L (area under the ROC curve 0.657; sensitivity 83.8%; specificity 41.4%).

CONCLUSION

Elevated plasma D-dimer levels on admission are significantly associated with poor outcome after admission for AIS, suggesting the potential role of plasma D-dimer level as a predictive marker for short-term poor outcome in patients with AIS.

Plasma D-Dimer Concentrations and Risk of Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis

Background: The aim of our meta-analysis was to evaluate the association between plasma d-dimer and intracerebral hemorrhage (ICH).

Methods: Embase, Pubmed, and Web of Science were searched up to the date of March 19th, 2018, and manual searching was used to extract additional articles. Standard mean difference (SMD) with 95% confidence intervals (CI) was calculated to evaluate d-dimer levels.

Results: Thirteen studies including 891 ICH patients and 1,573 healthy controls were included. Our results revealed that higher levels of d-dimer were displayed in ICH patients than those in healthy controls (95% CI= 0.98–2.00, p< 0.001). Subgroup analysis based on continent of Asia and Europe, sample size, as well as age in relation to d-dimer levels between ICH patients and healthy controls did not change the initial observation; whereas no differences of d-dimer levels were found between ICH and controls in America.

Conclusions: This meta-analysis revealed that high level of d-dimer is associated with the risk of ICH. Plasma d-dimer is suggested to be a potential biomarker for patients with ICH in Asia and Europe rather than in America. There were no impact of sample size-related differences and age-related diversities on the risk of ICH with respect to d-dimer levels.

Coagulation Profile after Spontaneous Intracerebral Hemorrhage: A Cohort Study

BACKGROUND

Intracerebral hemorrhage (ICH) causes death or disability and the incidence increases with age. Knowledge of acute hemostatic function in patients with ICH without anticoagulant and antiplatelet therapy is sparse. Increased knowledge of the coagulation profile in the acute phase of ICH could improve acute treatment and recovery. We investigated coagulation at admission and changes in coagulation during the first 24hours after symptom onset.

METHODS

Enrolled were 41 ICH patients without anticoagulant or antiplatelet therapy admitted to Aarhus University Hospital, Denmark. Blood samples were collected at admission, 6, and 24hours after symptom onset. Thromboelastometry (ROTEM), thrombin generation, and thrombin-antithrombin (TAT) complex were analyzed. Clinical outcome was evaluated using the National Institute of Health Stroke Scale, the Modified Rankin Score, and mortality.

RESULTS

At admission, compared with healthy individuals, ICH patients had increased maximum clot firmness (EXTEM P < .0001; INTEM P < .0001; FIBTEM P < .0001), increased platelet maximum clot elasticity (P < .0001) in ROTEM, higher peak thrombin (P < .0001) and endogenous thrombin potential (P = .01) in thrombin generation, and elevated TAT complex levels. During 24hours after significantly, while thrombin generation showed decreased peak thrombin (P < .0001) and endogenous thrombin potential (P < .0001). Coagulation test results did not differ between patients when stratified according to clinical outcome.

CONCLUSIONS

ICH patients without anticoagulant or antiplatelet therapy demonstrated activated coagulation at admission and within 24hours after symptom onset.

Elevated level of D-dimer increases the risk of stroke

The aim of this study was to systematically evaluate the association between D-dimer level and the risk of stroke through performing a meta-analysis. PubMed, Web of Science, EMBASE and Cochrane Library were searched for potentially eligible literature. Prospective observational studies or case-control studies were included. The study characteristics and relevant data were extracted. Hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were pooled to estimate the association between D-dimer level and the risk of stroke. Seven prospective studies with 22,207 patients and three case-control studies with 2,248 patients were included. For the prospective studies, the pooled HRs of higher D-dimer level for all types of stroke, ischemic stroke and hemorrhagic stroke were 1.55 (95% CI, 1.28- 1.87), 1.62 (95% CI, 1.18-2.22) and 1.30 (95% CI, 0.63-2.68), respectively. The pooled HRs per SD increase in log D-dimer for all types of stroke, ischemic stroke and hemorrhagic stroke were 1.16 (95% CI, 1.06-1.26), 1.11 (95% CI, 1.03-1.21) and 1.11 (95% CI, 0.95-1.30), respectively. For the case-control studies, the pooled OR of higher D-dimer level for acute ischemic stroke was 2.06 (95% CI, 1.08-3.96). No significant publication bias was found in the meta-analysis. In conclusion, our results suggested that higher D-dimer level was associated with higher risk of stroke, especially ischemic stroke.

Haemostasis biomarkers and risk of intracerebral haemorrhage in the REasons for Geographic and Racial Differences in Stroke Study

Pathologic alterations in haemostasis cause bleeding disorders, but it is unknown if variation within the normal range relates to intracerebral haemorrhage (ICH) risk. It was our objective to assess the prospective associations of haemostasis biomarkers with ICH risk. The REasons for Geographic and Racial Differences in Stroke study (REGARDS) recruited 30,239 U. S. individuals aged ≥45 years. ICH was ascertained through biannual telephone contact and review of deaths followed by medical record evaluation. Haemostasis biomarkers (factor VIII (FVIII), factor IX (FIX), factor XI (FXI), fibrinogen, protein C, and D-dimer) were measured in a case cohort study consisting of ICH and a 1,104 person cohort random sample. The hazard ratio (HR) and 95 % confidence interval (CI) by biomarker were estimated using Cox models and adjusted for ICH risk factors. Individuals with a prior history of stroke, ICH or on warfarin were excluded. Over a median 5.8 years 66 ICH occurred. Fibrinogen, FVIII, FXI, and protein C were not associated with ICH risk in any analysis. Lower FIX increased risk of ICH with the bottom versus the top tertile of FIX associated with an HR of 5.68 (95 % CI 2.30, 14.05). D-dimer demonstrated a non-linear relationship with a potential threshold effect with increased risk only in the top 5th percentile (HR 3.22; 95 % CI 1.01, 10.31; pnon-linear = 0.04).In conclusion, low FIX levels within the normal range were associated with increased ICH risk. These data suggest non-pathologic alterations in haemostasis impact intracranial bleeding risk.

Excess long-term mortality in outpatient deep venous thrombosis patients managed in an ambulatory care setting

BACKGROUND

Deep venous thrombosis (DVT) is increasingly being managed in the outpatient setting, particularly patients deemed low-risk at presentation. The long-term outcomes of these patients remain unclear.

AIM

To determine the long-term outcomes of patients with DVT and those with raised D-dimer without DVT managed exclusively by an ambulatory care pathway.

DESIGN

Retrospective cohort analysis.

METHODS

828 consecutive patients assessed at the Ambulatory Care Clinic of a tertiary care university hospital between 1 January and 31 December 2008 for potential lower limb DVT were analysed. Primary and secondary outcome was all-cause mortality and new diagnosis of cancer, respectively. Median follow-up was 6.4 years.

RESULTS

The final cohort comprised 131 patients with DVT, 396 with raised D-dimer without DVT and 165 with normal D-dimer without DVT. Long-term survival was 72.5% for DVT, 75.3% for elevated D-dimer without thrombosis and 93.3% for those with normal D-dimer ( P < 0.0001). The risk of death with DVT remained significant after adjusting for age, gender, previous cancer, recent surgery and previous thromboembolism (HR 2.17, 95% CI [1.07, 4.38]). Cancer accounted for 44.4 and 37.8% of deaths within the first and second groups, respectively. 50% of cancers in the former group were diagnosed during follow-up vs. 95.1% in the latter.

CONCLUSION

The 5-year survival of patients with DVT managed via ambulatory care was worse than expected. An algorithm is urgently needed to identify predictors of adverse outcomes for both these patients as well as those with raised D-dimer without thrombosis.

Effects of clopidogrel therapy on whole blood platelet aggregation, the Plateletworks® assay and coagulation parameters in cats with asymptomatic hypertrophic cardiomyopathy: a pilot study

BACKGROUND

Although scientific evidence is limited, clopidogrel is frequently used as prophylaxis for arterial thromboembolism in cats with hypertrophic cardiomyopathy (HCM).

OBJECTIVES

Evaluating effects of clopidogrel therapy in asymptomatic cats with HCM on (1) conventional whole blood aggregation (WBA), (2) alternative platelet aggregation assessed with tubes of the Plateletworks® assay and (3) standard coagulation parameters.

ANIMALS AND METHODS

Prospective, randomized, double-blind, placebo-controlled pilot study. Fourteen asymptomatic HCM cats were randomly allocated to receive placebo (n = 5) or clopidogrel (18.75 mg/cat q24h, n = 9) as part of a larger study. Aggregation responses (to 20 µM adenosine diphosphate (ADP) and 10 µg/ml collagen) in WBA and the Plateletworks® assay and standard coagulation parameters were evaluated at baseline and after seven days of therapy.

RESULTS

Clopidogrel therapy significantly reduced aggregation responses to ADP and collagen in the Plateletworks® agonists tubes (ADP and collagen: P < 0.001), but did not significantly reduce aggregation responses to ADP and collagen in the WBA technique (ADP: P = 0.07, collagen: P = 0.30). Clopidogrel therapy did not show a significant effect on prothrombin time, activated partial thromboplastin time, antithrombin, D-dimers and fibrinogen concentrations.

CONCLUSION AND CLINICAL IMPORTANCE

Clopidogrel therapy at a dose of 18.75 mg/cat q24h for seven days causes a significant decrease in in vitro platelet aggregation evaluated with the Plateletworks® assay, without affecting standard coagulation parameters in cats with asymptomatic HCM.

Relevance of Interleukin-6 and D-Dimer for Serious Non-AIDS Morbidity and Death among HIV-Positive Adults on Suppressive Antiretroviral Therapy

Background

Despite effective antiretroviral treatment (ART), HIV-positive individuals are at increased risk of serious non-AIDS conditions (cardiovascular, liver and renal disease, and cancers), perhaps due in part to ongoing inflammation and/or coagulation. To estimate the potential risk reduction in serious non-AIDS conditions or death from any cause that might be achieved with treatments that reduce inflammation and/or coagulation, we examined associations of interleukin-6 (IL-6), D-dimer, and high-sensitivity C-reactive protein (hsCRP) levels with serious non-AIDS conditions or death in 3 large cohorts.

Methods

In HIV-positive adults on suppressive ART, associations of IL-6, D-dimer, and hsCRP levels at study entry with serious non-AIDS conditions or death were studied using Cox regression. Hazard ratios (HR) adjusted for age, gender, study, and regression dilution bias (due to within-person biomarker variability) were used to predict risk reductions in serious non-AIDS conditions or death associated with lower “usual” levels of IL-6 and D-dimer.

Results

Over 4.9 years of mean follow-up, 260 of the 3766 participants experienced serious non-AIDS conditions or death. IL-6, D-dimer and hsCRP were each individually associated with risk of serious non-AIDS conditions or death, HR = 1.45 (95% CI: 1.30 to 1.63), 1.28 (95% CI: 1.14 to 1.44), and 1.17 (95% CI: 1.09 to 1.26) per 2x higher biomarker levels, respectively. In joint models, IL-6 and D-dimer were independently associated with serious non-AIDS conditions or death, with consistent results across the 3 cohorts and across serious non-AIDS event types. The association of IL-6 and D-dimer with serious non-AIDS conditions or death was graded and persisted throughout follow-up. For 25% lower “usual” IL-6 and D-dimer levels, the joint biomarker model estimates a 37% reduction (95% CI: 28 to 46%) in the risk of serious non-AIDS conditions or death if the relationship is causal.

Conclusions

Both IL-6 and D-dimer are independently associated with serious non-AIDS conditions or death among HIV-positive adults with suppressed virus. This suggests that treatments that reduce IL-6 and D-dimer levels might substantially decrease morbidity and mortality in patients on suppressive ART. Clinical trials are needed to test this hypothesis.

Plasma d-Dimer and Incident Ischemic Stroke and Coronary Heart Disease: The Atherosclerosis Risk in Communities Study

BACKGROUND AND PURPOSE

Epidemiological studies have documented that plasma d-dimer, a fibrin degradation product, is a risk marker for coronary heart disease, but there is limited prospective evidence for stroke. Given that thrombosis is a key mechanism for many strokes, we studied whether d-dimer is a risk marker for ischemic stroke incidence in the Atherosclerosis Risk in Communities (ARIC) Study.

METHODS

We measured d-dimer in 11 415 ARIC participants free of stroke and coronary heart disease in 1992 to 1995. We followed them for stroke, stroke subtype, and coronary heart disease events through 2012.

RESULTS

Over a median of 18 years of follow-up, 719 participants had incident strokes (628 ischemic and 91 hemorrhagic). d-dimer was associated positively with risk of total, ischemic, and cardioembolic strokes, with risk elevated primarily for the highest quintile of d-dimer. After adjustment for other cardiovascular risk factors, the hazard ratio for the highest versus lowest quintile of d-dimer was 1.30 (95% confidence interval, 1.02-1.67) for total stroke, 1.33 (95% confidence interval, 1.02-1.73) for ischemic stroke, and 1.79 (95% confidence interval, 1.08-2.95) for cardioembolic stroke. There was no association with hemorrhagic, lacunar, or nonlacunar stroke categories. d-dimer was positively but weakly associated with coronary heart disease incidence.

CONCLUSIONS

A higher basal plasma d-dimer concentration in the general population is a risk marker for ischemic stroke, especially cardioembolic stroke.

The current role and future prospects of D-dimer biomarker

D-dimers have been discovered as by-products of fibrinolysis. In situations where the fundamental pathology is associated with increased thrombolytic activity, D-dimer assays could serve an integral role in the clinical workup, and have an already established role in the diagnosis of clinical disorders of venous thromboembolism, and disseminated intravascular coagulation. However, there is growing literature suggesting that this is not the only clinical scenario where D-dimers may be of significance. They may also become an important biomarker in coronary and carotid artery atherosclerosis and aortic diseases. Being a non-invasive and quick means of diagnosis, D-dimers are a cost-effective tool used for diagnosing diseases. With the future being steered in the direction of preventive cardiology, it is imperative for clinicians to understand how to effectively utilize biomarkers in order to diagnose disorders. In this context, we review D-dimer's origin, current clinical utility, and potential future applications.

Circulating Tissue Factor Levels and Risk of Stroke

Background and Purpose—

Tissue factor (TF) expression is increased in inflammatory atherosclerotic plaques and has been related to their thrombogenicity. Blood-borne TF has been also demonstrated to contribute to thrombogenesis. However, few studies have evaluated the association of circulating levels of TF with stroke. We investigated the association of baseline circulating levels of TF with stroke events occurred in the European Prospective Investigation into Cancer and Nutrition-Italy cohort.

Methods—

Using a nested case–cohort design, a center-stratified random sample of 839 subjects (66% women; age range, 35–71 years) was selected as subcohort and compared with 292 strokes in a mean follow-up of 9 years. Blood samples were collected at baseline in citrate, plasma was stored in liquid nitrogen and TF was measured by ELISA (IMUBIND, TF ELISA, Instrumentation Laboratory, Milan, Italy). The odd ratios and 95% confidence intervals, adjusted by relevant confounders (covariates of TF) and stratified by center, were estimated by a Cox regression model using Prentice method.

Results—

Individuals in the highest compared with the lowest quartile of TF plasma levels had significantly increased risk of stroke (odds ratio IVvsI quartile , 2.01; 95% confidence interval, 1.25–3.23). The association was independent from several potential confounders (odds ratio IVvsI quartile , 1.91; 95% confidence interval, 1.15–3.19). No differences were observed between men and women. The increase in risk was restricted to ischemic strokes (odds ratio IVvsI quartile , 2.13; 95% confidence interval, 1.10–4.12; fully adjusted model), whereas high levels of TF were not associated with the risk of hemorrhagic stroke (odds ratio IVvsI quartile , 1.12; 95% confidence interval, 0.49–2.55; fully adjusted model).

Conclusions—

Our data provide evidence that elevated levels of circulating TF are potential risk factors for ischemic strokes.