Predictive value of D-dimer testing for the diagnosis of venous thrombosis in unusual locations: A systematic review

Cerebral venous thrombosis

Cerebral venous thrombosis is part of the so-called thrombosis in unusual sites. It is defined as an occlusion in the cerebral venous territory. Its incidence is progressively increasing, especially in developing countries. It is more frequently observed in young women, with hormonal factors such as pregnancy or hormonal contraception being significant risk factors in the development of this condition. The clinical presentation will depend fundamentally on the topography of the thrombosis, with a confirmatory diagnosis based mainly on imaging tests. The treatment generally consists of anticoagulation, and other options may be considered depending on the severity of the case. Overall, the prognosis is better than that of other intracranial vascular disorders. This review describes the current evidence available regarding cerebral venous thrombosis.

Conservatively Treated Mesenteric Vein Thrombosis in a 48-Year-Old Obese Female: A Case Report

Mesenteric vein thrombosis (MVT) is a rare pathological entity that results in compromised venous return from the intestine due to involvement, in most cases, of the superior mesenteric vein. Its diagnosis is not straightforward, since the findings on physical examination are often disproportionate to the patient's pain complaints, leading to it being undervalued by clinicians. The patient is a 48-year-old female with a medical history of essential arterial hypertension, dyslipidemia, class II obesity, and Hashimoto's thyroiditis. She also had a family history of gastric and colon cancer, with an age at diagnosis of over 70 years. She went to an appointment at a primary care facility for abdominal pain located in the left hypochondrium and flank, with ipsilateral lumbar irradiation and no other accompanying symptoms. Physical examination revealed a globose, depressible abdomen, painful on palpation of the left quadrants, with no other associated signs of peritoneal irritation. Due to suspicion of acute diverticulitis, the patient was referred to the emergency department (ED) for assessment by general surgery. In the emergency department, given the patient's body type and the fact that the physical examination findings were disproportionate to her symptoms, an abdominal and pelvic computed tomography (CT) scan was ordered, which revealed complete thrombosis of the entire length of the inferior mesenteric vein, with a focal extension of the thrombus, partially obstructing the confluence with the superior mesenteric and portal veins. Various complementary diagnostic tests were requested, which revealed no clinically significant findings, and obesity was therefore identified as the only risk factor. In this context, the patient started anticoagulation with warfarin, with the indication that it should be ad aeternum. To date, the patient remains asymptomatic, and there have been no new thrombotic events. Given the high morbidity and mortality rates of this pathological entity, it is imperative that clinicians are trained to recognize the typical signs of mesenteric venous thrombosis, in the characteristic epidemiological context, in order to establish a timely diagnosis and carry out early targeted therapeutic intervention.

Cerebral venous thrombosis in adults: a case series of 35 patients from a tertiary hospital

OBJECTIVE

To describe the baseline characteristics, clinical presentation, imaging tests and outcomes and identify potential prognostic factors in a cohort of patients diagnosed with cerebral venous thrombosis (CVT).

PATIENTS AND METHODS

Retrospective, single-center, observational study that included adult patients diagnosed with CVT from January 2016 to December 2020. The variables were reviewed through electronic medical records.

RESULTS

A total of 35 patients were included and the median age at diagnosis was 50.3 (+/- 17.8) years, the majority being women (74.4%). Almost 95% of the patients presented at least one risk factor for the development of CVT. Heparins were used for the acute phase in 97.1%; among them, 75% were low molecular weight heparins. The compound event (death, intensive care unit admission, National Institute of Health Stroke Scale at discharge >3, CVT recurrence, major bleeding, or the presence of complications) within the first two weeks occurred in 28.6% (10 patients). During the mean follow-up of 3.3 years, 14.3% died (among them, only one patient´s death was caused by CVT), one patient had major bleeding and no patient presented recurrence of CVT.

CONCLUSIONS

In our cohort, CVT affected more frequently young women with at least one risk factor for the development of CVT. The presence of edema on CT and corticosteroid treatment were associated with poor short-term prognosis. A good long-term prognosis was observed in terms of mortality, recurrence, and bleeding.

[Clinical characteristics and presentation form in patients with venous thromboembolism and negative or weakly positive D-dimer]

INTRODUCTION

D-dimer has a high negative predictive value for the diagnosis of venous thromboembolic disease (VTE). However, VTE has been reported in the presence of normal D-dimer values.

METHODS

This is a prospective observational study in patients with VTE from Hospital Gregorio Marañón between 2001 and 2022, comparing the characteristics of clinical presentation based on D-dimer levels (<500 ng/mL vs. ≥500 ng/mL).

RESULTS

A total of 2582 patients were found, 333 patients (12.9%) presented negative or weakly positive D-dimer levels. They were significantly younger (57.9 vs. 65.3 years), with a lower prevalence of comorbidities (ischemic heart disease, dementia, and chronic kidney disease), and a greater family history of VTE (8.4% vs. 5.2%) and thrombophilia (11.7% vs. 7.8%). They presented significantly less dyspnea (57.6% vs. 75.4%), syncope (3% vs. 13.5%), less thrombotic load, elevated NT-pro-BNP (22.0% vs. 48.2%), and right ventricle dilatation (8.1% vs. 30.0%).

CONCLUSION

Patients with VTE and low D-dimer levels at diagnosis were younger, with milder clinical presentation and lower thrombotic load; but they presented a higher prevalence of thrombophilia and a family history of VTE.

Mesenteric venous thrombosis

Mesenteric vein thrombosis (MVT) is a rare condition that can present acutely, subacutely, or chronically. MVT can be isolated or within a splanchnic thrombosis (spleno-porto-mesenteric). Symptomatic cases usually present as nonspecific abdominal pain, with or without signs of intestinal ischemia, and the diagnosis is usually made by imaging test (abdominal CT or MRI) in patients with high clinical suspicion. An early clinical-surgical approach is recommended to screen those patients with warning signs and who benefit from an exploratory laparotomy in addition to anticoagulant treatment, which is the cornerstone of medical treatment. MVT is usually associated with prothrombotic states, with hematological disorders (myeloproliferative syndromes and/or JAK2 gene mutations) being of special clinical relevance. On the other hand, the 5-year survival rate is 70-82% and early overall 30-day mortality from MVT can reach 20-32%.

Nomogram for Predicting Portal Vein Thrombosis in Cirrhotic Patients: A Retrospective Cohort Study

AIM

Portal vein thrombosis (PVT) is a common complication in cirrhotic patients and will aggravate portal hypertension, thus leading to a series of severe complications. The aim of this study was to develop a nomogram based on a simple and effective model to predict PVT in cirrhotic patients.

METHODS

Clinical data of 656 cirrhotic patients with or without PVT in the First Affiliated Hospital of Soochow University and The Third Affiliated Hospital of Nantong University from January 2017 to March 2022 were retrospectively collected, and all patients were divided into training, internal and external validation cohorts. SPSS and R software were used to identify the independent risk factors and construct a predictive model. We evaluated the predictive value of the model by receiver operating characteristic (ROC) curve, calibration curve, and decision curve analyses. The feasibility of the model was further validated in the internal and external cohorts. All enrolled patients were followed up to construct the survival curves and calculate the incidence of complications.

RESULTS

The predictors of PVT included serum albumin, D-dimer, portal vein diameter, splenectomy, and esophageal and gastric varices. Based on the clinical and imaging findings, the final model served as a potential tool for predicting PVT in cirrhotic patients, with an AUC of 0.806 (0.766 in the internal validation cohort and 0.845 in the external validation cohort). The decision curve analysis revealed that the model had a high level of concordance between different medical centers. There was a significant difference between the PVT and non-PVT groups in survival analyses, with p values of 0.0477 and 0.0319 in the training and internal validation groups, respectively, along with p value of 0.0002 in the external validation group according to log-rank test; meanwhile, the median survival times of the PVT group were 54, 43, and 40 months, respectively. The incidence of recurrent esophageal and gastric variceal bleeding (EGVB) during the follow-up showed significant differences among the three cohorts (p = 0.009, 0.048, and 0.001 in the training, internal validation, and external validation cohorts, respectively).

CONCLUSION

The nomogram based on our model provides a simple and convenient method for predicting PVT in cirrhotic patients. Cirrhotic patients with PVT had a shorter survival time and were prone to recurrent EGVB compared with those in the non-PVT group.

A Vicious Cycle: In Severe and Critically Ill COVID-19 Patients

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, is one of the fastest-evolving viral diseases that has instigated a worldwide pandemic. Severe inflammatory syndrome and venous thrombosis are commonly noted in COVID-19 patients with severe and critical illness, contributing to the poor prognosis. Interleukin (IL)-6, a major complex inflammatory cytokine, is an independent factor in predicting the severity of COVID-19 disease in patients. IL-6 and tumor necrosis factor (TNF)-α participate in COVID-19-induced cytokine storm, causing endothelial cell damage and upregulation of plasminogen activator inhibitor-1 (PAI-1) levels. In addition, IL-6 and PAI-1 form a vicious cycle of inflammation and thrombosis, which may contribute to the poor prognosis of patients with severe COVID-19. Targeted inhibition of IL-6 and PAI-1 signal transduction appears to improve treatment outcomes in severely and critically ill COVID-19 patients suffering from cytokine storms and venous thrombosis. Motivated by studies highlighting the relationship between inflammatory cytokines and thrombosis in viral immunology, we provide an overview of the immunothrombosis and immunoinflammation vicious loop between IL-6 and PAI-1. Our goal is that understanding this ferocious circle will benefit critically ill patients with COVID-19 worldwide.

Diagnostic accuracy of D-dimer in patients at high-risk for splanchnic vein thrombosis: A systematic review and meta-analysis

BACKGROUND

D-dimer is included in the diagnostic algorithm for deep vein thrombosis and pulmonary embolism. However, its role in the diagnosis of splanchnic vein thrombosis (SVT) is still controversial. The aim of this study was to evaluate the diagnostic accuracy of D-dimer for SVT.

METHODS

We performed a systematic review of the literature with meta-analysis (PROSPERO protocol registration number: CRD42020184300). The electronic databases MEDLINE, EMBASE, and CENTRAL were searched from inception to March 2021 week 4. Studies which evaluated D-dimer accuracy for SVT in any category of patients were selected. The index test was any D-dimer assay; the reference standard was any radiological imaging. The QUADAS-2 checklist was used for the risk of bias assessment. A bivariate random-effects regression model was used to calculate summary estimates of sensitivity and specificity.

RESULTS

12 studies (with a total of 1298 patients) evaluating the accuracy of D-dimer in patients at high risk of SVT (surgical patients, patients with liver cirrhosis or hepatocellular carcinoma) were included. None of the included studies was at low risk of bias. The weighted mean prevalence of SVT was 33.4% (95% CI, 22.5-45.2%, I2 = 94.8%). D-dimer accuracy was expressed by sensitivity 96% (95% CI, 72-100%); specificity 25% (95% CI, 5-67%); positive likelihood ratio 1.3 (95% CI, 0.9-1.9); negative likelihood ratio 0.16 (95% CI, 0.03-0.84); area under the ROC curve 0.80 (95% CI, 0.76-0.83).

CONCLUSIONS

D-dimer seems to have high sensitivity in the diagnosis of patients at high-risk for SVT. However, there is a strong need for more robust evidence on this topic.

Pulmonary Embolism in Hospitalized Patients with COVID-19: A Multicenter Study

Background

Pulmonary embolism (PE) commonly complicates SARS-CoV-2 infection, but incidence and mortality reported in single-center studies, along with risk factors, vary.

Purpose

To determine the incidence of PE in patients with COVID-19 and its associations with clinical and laboratory parameters.

Materials and Methods

In this HIPAA-compliant study, electronic medical records were searched retrospectively for demographic, clinical, and laboratory data and outcomes among patients with COVID-19 admitted at four hospitals from March through June 2020. PE found at CT pulmonary angiography and perfusion scintigraphy was correlated with clinical and laboratory parameters. The d-dimer level was used to predict PE, and the obtained threshold was externally validated among 85 hospitalized patients with COVID-19 at a fifth hospital. The association between right-sided heart strain and embolic burden was evaluated in patients with PE undergoing echocardiography.

Results

A total of 413 patients with COVID-19 (mean age, 60 years ± 16 [standard deviation]; age range, 20–98 years; 230 men) were evaluated. PE was diagnosed in 102 (25%; 95% CI: 21, 29) of 413 hospitalized patients with COVID-19 who underwent CT pulmonary angiography or perfusion scintigraphy. PE was observed in 21 (29%; 95% CI: 19, 41) of 73 patients in the intensive care unit (ICU) versus 81 (24%; 95% CI: 20, 29) of 340 patients who were not in the ICU (P = .37). PE was associated with male sex (odds ratio [OR], 1.74; 95% CI: 1.1, 2.8; P = .02); smoking (OR, 1.86; 95% CI: 1.0, 3.4; P = .04); and increased d-dimer (P < .001), lactate dehydrogenase (P < .001), ferritin (P = .001), and interleukin-6 (P = .02) levels. Mortality in hospitalized patients was similar between patients with PE and those without PE (14% [13 of 102]; 95% CI: 8, 22] vs 13% [40 of 311]; 95% CI: 9, 17; P = .98), suggesting that diagnosis and treatment of PE were not associated with excess mortality. The d-dimer levels greater than 1600 ng/mL [8.761 nmol/L] helped predict PE with 100% sensitivity and 62% specificity in an external validation cohort. Embolic burden was higher in patients with right-sided heart strain among the patients with PE undergoing echocardiography (P = .03).

Conclusion

Pulmonary embolism (PE) incidence was 25% in patients hospitalized with COVID-19 suspected of having PE. A d-dimer level greater than 1600 ng/mL [8.761 nmol/L] was sensitive for identification of patients who needed CT pulmonary angiography.

© RSNA, 2021

Online supplemental material is available for this article.

See also the editorial by Ketai in this issue.

Inflammatory Biomarkers in the Short-Term Prognosis of Venous Thromboembolism: A Narrative Review

The relationship between inflammation and venous thrombosis is not well understood. An inflammatory response may be both the cause and consequence of venous thromboembolism (VTE). In fact, several risk factors of VTE modulate thrombosis through inflammatory markers. Acute pulmonary embolism (PE) is burdened by a remarkable mortality rate, up to 34% in severely ill patients presenting with hemodynamic instability. Initial mortality risk stratification is based on hemodynamic instability. Patients with a situation of hemodynamic stability require immediate further risk assessment based on clinical, imaging, and circulating biomarkers, as well as the presence of comorbidities. Some inflammatory biomarkers have shown potential usefulness in the risk stratification of patients with VTE, especially acute PE. C-reactive protein on admission is associated with 30-day mortality and bleeding in VTE patients. P-selectin is associated with right ventricle dysfunction in PE patients and might be associated with VTE recurrences and the extension of thrombosis. Tissue factor microparticles are associated with VTE recurrence in cancer-associated thrombosis. Other inflammatory biomarkers present scarce evidence (inflammatory cytokines, erythrocyte sedimentation rate, fibrinogen, leukocyte count). In this manuscript, we will review the prognostic role of different inflammatory biomarkers available both for clinical practice and research in VTE patients.

Low level of postoperative plasma antithrombin III is associated with portal vein thrombosis after liver surgery

PURPOSE

Although decreased antithrombin-III (AT-III) is a risk factor for portal vein thrombosis (PVT) in patients with liver cirrhosis, the association between postoperative PVT and postoperative AT-III levels is unknown in patients undergoing hepatectomy.

METHODS

Patients who underwent hepatectomy between 2015 and 2018 were retrospectively analyzed. Postoperative PVT was assessed on CT at days 6-9 after hepatectomy. One-to-one propensity score (PS) matching was used to match the baseline characteristics.

RESULTS

Of the 295 patients included in this analysis, 19 patients (6.4%) were diagnosed with postoperative PVT. The AT-III level on postoperative day (POD) 3 predicted postoperative PVT with a sensitivity/specificity of 74%/59% (AUC, 0.644; cut-off value, 60%; p = 0.032). Multivariate analysis revealed that AT-III levels ≤ 60% on POD3 (OR, 3.01; 95% CI 1.02-8.89; p = 0.046), cirrhosis (OR, 5.88; 95% CI 1.92-18.0; p = 0.002) and right-sided hepatectomy (OR, 4.16; 95% CI 1.45-11.9; p = 0.0079) were significant risk factors for postoperative PVT. After PS matching, 56 patients with and without AT-III supplementation were analyzed. The two groups had a similar incidence of PVT (p = 0.489).

CONCLUSIONS

Patients with AT-III levels ≤ 60% on POD3 should be carefully followed up regarding postoperative PVT. Our results did not support the efficacy of routine AT-III supplementation for the prophylaxis of postoperative PVT.

Headache in the Emergency Department: Avoiding Misdiagnosis of Dangerous Secondary Causes, An Update

In the initial assessment of the headache patient, the emergency physician must consider several dangerous secondary causes of headache. A thorough history and physical examination, along with consideration of a comprehensive differential diagnosis may alert the emergency physician to the diagnosis of a secondary headache particularly when the history is accompanied by any of the following clinical features: sudden/severe onset, focal neurologic deficits, altered mental status, advanced age, active or recent pregnancy, coagulopathy, malignancy, fever, visual deficits, and/or loss of consciousness.

Incidence of asymptomatic deep vein thrombosis in patients with COVID-19 pneumonia and elevated D-dimer levels

AIM

An increased risk of venous thromboembolism (VTE) in patients with COVID-19 pneumonia admitted to intensive care unit (ICU) has been reported. Whether COVID-19 increases the risk of VTE in non-ICU wards remains unknown. We aimed to evaluate the burden of asymptomatic deep vein thrombosis (DVT) in COVID-19 patients with elevated D-dimer levels.

METHOD

In this prospective study consecutive patients hospitalized in non-intensive care units with diagnosis of COVID-19 pneumonia and D-dimer > 1000 ng/ml were screened for asymptomatic DVT with complete compression doppler ultrasound (CCUS). The study was approved by the Institutional Ethics Committee.

RESULTS

The study comprised 156 patients (65.4% male). All but three patients received standard doses of thromboprophylaxis. Median days of hospitalization until CCUS was 9 (IQR 5-17). CCUS was positive for DVT in 23 patients (14.7%), of whom only one was proximal DVT. Seven patients (4.5%) had bilateral distal DVT. Patients with DVT had higher median D-dimer levels: 4527 (IQR 1925-9144) ng/ml vs 2050 (IQR 1428-3235) ng/ml; p < 0.001. D-dimer levels > 1570 ng/ml were associated with asymptomatic DVT (OR 9.1; CI 95% 1.1-70.1). D-dimer showed an acceptable discriminative capacity (area under the ROC curve 0.72, 95% CI 0.61-0.84).

CONCLUSION

In patients admitted with COVID-19 pneumonia and elevated D-dimer levels, the incidence of asymptomatic DVT is similar to that described in other series. Higher cut-off levels for D-dimer might be necessary for the diagnosis of DVT in COVID-19 patients.