Relationship between plasma (D)-dimer level and cerebral infarction volume in patients with nonvalvular atrial fibrillation

Construction and validation of a nomogram for predicting 3-month outcome in elderly patients with nonvalvular atrial fibrillation-induced acute ischemic stroke

Aim

Cardiogenic embolism caused by atrial fibrillation (AF) leads to higher disability, mortality, and recurrence rates compared to stroke independent of AF, resulting in a poorer prognosis for patients. Effective risk assessment and timely clinical intervention are essential. This study aimed to develop and validate a personalized nomogram to predict the 3-month outcomes for elderly patients with nonvalvular atrial fibrillation (NVAF) induced acute ischemic stroke (AIS).

Methods

A retrospective cohort study was implemented at Hefei First People's Hospital. Participants were patients diagnosed with NVAF-induced acute ischemic stroke (NVAF-AIS) who fulfilled the study's inclusion criteria. Data collection encompassed baseline demographic, clinical, and laboratory information. The primary endpoint was the 3-month outcome, evaluated using the modified Rankin Scale (mRS). To identify potential predictors, univariate logistic regression and the least absolute shrinkage and selection operator (LASSO) regression algorithm were employed. Subsequently, a binary regression model was established, and internal validation was conducted using bootstrap resampling with 1,000 iterations. The assessment tools included receiver operating characteristic (ROC) curves, calibration curves, and decision curve analysis (DCA). Ultimately, a nomogram was constructed to forecast the 3-month outcomes for this demographic.

Results

A total of 178 patients were included, of whom 95 (53.3%) had a poor outcome (mRS > 2). Independent risk factors for poor outcomes in NVAF-AIS patients included stroke history (OR = 9.140; 95% CI: 3.481-26.923), NIHSS score (OR = 1.167; 95% CI: 1.071-1.284), glycated hemoglobin (HbA1c) (OR = 2.211; 95% CI:1.573-3.220), D-dimer (OR = 1.157; 95% CI: 1.022-1.361), neutrophil-to-lymphocyte ratio (NLR) (OR = 1.531; 95%CI:1.242-1.972), and left atrial diameter (LAD) (OR = 1.163; 95%CI: 1.072-1.280). A nomogram was created based on these factors. The area under the ROC curve (AUC) for the nomogram was 0.933 (95%CI:0.897-0.969) before and 0.933(95%CI:0.895-0.964) after internal validation, demonstrating good discriminative ability. The nomogram also showed excellent calibration and clinical applicability, as confirmed by calibration curve analysis and DCA.

Conclusion

Stroke history, NIHSS score, HbA1c, D-dimer, NLR, and LAD are independent risk factors for poor outcomes in elderly patients with NVAF-AIS. The nomogram, integrating these factors, provides intuitive, individualized predictions for the risk of poor outcomes, aiding in the selection of treatment options for these patients.

The Association between Coagulation and Atrial Fibrillation

The existing literature highlights the presence of numerous coagulation factors and markers. Elevated levels of coagulation factors are associated with both existing and newly diagnosed cases of atrial fibrillation (AF). However, this article summarizes the role of coagulation in the pathogenesis of AF, which includes fibrinogen and fibrin, prothrombin, thrombomodulin, soluble urokinase plasminogen activator receptor, von Willebrand factor, P-selectin, D-dimer, plasminogen activator inhibitor-1, and platelet activation. Coagulation irregularities play a significant role in the pathogenesis of AF.

Prognostic Determinants of Anterior Large Vessel Occlusion in Acute Stroke in Elderly Patients

This study investigated prognostic factors in elderly patients (80 years and older) undergoing mechanical thrombectomy (MT) for anterior circulation large vessel occlusion (LVO) in acute stroke treatment. Of 59 cases, 47.5% achieved a favorable outcome (mRS ≤ 3) at three months, with a mortality rate of 20.3%. Factors associated with better outcomes included younger age, lower admission National Institute of Health Stroke Scale (NIHSS) scores, lower N-terminal pro-brain natriuretic peptide (NT-proBNP) and D-dimer levels, the presence of the first pass effect (FPE), and successful recanalization. However, logistic regression showed that only lower admission NIHSS scores were significantly correlated with favorable outcomes. In addition, this study suggests that lower admission NT-proBNP and D-dimer levels could potentially serve as prognostic indicators for elderly LVO patients undergoing MT.

Preprocedural D-Dimer Level as a Predictor of First-Pass Recanalization and Functional Outcome in Endovascular Treatment of Acute Ischemic Stroke

We aimed to evaluate the association between preprocedural D-dimer levels and endovascular and clinical outcomes. We retrospectively reviewed patients with acute intracranial large-vessel occlusion who underwent mechanical thrombectomy. Plasma D-dimer levels were measured immediately before the endovascular procedure. Endovascular outcomes included successful recanalization, first-pass recanalization (first-pass effect (FPE) and modified FPE (mFPE)), thrombus fragmentation, and the number of passes of the thrombectomy device. Clinical outcomes were assessed at 3 months using the modified Rankin Scale. A total of 215 patients were included. Preprocedural D-dimer levels were lower in patients with FPE (606.0 ng/mL [interquartile range, 268.0-1062.0]) than in those without (879.0 ng/mL [437.0-2748.0]; p = 0.002). Preprocedural D-dimer level was the only factor affecting FPE (odds ratio, 0.92 [95% confidence interval, 0.85-0.98] per 500 ng/mL; p = 0.022). D-dimer levels did not differ significantly based on successful recanalization and thrombus fragmentation. The number of passes of the thrombectomy device was higher (p = 0.002 for trend) and the puncture-to-recanalization time was longer (p = 0.044 for trend) as the D-dimer levels increased. Patients with favorable outcome had significantly lower D-dimer levels (495.0 ng/mL [290.0-856.0]) than those without (1189.0 ng/mL [526.0-3208.0]; p < 0.001). Preprocedural D-dimer level was an independent factor for favorable outcome (adjusted odds ratio, 0.88 [0.81-0.97] per 500 ng/mL; p = 0.008). In conclusion, higher preprocedural D-dimer levels were significantly associated with poor endovascular and unfavorable functional outcomes.

Clinical features of ischemic stroke in patients with nonvalvular atrial fibrillation combined with intracranial atherosclerotic stenosis

BACKGROUND

Nonvalvular atrial fibrillation (NVAF) and intracranial atherosclerotic stenosis (ICAS) are major causes of ischemic stroke. Relatively few studies have focused on the risk factors and clinical features of ischemic stroke caused by NVAF combined with ICAS.

METHOD

We retrospectively evaluated NVAF and/or ICAS in patients with acute ischemic stroke admitted within 72 h after stroke. All patients with acute ischemic stroke underwent diffusion-weighted magnetic resonance imaging (DWI), magnetic resonance angiography (MRA), computed tomography angiography (CTA), and/or digital subtraction angiography (DSA). NVAF was detected by routine electrocardiogram or 24-h Holter examination, Doppler echocardiography, and contrast echocardiography of the right heart.

RESULTS

Among the 635 enrolled patients, NVAF, ICAS, and NVAF+ICAS were diagnosed in 170 (26.77%), 255 (40.16%), and 210 (33.07%) patients, respectively. Patients in the NVAF+ICAS group were older (p < .001), specifically aged ≥75 years (p < .001). The admission time of the NVAF+ICAS group was shorter (p < .001) than that of the ICAS group. The admission NIHSS score of the NVAF group was higher than that of the NVAF+ICAS group (p < .001). HsCRP, NTpro-BNP, and LEVF levels were significantly different among the three groups (p < .001). NVAF+ICAS ischemic stroke occurred mainly in the right hemisphere (52.4%).

CONCLUSION

NVAF with ICAS ischemic stroke is more likely to occur in older patients. Infarctions occurred mainly in the right cerebral hemisphere. Neurological deficits in NVAF are more severe than those in NVAF combined with ICAS and in simple ICAS ischemic strokes. HsCRP, LEVF, andNTpro-BNP seem to be closely associated with NVAF+ICAS ischemic stroke.

Atrial fibrillation and stroke

INTRODUCTION

Stroke is one of the leading causes of mortality and morbidity globally. Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. It is set to reach epidemic proportions. AF is associated with a five-fold increase in risk of stroke. Strokes caused by AF more often are fatal or result in severe disability. Even though the incidence of stroke has been significantly reduced by oral anticoagulation, AF is thought to account for a significant proportion of cryptogenic strokes where no etiology is identified.

AREAS COVERED

This article reviews the literature related to AF and stroke, pathophysiological insights, diagnosis of AF in stroke patients, and its management (Graphical Abstract).

EXPERT OPINION

The pathophysiology of thrombogenesis that links AF and stroke is not well understood and is an area of active research to identify new therapeutic targets to prevent AF and stroke. As the nature of AF and stroke is multifaceted, an integrated care approach to managing AF and stroke is increasingly essential.

Clinical Application of Thromboelastography in Acute Ischemic Stroke

Acute ischemic stroke (AIS), characterized by high morbidity and mortality, has imposed a considerable burden on society. Despite rapid development in the treatment of AIS, there is still a high risk of recurrence. Furthermore, there is a time delay in waiting for the results of conventional coagulation tests in candidate patients for intravenous thrombolysis therapy. Heterogeneous responses to antiplatelet, intravascular thrombolysis, and endovascular therapies also worsen the situation. Thromboelastography (TEG), as a global and portable detection method for hemostasis, facilitates clinicians in disease monitoring, treatment evaluation, and prognosis prediction in AIS. In this narrative review, we provided a comprehensive summary of the clinical application of TEG in ischemic stroke and gave insights to further studies.

High D-dimer concentration is a significant independent prognostic factor in patients with acute large vessel occlusion undergoing endovascular thrombectomy

OBJECTIVE

This study aimed to investigate prognostic factors that affect modified Rankin Scale (mRS) score at 3 months after onset in acute stroke patients with large vessel occlusion (LVO) undergoing endovascular thrombectomy.

METHODS

We retrospectively examined 87 consecutive patients who underwent endovascular cerebral thrombectomy for acute anterior circulation LVO at Oita University Hospital and Nagatomi Neurosurgery Hospital from January 2014 to December 2020.

RESULTS

Age, National Institutes of Health Stroke Scale (NIHSS) score, and D-dimer concentration on admission were significant univariate prognostic factors related to mRS score 3 months after stroke onset. Multivariate logistic regression analysis showed that D-dimer concentration was the only significant independent prognostic factor. The area under the receiver operating characteristic curve for D-dimer concentration and mRS score at 3 months was 0.715 (95% confidence interval, 0.599 - 0.831); sensitivity and specificity were 60.6% and 80.0%, respectively, using a 1.9 μg/mL cutoff value.

CONCLUSIONS

Prognosis may be worse in patients undergoing acute endovascular cerebral thrombectomy with high D-dimer concentration on admission. Other treatment options should be considered for these patients.

Increased plasma D-dimer levels may be a promising indicator for diabetic peripheral neuropathy in type 2 diabetes

BACKGROUND

Increased plasma D-dimer levels have been reported to be associated with a range of adverse health outcomes. This study aimed to determine whether plasma D-dimer is connected to diabetic peripheral neuropathy (DPN) in patients with type 2 diabetes (T2D).

METHODS

This study was part of a series exploring the potential risks for DPN. All patients were questioned for neurologic symptoms, examined for neurologic signs, and received nerve conduction studies to collect nerve action potential onset latency, amplitude, and nerve conduction velocity (NCV). Composite Z scores of latency, amplitude, and NCV were calculated. DPN was confirmed as both at least a neurologic symptom/sign and an abnormality of nerve conduction studies. Coagulation function indices, such as plasma D-dimer levels, were also synchronously detected.

RESULTS

We finally recruited 393 eligible patients for this study, of whom 24.7% (n = 97) were determined to have DPN. The plasma D-dimer level was found to be closely associated with the composite Z score of latency, amplitude, and NCV after adjusting for other coagulation function indices and clinical covariates (latency: β = 0.134, t = 2.299, p = 0.022; amplitude: β = -0.138, t = -2.286, p = 0.023; NCV: β = -0.139, t = -2.433, p = 0.016). Moreover, the prevalence of DPN in the first, second, third, and fourth quartiles (Q1, Q2, Q3, and Q4) of the D-dimer level was 15.2%, 15.9%, 26.4%, and 42.7%, respectively (p for trend < 0.001). The corresponding adjusted odds ratios and 95% CIs for DPN in D-dimer quartiles were 1, 0.79 (0.21-2.99), 1.75 (0.49-6.26), and 5.17 (1.38-19.42), respectively. Furthermore, the optimal cutoff value of the plasma D-dimer level to discriminate DPN was ≥0.22 mg/L (sensitivity = 67.01%, specificity = 58.78%, and Youden index = 0.26) after analysis by the receiver operating characteristic curve.

CONCLUSIONS

Increased plasma D-dimer levels may be a promising indicator for DPN in patients with T2D.

Difference in left atrial D-dimer level in patients with atrial fibrillation treated with direct oral anticoagulant

Background

Atrial fibrillation (AF) may cause cerebral and systemic embolism. An increased D-dimer level indicates hyperactivation of secondary fibrinolysis, resulting in predilection for thrombosis. To clarify the differential effects of anticoagulation therapy, we compared the D-dimer levels in peripheral and left atrial (LA) blood of atrial fibrillation patients scheduled for ablation.

Methods

We analyzed 141 patients with non-valvular AF (dabigatran, n = 30; apixaban, n = 47; edoxaban, n = 64; mean age: 68 years, male: 60%). Peripheral venous blood and LA blood was collected before pulmonary vein isolation. We examined the laboratory and echocardiographic parameters.

Results

After adjusting for baseline characteristics, D-dimer level in the LA was significantly higher in patients treated with edoxaban than that in those on apixaban (0.77 ± 0.05 vs. 0.60 ± 0.05 μg/mL, P = 0.047), although there were no significant differences in peripheral D-dimer levels. We classified the D-dimer value of the LA into a normal group (< 0.9) and a high value group (≥ 1.0); the peripheral prothrombin fragment F1 + 2 level (odds ratio [OR] 1.012; 95% confidence interval [CI]: 1.003–1.022; P = 0.008) and left ventricular ejection fraction (LVEF) (OR, 0.947; 95% CI, 0.910–0.986; P = 0.008) were potential predictors of high LA D-dimer levels.

Conclusions

In apixaban-treated patients, the D-dimer level in the left atrium was lower than in edoxaban-treated patients on the day of ablation, suggesting that the anticoagulant effect of apixaban on the left atrium is better than that of edoxaban in patients with AF.

D-dimer Level is Correlated with Prognosis, Infarct Size, and NIHSS in Acute Ischemic Stroke Patients. Indian J Crit Care Med 2021;25:193-198. [PMID: 33707899 PMCID: PMC7922437 DOI: 10.5005/jp-journals-10071-23744]

Stroke ranks the fourth leading disease causing adult mortality and disability. D-dimer (D-D) is the ultimate product of plasmin-mediated degradation of fibrin-rich thrombi. D-D is a simple readily accessible biomarker employed within the diagnostic algorithms for the exclusion of venous thromboembolism. The correlation between D-D infarct size in MRI brain, APACHE II score, and the National Institute of Health Stroke Scale (NIHSS) score in critically ill acute stroke patients has not been fully investigated before.

Objective

We aimed to investigate the diagnostic and prognostic value of elevated plasma D-D in critically ill patients admitted with acute cerebrovascular accidents. As far as we know, we are the first to investigate the correlation between plasma D-D levels and the ischemic lesion size in MRI brain and also APACHE II score and NIHSS in critically ill acute ischemic cerebrovascular patients.

Setting and participants

A prospective, observational cohort study inside the Critical Care Medicine Department. Thirty patients with AIS were enrolled additionally to 1 healthy age- and sex-matched controls.

Interventions

We employed particle-enhanced, immunoturbidimetric assay to detect plasma D-D concentrations. D-D levels D0 and D1 were measured upon admission and 24 hours later, respectively. We reviewed the patient' s health records; additionally, demographic, clinical, laboratory, and neuroimaging information was abstracted.

Results

D-D concentrations were significantly higher in acute stroke patients compared to healthy controls. ROC curve analysis showed that elevated D-D level more than 310 ng/mL can predict infarct lesion size >1.5 cm in diffusion-weighted MRI brain with sensitivity and specificity (100 and 83%, respectively) and also admission D-D (D0) at cutoff concentration 350 ng/mL and D1 at cutoff value 370 ng/mL are predictors of complicated course with sensitivity and specificity (100 and 84.6%, respectively). There was no significant difference between D0 and D1 D-D levels (p-value >0.05).

Conclusion

The plasma D-D biomarker can be a simple readily available test reliable predictor of infarct lesion size >1.5 cm in DW-MRI and outcome in union with the common practice instrumental tests.

How to cite this article

Abbas NI, Sayed O, Samir S, Abeed N. D-dimer Level is Correlated with Prognosis, Infarct Size, and NIHSS in Acute Ischemic Stroke Patients. Indian J Crit Care Med 2021;25(2):193-198.

D-dimer level elevation can aid in detection of asymptomatic COVID-19 presenting with acute cerebral infarction

Coronavirus disease 2019 (COVID-19) mainly manifests as a respiratory syndrome, besides causing other complications. Severe COVID-19 may also present with coagulopathy, leading to venous thrombosis and cerebral infarction. Generally, acute stroke is a secondary complication in patients displaying respiratory syndromes. Here, we present a case of acute stroke in an 84-year-old female patient who did not manifest any respiratory symptoms. The patient had no cough or fever before the stroke onset; nevertheless, COVID-19 PCR test was positive. The patient also had markedly elevated serum D-dimer levels. Our findings suggest that coagulopathy can occur even in a patient with asymptomatic COVID-19 infection, and to our knowledge, this is the first report of such a case. We concluded that elevated D-dimer levels can serve as an additional COVID-19 screening tool in stroke patients.

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A COVID-19 patient presented with cerebral infarction and no respiratory symptoms.

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D-dimer level was extremely elevated in this asymptomatic COVID-19 patient.

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Elevation of D-dimer levels are necessary to diagnose suspected occult COVID-19.

Prognostic Hemostasis Biomarkers in Acute Ischemic Stroke

Supplemental Digital Content is available in the text.

Objectives—

The prediction of patients at risk for poor clinical outcome after acute ischemic stroke remains challenging. An imbalance of coagulation factors may play an important role in progression and prognosis of these patients. In this systematic review, we assessed the current literature on hemostasis biomarkers and the association with poor clinical outcome in acute ischemic stroke.

Approach and Results—

A systematic search of Embase, Medline, Cochrane Library, Web of Science, and Google Scholar was performed on studies reporting on hemostasis biomarkers and clinical outcome after acute ischemic stroke. Studies were considered eligible if blood samples were collected within 72 hours after symptom onset. Additionally, clinical outcome should be assessed using a disability score (Barthel Index or modified Rankin scale). Methodological quality of included studies was assessed with an adapted version of the Quality Assessment of Diagnostic Accuracy Studies questionnaire. A total of 80 articles were read full text, and 41 studies were considered eligible for inclusion, reporting on 37 different hemostasis biomarkers. No single biomarker appeared to be effective in predicting poor clinical outcome in acute ischemic stroke patients.

Conclusions—

Based on current literature, no clear recommendations can be provided on which hemostasis biomarkers are a predictor of clinical outcome after acute ischemic stroke. However, some biomarkers show promising results and need to be further investigated and validated in large populations with clear defined study designs.

Generation of a Monoclonal Antibody against D-Dimer Using HTS-Based LiCA

D-dimer is an essential diagnostic index of thrombotic diseases. Since the existing anti-D-dimer antibodies vary in quality and specificity, a search for alternative anti-D-dimer antibodies is required. The present study aimed to screen a novel monoclonal antibody (mAb) against D-dimer using a light-initiated chemiluminescence assay (LiCA). In this work, mice were immunized with antigen prepared from human plasma by enzyme hydrolysis. After screening, a novel mAb, DD 2G11, was obtained. The results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis indicated that DD 2G11 could be used as a standard marker for D-dimer. The isotype of DD 2G11 was IgG1, the K_a value was 0.646 nM-1, and the K_d value was 50 nM, indicating that the binding affinity to D-dimer was very high. Furthermore, no cross-reactivity between DD 2G11 and other fibrinogen degradation products (FgDPs) was found. Finally, the correlation between DD 2G11 and the reference antibody (commercial antibody) was investigated by analyzing 56 clinical samples using a latex-enhanced turbidimetric immunoassay (LTIA). The R² value of the linear regression was 0.94538, indicating that DD 2G11 met clinical requirements. In conclusion, the present study provides a more expeditious protocol to screen mAbs and provides a clinically usable mAb against D-dimer.

The emerging value of serum D-dimer measurement in the work-up and management of ischemic stroke

Background

Elevated D-dimer levels are a marker of both thrombin formation and fibrinolysis. Currently D-dimer measurement is routinely used for ruling out venous thromboembolism and diagnosis/monitoring of disseminated intravascular coagulation. Recent emerging data suggest that D-dimer may become an important biomarker in ischemic stroke as well as in cardiovascular diseases.

Aims

To outline the clinical utility of D-dimer in work-up and management of ischemic stroke.

Summary

D-dimer measurement is most useful in stroke with active cancer as it can confirm etiologic diagnosis, predict recurrent stroke risk, and aid treatment decision in cancer-associated stroke. In cryptogenic stroke, high D-dimer levels can also provide clues for the cause of stroke as occult cancer and undetected cardiac embolic source as occult atrial fibrillation and may be helpful in treatment decision making of secondary stroke prevention. Serial D-dimer measurements should be further studied to monitor antithrombotic therapy effectiveness in both cardiogenic and cryptogenic etiologies.

Conclusion

Accumulating data suggests the utility of D-dimer test in the management of ischemic stroke, although the evidence is still limited. Future studies would clarify the role of D-dimer measurement in ischemic stroke.

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.

Brain Natriuretic Peptide Is a Powerful Predictor of Outcome in Stroke Patients with Atrial Fibrillation

Background

Since stroke patients with nonvalvular atrial fibrillation (NVAF) have poor outcomes in general, the prediction of outcomes following discharge is of utmost concern for these patients. We previously reported that brain natriuretic peptide (BNP) levels were significantly higher in NVAF patients with larger infarcts, higher modified Rankin Scale (mRS) score, and higher CHADS₂ score. In the present study, we evaluated an array of variables, including BNP, in order to determine significant predictors for functional outcome in patients with NVAF after acute ischemic stroke (AIS).

Methods

A total of 615 consecutive patients with AIS within 48 h of symptom onset, admitted to our hospital between April 2010 and October 2015, were retrospectively searched. Among these patients, we enrolled consecutive patients with NVAF. We evaluated the mRS score 3 months after onset of stroke and investigated associations between mRS score and the following clinical and echocardiographic variables. Categorical variables included male sex, current smoking, alcohol intake, hypertension, diabetes mellitus, dyslipidemia, coronary artery disease, peripheral artery disease, use of antiplatelet drugs, anticoagulants, or tissue plasminogen activator (tPA), and infarct size. Continuous variables included age, systolic blood pressure (SBP), diastolic blood pressure, hemoglobin, creatinine, D-dimer, brain natriuretic peptide (BNP), left atrial diameter, left ventricular ejection fraction (EF), and early mitral inflow velocity/diastolic mitral annular velocity (E/e’). We also analyzed the association of prestroke CHADS₂, CHA₂DS₂-VASc, and R₂CHADS₂ scores, and National Institutes of Health Stroke Scale (NIHSS) score on admission with mRS score 3 months after the onset of stroke. Patients were classified into 2 groups according to mRS score: an mRS score ≤2 was defined as good outcome, an mRS score ≥3 was defined as poor outcome. To clarify the correlations between categorical or continuous variables and mRS score, uni- and multivariate logistic regression models using the stepwise variable selection method were applied.

Results

Among 157 patients with NVAF after AIS, 63.7% were male and the mean age was 75.9 years. In univariate regression analysis, poor outcome (mRS score ≥3) was associated with use of tPA, infarct size, age, SBP, BNP, EF, and NIHSS score. In multivariate regression analysis, BNP levels (odds ratio [OR] 6.40; 95% confidence interval [CI] 1.26–32.43; p = 0.0235) and NIHSS score (OR 2.87; 95% CI 1.84–4.47; p < 0.001) were significantly associated with poor outcome (mRS score ≥3) after adjusting for use of tPA, infarct size, age, BNP, EF, and NIHSS score.

Conclusions

Apart from NIHSS score, BNP was a very useful predictor for long-term outcomes of patients with NVAF after AIS.

Prognostic Value of Serum D-Dimer in Noncardioembolic Ischemic Stroke

Background: Although D-dimer levels are significantly associated with cardioembolic infarction, the significance of D-dimer levels in relation to the severity and functional outcomes of other stroke subtypes, such as lacunar and large artery atherosclerosis infarction, remains unclear. The purpose of this study was to evaluate whether elevated initial D-dimer levels are significantly and cross-sectionally associated with poor functional outcomes at each time point during a 9-month follow-up period. We also investigated the significance of D-dimer levels in longitudinal temporal changes of functional outcomes in these patients. Methods: We recruited 146 patients with lacunar infarction and 161 patients with large artery atherosclerosis infarction who were consecutively admitted to our hospital after acute stroke. Serum D-dimer levels were evaluated initially and the modified Rankin scale were measured initially and at 1-, 3-, 6-, and 9-month follow-up visits. Results: Patients with higher D-dimer levels had significantly worse initial functional outcomes, and these worse outcomes were maintained throughout the 9-month follow-up period compared with the low D-dimer group. However, regardless of stroke subtype, D-dimer levels did not influence long-term changes in functional outcomes over the 9-month follow-up period. Conclusion: This study suggests that elevated D-dimer levels can be used as a surrogate marker for poor functional outcomes only during the acute stage. Further evaluation of serum D-dimer levels could provide a helpful predictive marker for stroke prognosis.

Plasma D-dimer Level, the Promising Prognostic Biomarker for the Acute Cerebral Infarction Patients

BACKGROUND

Despite being an important cause of death and functional disability, acute cerebral infarction (ACI) lacks accurate and easy tools to predict the outcome of patients beyond clinical variables such as age and stroke severity.

METHODS

To investigate if plasma D-dimer level can be used as such a prognostic biomarker for ACI, so as to better guide patients' management, we studied the association between plasma D-dimer and the functional recovery of 1173 ACI patients. The patients were divided into 2 groups according to modified Rankin Scale (mRS) scores or National Institutes of Health Stroke Scale (NIHSS) scores evaluated on the 30th day after onset.

RESULTS

We observed that plasma D-dimer level correlated significantly with the prognosis of ACI evaluated based on both mRS scores (389.68 ± 32.06 µg/L for poor prognosis versus 377.70 ± 32.68 µg/L for good prognosis, P < .001) and NIHSS scores (387.01 ± 30.60 µg/L for poor prognosis versus 375.23 ± 30.66  µg/L for good prognosis, P < .01). Logistic analysis confirmed that higher D-dimer level was a risk factor for poor prognosis (mRS: odds ratio [OR], 1.604; 95% confidence interval [CI], 1.360-1.892; P < .001; NIHSS: OR, 1.733; 95% CI, 1.461-2.056; P < .01), after adjusted for age, gender, hypertension, diabetes, smoking, and hyperlipidemia.

CONCLUSION

Our results show that plasma D-dimer level is a promising prognosis biomarker for ACI.

Diagnostic Value of Elevated D-Dimer Level in Venous Thromboembolism in Patients With Acute or Subacute Brain Lesions

Objective

To define the risk factors that influence the occurrence of venous thromboembolism (VTE) in patients with acute or subacute brain lesions and to determine the usefulness of D-dimer levels for VTE screening of these patients.

Methods

Medical data from January 2012 to December 2013 were retrospectively reviewed. Mean D-dimer levels in those with VTE versus those without VTE were compared. Factors associated with VTE were analyzed and the odds ratios (ORs) were calculated. The D-dimer cutoff value for patients with hemiplegia was defined using a receiver operating characteristic (ROC) curve.

Results

Of 117 patients with acute or subacute brain lesions, 65 patients with elevated D-dimer levels (mean, 5.1±5.8 mg/L; positive result >0.55 mg/L) were identified. Logistic regression analysis showed that the risk of VTE was 3.9 times higher in those with urinary tract infections (UTIs) (p=0.0255). The risk of VTE was 4.5 times higher in those who had recently undergone surgery (p=0.0151). Analysis of the ROC showed 3.95 mg/L to be the appropriate D-dimer cutoff value for screening for VTE (area under the curve [AUC], 0.63; 95% confidence interval [CI], 0.5-0.8) in patients with acute or subacute brain lesions. This differs greatly from the conventional D-dimer cutoff value of 0.55 mg/L. D-dimer levels less than 3.95 mg/L in the absence of surgery showed a negative predictive value of 95.8% (95% CI, 78.8-99.8).

Conclusion

Elevated D-dimer levels alone have some value in VTE diagnosis. However, the concomitant presence of UTI or a history of recent surgery significantly increased the risk of VTE in patients with acute or subacute brain lesions. Therefore, a different D-dimer cutoff value should be applied in these cases.

Relevance of transthoracic left atrial appendage wall velocity measurement in addition to left atrial volume for noninvasive and quantitative assessment of left atrial thrombogenesis in patients with atrial fibrillation and normal D-dimer levels

PURPOSE

This study examined the role of left atrial (LA) appendage wall velocity (LAAWV) measurement in addition to LA size for the noninvasive assessment of thrombogenesis in patients with atrial fibrillation (AF) and normal plasma D-dimer levels.

METHODS

In 58 non-valvular AF patients, LAAWV and the LA volume index (LAVI) were determined by transthoracic echocardiography. LA appendage flow velocity and severity of spontaneous echo contrast (SEC) were determined by transesophageal echocardiography.

RESULTS

LAAWV was strongly correlated with LA appendage flow velocity (r = 0.82), and LAVI was weakly correlated with LA appendage flow velocity (r = -0.37). As SEC severity increased, LAAWV decreased (p < 0.001) and LAVI increased (p < 0.001). Among 52 patients with normal D-dimer levels, LAAWV < 10 cm/s had 71 % sensitivity and 94 % specificity for diagnosing severe SEC. Severe SEC was not found in 18/32 large LAVI patients (>34 mL/m(2)), but 17 of the 18 patients (94 %) had LAAWV < 10 cm/s. Severe SEC was found in 3/20 patients with normal LAVI, but all of them showed LAAWV < 10 cm/s.

CONCLUSION

The noninvasive measurement of transthoracic LAAWV in addition to LA volume is clinically relevant for quantitatively assessing thrombogenesis in AF patients with normal D-dimer levels.

Embolic Stroke Diagnosed by Elevated D-Dimer in a Patient With Negative TEE for Cardioembolic Source

We report a case of cerebrovascular accident with thromboembolic stroke etiology in a patient who had atrial flutter and negative transesophageal echocardiography (TEE) results. The increased D-dimer levels (1877 ng/mL) initiated referral for magnetic resonance imaging and magnetic resonance angiography of the brain that showed classic recanalization of an embolic thrombus in the angular branch of the left middle cerebral distribution. The D-dimer level of this patient was normalized after 3 months of anticoagulation therapy. Although TEE is considered the gold standard for evaluation of cardiac source of embolism, exclusion of intracardiac thrombus with TEE alone does not eliminate the risk of thromboembolic events. This case highlights the utility of D-dimer as a potential adjunct in the decision-making process to guide investigation of thromboembolism, determine subsequent therapy, and hence reduce the risk of embolic stroke recurrence.

The role of hs-CRP, D-dimer and fibrinogen in differentiating etiological subtypes of ischemic stroke

The aim of this study was to evaluate the diagnostic value of the serum biochemical markers high-sensitivity C-reactive protein (hs-CRP), D-dimer (DD) and fibrinogen (Fg) in differentiating etiological subtypes of ischemic stroke. This study was a retrospective case-only study, consecutively including patients with acute ischemic stroke. All patients were classified into subtypes using the TOAST classification system. A total of 317 patients were evaluated. Hs-CRP and DD levels were significantly different among the subtypes and were the highest in CE, followed by LAA and SAA; no significant difference between the subtypes was found for Fg. Hs-CRP > 6.96 mg/L was classified as the CE subtype, with a sensitivity of 41% and a specificity of 74%; DD > 791.30 ng/mL was classified as CE, with a sensitivity of 58% and a specificity of 78%. The combination of hs-CRP and DD classification as CE yielded a sensitivity of 65% and a specificity of 91%. DD > 791.30 ng/mL was considered an independent predictive factor of CE. Hs-CRP and DD could be useful for identifying the etiological subtypes of acute ischemic stroke, especially for predicting CE. The diagnostic value of DD was higher than that of hs-CRP.

Monitoring biomarkers of cellular injury and death in acute brain injury

BACKGROUND

Molecular biomarkers have revolutionalized diagnosis and treatment of many diseases, such as troponin use in myocardial infarction. Urgent need for high-fidelity biomarkers in neurocritical care has resulted in numerous studies reporting potential candidate biomarkers.

METHODS

We performed an electronic literature search and systematic review of English language articles on cellular/molecular biomarkers associated with outcome and with disease-specific secondary complications in adult patients with acute ischemic stroke (AIS), intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), traumatic brain injury (TBI), and post-cardiac arrest hypoxic ischemic encephalopathic injuries (HIE).

RESULTS

A total of 135 articles were included. Though a wide variety of potential biomarkers have been identified, only neuron-specific enolase has been validated in large cohorts and shows 100% specificity for poor outcome prediction in HIE patients not treated with therapeutic hypothermia. There are many promising candidate blood and CSF biomarkers in SAH, AIS, ICH, and TBI, but none yet meets criteria for routine clinical use.

CONCLUSION

Current studies vary significantly in patient selection, biosample collection/processing, and biomarker measurement protocols, thereby limiting the generalizability of overall results. Future large prospective studies with standardized treatment, biosample collection, and biomarker measurement and validation protocols are necessary to identify high-fidelity biomarkers in neurocritical care.

Hypercoagulability, D-dimer and atrial fibrillation: an overview of biological and clinical evidence

Atrial fibrillation (AF) is the most common among the severe cardiac arrhythmias and carries a significant risk of mortality and morbidity in the general population. The most important complication is represented by development of one or more thrombi in the left atrium of the dyskinetic heart, and their successive cerebral and peripheral embolization. The pathophysiological basis of the thromboembolic complications in AF entails the presence of a hypercoagulable state, which is mirrored by increased concentrations of a variety of prothrombotic markers. D-dimer is universally considered the gold standard among the various biomarkers that reflect activation of coagulation, fibrinolysis, or both, and several studies have assessed its diagnostic and prognostic role in AF. With a few exceptions and despite a broad heterogeneity in the study designs, published data seem to demonstrate that D-dimer values may be associated with the presence of atrial thrombosis, may be predictive of primary adverse outcomes and death, may be correlated with cerebral infarction volume, and may also be a useful parameter for assessing the degree of hypercoagulability of AF patients after cardioversion. If larger prospective studies confirm these findings, D-dimer assessment may hence become an integral part of the clinical decision-making in patients with AF.

Stroke and Bleeding Risks in Patients with Atrial Fibrillation

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with a substantial risk of stroke and mortality. Strokes in patients with AF are associated with a greater disability and poorer outcomes than strokes in patients in sinus rhythm. Patients with AF are at increased risk of bleeding, especially if they use anticoagulant therapy. Recent research in the field of anticoagulation has led to development of new anticoagulants for stroke prevention in addition to antiplatelet agents and warfarin. This review discusses the role of AF as a risk factor for stroke and evaluates the role of various schemes for predicting the risk of stroke and bleeding in patients with AF.

Plasma D-dimer levels are associated with stroke subtypes and infarction volume in patients with acute ischemic stroke

BACKGROUND

It has been suggested that modestly elevated circulating D-dimer values may be associated with acute ischemic stroke (AIS). Thus, the purpose of this study was to investigate the association between plasma D-dimer level at admission and AIS in Chinese population.

METHODS

In a prospective observational study, plasma D-dimer levels were measured using a particle-enhanced, immunoturbidimetric assay on admission in 240 Chinese patients with AIS. The National Institutes of Health Stroke Scale (NIHSS) score was assessed on admission blinded to D-dimer levels.

RESULTS

Plasma median D-dimer levels were significantly (P = 0.000) higher in AIS patients as compared to healthy controls (0.88; interquartiler range [IQR], 0.28-2.11 mg/L and 0.31; IQR, 0.17-0.74 mg/L). D-dimer levels increased with increasing severity of stroke as defined by the NIHSS score(r = 0.179, p = 0.005) and infarct volume(r = 0.425, p = 0.000). Those positive trends still existed even after correcting for possible confounding factors (P = 0.012, 0.000; respectively). Based on the Receiver operating characteristic (ROC) curve, the optimal cut-off value of plasma D-dimer levels as an indicator for diagnosis of cardioembolic strokes was projected to be 0.91 mg/L, which yielded a sensitivity of 83.7% and a specificity of 81.5%, the area under the curve was 0.862(95% confidence interval [CI], 0.811-0.912).

CONCLUSION

We had shown that plasma D-dimer levels increased with increasing severity of stroke as defined by the NIHSS score and infarct volume. These associations were independent other possible variables. In addition, cardioembolic strokes can be distinguished from other stroke etiologies by measuring plasma D-dimer levels very early (0-48 hours from stroke symptom onset).

Effect of hyperthyroidism on the hypercoagulable state and thromboembolic events in patients with atrial fibrillation

OBJECTIVE

To clarify whether hyperthyroidism (HT) itself confers an additional effect on the hypercoagulable state and the risk of ischemic stroke among patients with hyperthyroid atrial fibrillation (AF).

METHODS

We prospectively evaluated plasma D-dimer levels and thromboembolic events among three groups of patients (hyperthyroid AF, n = 62; nonthyroid AF, n = 107, and HT without AF, n = 100). Plasma D-dimer levels were used to evaluate the hypercoagulable state.

RESULTS

The D-dimer level was significantly higher in patients with hyperthyroid AF than in nonthyroid AF (0.66 ± 0.06 vs. 0.34 ± 0.02 mg/l, p < 0.001) and HT without AF (0.66 ± 0.06 vs. 0.27 ± 0.02 mg/l, p < 0.001). During a 3-year follow-up, patients with hyperthyroid AF had a significantly higher incidence of ischemic stroke compared with patients with nonthyroid AF (hazard ratio, HR: 3.2, 95% confidence interval, CI: 1.01-5.59, p = 0.04). Cox regression analysis revealed that age (HR: 2.5, 95% CI: 1.01-1.21, p = 0.05), CHADS2-VAS score (HR: 5.5, 95% CI: 1.51-7.43, p = 0.01) and anticoagulation (HR: 0.45, 95% CI: 0.07-0.54, p = 0.01) were independent predictors of risk for the occurrence of ischemic stroke.

CONCLUSIONS

The present study suggests that HT may enhance the hypercoagulable state and the risk of ischemic stroke in patients with AF.

Potential serum biomarkers in the pathophysiological processes of stroke

Stroke is a leading cause of death and serious long-term disability. Ischemic stroke is the major subtype of stroke. Currently, its diagnosis is mainly dependent upon clinical symptoms and neuroimaging techniques. Despite these clinical and imaging modalities, often strokes are not recognized after initial onset. As early intervention of medical or surgical therapy is often associated with improved outcomes, there is an urgent need to improve the speed and accuracy of stroke diagnosis. Stroke is a complex pathophysiological process involving; energy failure, imbalance of ion homeostasis, acidosis, intracellular calcium overload, neuronal excitotoxicity, free radical-mediated lipid oxidation, inflammatory cell infiltration, and glial cell activation. These events ultimately lead to neuronal apoptotic cell death or necrosis. In this review, we have summarized the serum biomarkers according to the pathophysiological processes of stroke, which have been intensively studied in clinical trials of stroke over the past five years, and also used Medline's 'related article' option to identify further articles. We focused on the potential biomarkers pertaining to vascular injury, metabolic changes, oxidative injury, and inflammation, and newly studied biomarkers, and discussed how these biomarkers could be used for the diagnosis or determining the prognosis of stroke.