Raised D-dimer Levels Research Articles

Variable Performance of D-dimer Testing by Hemostasis Laboratories: The Australasian/Asia-Pacific Experience.

D-dimers represent the breakdown products of fibrin. Thus, elevated plasma D-dimers will arise following a thrombotic event, such as a deep vein thrombosis or a pulmonary embolism, and therefore, a nonelevated D-dimer is used to effectively exclude such events. D-dimers are also elevated in a range of other conditions, for example, during disseminated intravascular coagulation. D-dimer levels may also be associated with prognostic value. For example, highly raised D-dimer levels can be associated with worsening clinical features in coronavirus disease 2019. Thus, D-dimer testing represents a commonly requested hemostasis test, often performed in 24/7 laboratories. Unfortunately, D-dimer testing is neither standardized nor harmonized across manufacturers or laboratories. Indeed, considering reporting units and the magnitude of units, up to 28 different combinations may be reported by laboratories. We provide updated findings for D-dimer testing in our geographic region, using recent data from the Royal College of Pathologists of Australasia Quality Assurance Programs, an international external quality assessment program, currently with over 450 participants in the D-dimer module. Data show a wide variety of assays in use and variable outcomes in reported numerical values when assessing proficiency samples. D-dimer testing mostly comprised reagents from three main manufacturing suppliers, with a small number of users of reagents from other manufacturers. Reported results showed important differences in numerical values for the same homogeneous tested samples when normalized to a single reporting unit (e.g., mg/L). Nevertheless, despite using different test reagents and reporting, most participants uniformly identified D-dimer values as below or above a "detection" cut-off for samples that were constructed to be below or above most cut-off values. As expected, mixed findings were reported for samples containing levels around expected cut-off values. We hope that our findings, reflecting on the heterogeneity of test reagents and test data, help improve diagnostic testing for D-dimer testing and facilitate harmonization and standardization, in the future.

D-dimer: a biomarker for predicting disease severity and outcome in hospitalized children with COVID-19 and post COVID multisystem inflammatory syndrome

Background: COVID-19 has presented with varied signs and symptoms with raised inflammatory markers among which D-dimers have been highlighted right from the beginning. Objectives were to analyze the relationship of D-dimers with the disease severity and outcome of children with COVID-19 and MIS-C in a developing country. Methods: It was a retrospective study conducted at a pediatric tertiary care hospital from March 2020 to November 2021. Clinical and laboratory details of confirmed COVID-19 and post COVID-19 MIS-C cases were recorded. D-dimer testing was performed using Chemiluminescence technique. It’s relation with disease severity and predictive role for in-hospital mortality were established by using ROC curves and cut-off values were calculated by using SPSS-24. Results: Of 272 children, 182 were of COVID-19 and 90 were of MIS-C. The mean age for COVID-19 and MIS-C patients was 5.4±4.8 years and 6.4±3.5 years respectively. Mild disease was seen in 33% cases while 17.6% were critical and 56.2% had some under lying comorbidity at presentation. Mean D-dimers were significantly higher in children with severe disease, who required ICU admission and non-survivors as compared to those with mild or moderate disease, not requiring ICU care and survivors, both in COVID-19 and MIS-C patients. ROC curve identified D-dimer value of ≥4.58 µg/ml (AUC=0.845) for COVID-19 cases and ≥4.73 µg/ml (AUC=0.682) for MIS-C patients as predictive of mortality. Conclusions: Raised D-dimer level is a reliable predictor of disease severity and outcome in children with COVID-19 and MIS-C. The D-dimer value of 4.58 µg/ml for COVID-19 cases and 4.73µg/ml for MIS-C patients was found to be the cut-off levels for predicting mortality

D-dimers in omicron versus delta: A retrospective analysis.

Infection with SARS-CoV-2 has shown to cause an increase in D-dimers, which correlate with severity and prognosis for in-hospital mortality. The B.1.617.2 (delta) variant is known to cause a raised D-dimer level, with data on D-dimers in the B.1.1.529 (omicron) variant being scarce. To determine the effect of age, gender and SARS-CoV-2 variant on the D-dimer in South Africans admitted to tertiary medical centres from May 2021 to December 2021. The study was performed retrospectively on 16 010 adult patients with a SARS-CoV-2 infection. Age, gender, SARS-CoV-2 PCR and D-dimer levels on admission were collected from two national laboratories. Admissions from 01 May 2021 to 31 October 2021 were classified as B.1.617.2, whereas admissions from 01 November 2021 to 23 December 2021 were classified as B.1.1.529 infections. Omicron infections had a median D-dimer level of 0.54 µg/mL (95% CI: 0.32, 1.08, p < 0.001). Multivariable regression analysis showed that infection with omicron had a 34.30% (95% CI: 28.97, 39.23) reduction in D-dimer values, compared with delta infections. Middle aged, aged and aged over 80 years had D-dimer results greater than the adult baseline (42.6%, 95% CI: 38.0, 47.3, 124.6%, 95% CI: 116.0, 133.7 and 216.1%, 95% CI: 199.5, 233.3). Males on average had a 7.1% (95% CI: 4.6, 9.6) lower D-dimer level than females. Infection with the B.1.1.529 variant, compared with B.1.617.2 variant, had significantly lower D-dimer levels, with age being a more significant predictor of D-dimer levels, than gender and SARS-CoV-2 variant of infection. This study provides novel insight into the hypercoagulable impact of various SARS-CoV-2 variants, which can guide the management of patients.

Case report: Kaposi hemangioendothelioma of the right upper limb with the Kasabach–Merritt phenomenon: A potentially lethal diagnostic challenge

Kaposi hemangioendothelioma (KHE) is a rare vascular neoplasm that presents usually within the first year of life. Because of its rarity and complexity, there is often a delay in diagnosis. KHE could be associated with a life-threatening consumptive coagulopathy named the Kasabach-Merritt phenomenon (KMP). Here, we present the case of a 2-month-old girl who presented with progressive redness and swelling of her right upper limb over 6 weeks. Multiple health practitioners misdiagnosed her condition as an insect bite, cellulitis, and necrotizing fasciitis and gave treatment accordingly, which proved futile. A full blood count revealed bicytopenia of anemia and thrombocytopenia, a normal coagulation cascade, low fibrinogen, and raised D-Dimer levels. The imaging was suggestive of a high-flow vascular tumor likely to be a KHE. Subsequently, she was started on single-agent oral sirolimus with a dose increment to achieve satisfactory therapeutic levels and was treated for 1 year. She successfully completed the treatment regimen and had only transient hypertriglyceridemia, which resolved upon the completion of treatment. Currently, she is in remission 3 years after treatment. Keeping her case as an example, we would like to highlight the potentially lethal misdiagnosis of KHE with KMP, the importance of an early diagnosis of this condition, and the successful treatment outcome with single-agent sirolimus.

Raised D-dimer Level among COVID-19 Patients in a Tertiary Care Hospital: A Descriptive Cross-sectional Study.

Serum D-dimer is a protein fragment generated during the final phase of clot formation. Increased serum D-dimer levels indicate the hemostatic change in patients, likely related to the prothrombotic switch. As the world is battling with the damaging effect of coronavirus disease, it is very important to find out the early and effective predictors of prognosis to improve the management of COVID-19 patients. Thus, our study aims to find out the prevalence of increased D-dimer levels in coronavirus disease patients. A descriptive cross-sectional study was conducted on a total of 235 patients admitted in the COVID ward and COVID Intensive Care Units at a tertiary care hospital from July 2020 to August 2021 after getting ethical approval (Reference number: 401/2020) from the Institutional Review Committee. A convenience sampling method was used for sample collection. The highest recorded values for D-dimer during the hospital stay were taken for data collection. The data were entered in Microsoft Excel 2013 and analyzed using Statistical Package for the Social Sciences version 16.0. Point estimate at 95% Confidence Interval was calculated along with frequency, proportion, mean and standard deviation. Among 235 patients, elevated D- dimer level was in 175 (74.46%) (68.88-80.04 at 95% Confidence Interval). Majority of the patients were males 136 (77.71%) whereas 39 (22.28%) of the patients were females. The prevalence of raised D-dimer levels was quite higher in our studies compared to other studies done in different parts of the world. Thus, serum D-dimer level may serve as an early marker in improving the management of patients with coronavirus disease. corona virus disease; d-dimer; disease severity.

Pathological findings in COVID-19: A conventional autopsy-based study from India.

Background & objectives:Autopsy study has been considered the gold standard method for studying the effects of any disease on the body. Since COVID-19 is a novel disease, autopsy is crucial to understand its pathophysiology. This study was conducted to analyze the microscopic and macroscopic findings of various organs in COVID-19 and to associate those findings with clinical observations and laboratory findings.Methods:Conventional invasive autopsies were performed on 33 patients with COVID-19 from September 7, 2020 to December 23, 2020. All the organs were removed by routine dissection techniques and preserved in 10 per cent formalin. The tissues were processed and stained according to standard practices using haematoxylin-eosin (H & E) and periodic acid-schiff (PAS) stain.Results:The study included 28 males and 5 females with a median age of 61 yr (range 30-90 yr). Massive pulmonary oedema and thrombi in the lungs were the characteristic features macroscopically. On microscopic examination, diffuse alveolar damage in the exudative/proliferative phase was found in 29 (87.88%) cases. Among the other notable microscopic findings were bronchopneumonia and lung abscesses due to secondary bacterial infection (n=17, 51.52%), acute tubular injury (n=21, 63.64%) and thrombi in the lungs, heart, and kidneys.Interpretation & conclusions:COVID-19 primarily affected the respiratory and the renal systems in the vast majority of severely affected patients in our study. We also found signs of hypercoagulability, as evidenced by widespread thrombi in multiple organs, along with a raised d-dimer level and a hyperinflammatory state manifested by elevated inflammatory markers. Our autopsy findings and altered laboratory investigations support the role of immune-mediated cellular injury along with direct virus-mediated cellular damage.

D-dimer as a safe, convenient and easily available biomarker, when combined with conventional sentinel node biopsy in clinically node negative breast cancer to assess metastatic disease in axilla and reduce false negative results

Background: Breast cancer is frequently associated with activation of the hemostatic system and the extent of this activation correlates with a more advanced tumor stage. D-dimer is a biomarker that indicates the activation of hemostasis and fibrinolysis.Methods: This is a prospective, observational, analytical study in which we compare plasma D-dimer levels among three groups’ i.e., healthy subjects, benign patients and breast cancer patients. We have also evaluated plasma D-dimer levels in patients with lymphadenopathy and in those patients who did not have palpable lymph nodes. Plasma D-dimer levels were further characterized based on TNM classification in breast cancer patients where quantitative D-dimer levels were correlated with clinical stage grouping.Results: Through our study we have observed that D-dimer level is inexpensive and a convenient method for diagnosis and prognosis of breast cancer. We have used a control group so as to evaluate a more accurate result. Comparison between benign and malignant lesions was made and we have achieved a significant p value, which proved our study positive for raised D-dimer levels in cancer breast.Conclusions: D-dimer proves to be a safe, convenient and easily available biomarker which can be combined with conventional sentinel node biopsy in clinically node negative breast cancer to assess metastatic disease in axilla and reduce false negative results. Plasma D-dimer level was positively correlated with clinical stage of solid cancers.

“D-DIMER LEVEL AS PREDICTIVE BIOMARKER FOR COVID-19 DISEASE SEVERITY: AN ANALYSIS”

Objectives- COVID-19 is now a global pandemic and it was rst reported in Wuhan, China, in December 2019. In is observed in few critically ill patients that that he course of disease is rapid and with in short period of time the clinical condition may worsen. Deranged coagulation prole, including elevation of D-dimer level are identied during course of COVID-19 infection. Raised serum level of D dimer is associated with increased mortality in COVID19 Patients. Methods- The data of 128 COVID 19 patients was retrospectively collected and analyzed. After categorization of patients into two groups the optimal cutoff value of D-dimer on admission was evaluated by receiver operator characteristic (ROC) curve. Result- Out of total 128 enrolled in the study, 81(63.28%) patients were in non severe group and 47(36.72%) patients in severe group and mean value of D-dimer in non severe group and severe group was 2.17 (2.78)mg/L, and 11.26 (7.56)mg/L respectively. The area under the curve (AUC) of ROC curve was 0.886 (95% CI 0.818-0.954; p value&lt;0.0001) with optimal threshold value was 2.345 mg/L. Conclusion- In COVID-19 patients D-dimer value ≥ 2.345 mg/L can be used to effectively predict the severity of disease. A signicant association has been found in raised D-dimer level and disease severity.

The prevalence of pulmonary embolism in non-hospitalised de-isolated patients diagnosed with mild COVID-19 disease.

Pulmonary embolism (PE) is a known complication of COVID-19 disease. The mechanism of thromboembolic events appears to be stimulated by excessive thrombin production, inhibition of fibrinolysis and deposition of antiphospholipids and thrombi, as well as microvascular dysfunction in multiple vascular beds. The occurrence of PE has been well demonstrated in hospitalised patients with severe disease. Very few data are available on its incidence or prevalence in non-hospitalised patients diagnosed with a milder form of the disease. To assess the prevalence of PE in non-hospitalised patients diagnosed with mild COVID-19 who presented with raised D-dimer levels and persistent or new-onset cardiopulmonary symptoms. This was a retrospective study conducted in the Department of Nuclear Medicine at Universitas Academic Hospital, Bloemfontein, South Africa. We reviewed the studies of 65 non-hospitalised patients with COVID-19 referred to the department from July 2020 to January 2021 for a perfusion-only single-photon emission computed tomography/computed tomography (SPECT/CT) study or a ventilation/perfusion (VQ) SPECT/CT study. All 65 patients had raised D-dimer levels with persistent, worsening or new-onset cardiopulmonary symptoms after the diagnosis of COVID-19. Sixty-five patients were studied. The median (interquartile range) age was 46 (41 - 54) years and the majority (88.2%) were female. There were 22 patients (33.8%) with lung perfusion defects in keeping with PE. Two of these patients had a false-negative computed tomography pulmonary angiography (CTPA) study for PE performed the same day as their VQ SPECT/CT study. We confirm a high prevalence of PE in non-hospitalised patients diagnosed with mild COVID-19 who presented with raised D-dimer levels and persistent or new-onset cardiopulmonary symptoms. We recommend that irrespective of disease severity, hospitalised and non-hospitalised patients with COVID-19 presenting with persistent or new-onset cardiopulmonary symptoms and raised D-dimer levels should be investigated further for PE.

ROLE OF D-DIMER AND SERUM LDH IN DETERMINING SEVERITY, PROGRESSION AND PROGNOSIS OF COVID -19 PATIENTS.

Background: D- dimer and serum LDH is inflammatory marker which can be used to determine severity, progression and prognosis of covid 19.&#x0D; Aim: To establish role of D-dimer and serum LDH in determining severity, progression and prognosis of covid 19 patients.&#x0D; Result: The study population included 43 males and 32 females having COVID- 19 infection. The study showed that raised D-dimer levels were associated with increased coagulation activity and thereby poor prognosis. The study also showed that all the patients with raised serum LDH levels had more severe form of disease leading to rapid disease progression and prolonged hospital stay.&#x0D; Conclusion: Any abnormal rise in D-dimer levels along with other inflammatory markers suggests that the patient requires vigorous anticoagulation therapy. The serum LDH’s elevated levels are usually employed in determining the disease progression from mild to moderate and severe forms.&#x0D; Keyword: covid 19, D-dimer, serum LDH

Analysis of the Coagulation Profile in Children with HIV Infection-Effect of Disease and Anti Retroviral Therapy.

The pathogenesis of hypercoagulability in HIV infection is multifactorial and usually more than one factor is responsible for a thromboembolic episode. The present study was conducted to evaluate the effect of HIV infection and antiretroviral therapy on various coagulation parameters in paediatric patients. Forty two newly diagnosed paediatric patients with HIV infection who were enrolled at the Anti-Retro viral Therapy (ART) centre of Kalawati Saran Children's Hospital were included in the study. The patients were grouped into 4 clinical stages according to the WHO clinical staging of HIV disease. Coagulation tests [PT, aPTT, fibrinogen, D-Dimer and coagulation inhibitors i.e. Protein C (PC), Protein S (PS) and antithrombin III (AT III), Lupus anticoagulant (LA) and Anti phospholipid antibody (APLA)] were performed in all the patients at the time of diagnosis and repeated after 6months. All the patients were started on antiretroviral therapy within 2months of their diagnosis. At the time of diagnosis, prolonged PT and aPTT were observed in 30.9% and 23% of the cases respectively. Hyperfibinogenemia was seen in 11.9% of patients. D-Dimer was raised in 83.3% of patients. PS, PC & AT activities were reduced in 90.4%, 42.8% & 11.9% of cases respectively. A reduction in the PC and AT activity was seen from clinical stage 1 to 4, but the change was not statistically significant. On follow up after 6months, a statistically significant reduction in the level of fibrinogen and D-Dimer was seen. Even though there was improvement in the activity of all the coagulation inhibitor after 6months, statistically significant improvement was seen only for PS. The current study shows that HIV produces a hypercoagulable state in children. Raised d-dimer level and deficiency of natural anticoagulants contribute to the thrombophilic state.

Systematic testing for venous thromboembolism in hospitalized patients with COVID-19 and raised D-dimer levels

BackgroundHospitalized patients with COVID-19 and raised D-dimer levels have high rates of venous thromboembolism (VTE). MethodsWe used data from hospitalized patients with COVID-19 that were tested for pulmonary embolism (PE) or deep vein thrombosis (DVT) because of raised D-dimer levels. We aimed to identify patients at increased risk for VTE. ResultsFrom March 25 to July 5th, 2020, 1,306 hospitalized patients with COVID-19 and raised D-dimer levels underwent testing for VTE in 12 centers. In all, 171 of 714 (24%) had PE, and 161 of 810 (20%) had DVT. The median time elapsed from admission to VTE testing was 12 days, and the median time from D-dimer measurement to testing 2 days. Most patients with VTE were men (62%), mean age was 62 ​± ​15 years, 45% were in an intensive care unit. Overall, 681 patients (52%) received VTE prophylaxis with standard doses, 241 (18%) with intermediate doses and 100 (7.7%) with therapeutic doses of anticoagulants. On multivariable analysis, patients with D-dimer levels >20 times the upper normal range (19% of the whole cohort) were at increased risk for VTE (odds ratio [OR]: 3.24; 95%CI: 2.18–4.83), as were those with a platelet count <100,000/μL (OR: 4.17; 95%CI: 1.72–10.0). ConclusionsHospitalized patients with COVID-19 and D-dimer levels >20 times the upper normal range were at an increased risk for VTE. This may help to identify what patients could likely benefit from the use of higher than recommended doses of anticoagulants for VTE prophylaxis.

Causal Relationship between D-Dimers and Disease Status in Chronic Spontaneous Urticaria and Adjuvant Effect of Oral Tranexamic Acid.

Introduction:Besides autoimmunity, recent studies have reported a role of the coagulation cascade in the pathogenesis of urticaria. However, the real-world data regarding the utility of measuring D-dimer levels in patients chronic spontaneous urticaria (CSU) is missing. This study was done to evaluate the D-dimer levels of CSU patients and study the relationship between raised D-dimer levels and disease severity and treatment response.Methods:A retrospective chart review of all adult (>18 years) CSU patients was done. Complete clinicodemographic data regarding the disease duration and treatment response were noted. Urticaria activity score over 7 days (UAS7) was used to assess disease severity.Results:Of total 141 patients, D-dimer levels were raised in 46 CSU patients (32.6%) with mean D-dimer levels at baseline in these patients being 329.53 ± 546.94 ng/ml. The proportion of patients with raised plasma D-dimer levels was higher in patients with severe CSU (12.9%, 27.2%, 54.5% in mild, moderate, and severe disease, respectively P < 0.001). No significant differences were found between those with raised D-dimers and those having normal D-dimer levels with respect to age, gender, presence of angioedema, history of atopy, presence of thyroid abnormality, ASST/APST positivity, and serum IgE.Conclusion:D-dimer levels parallels the disease severity and can help predict the need for higher dose of antihistamines and second-line therapy in CSU patients.

Haematological manifestations of COVID 19 And their prognostic significance- A Cross-Sectional Study

SARS-CoV2 started as pneumonia of unknown aetiology in Wuhan, China. Considered a respiratory pathogen primarily initially, COVID 19 is now identified as a systemic infection with significant effects on the hematopoietic system. Lymphopenia, peak platelet/ lymphocyte ratio and neutrophil/lymphocyte ratio are some of the parameters that could be considered as prognostic markers of the disease. Disseminated intravascular coagulation, along with elevated D-dimer levels, are commonly encountered and are usually associated with a worsening clinical picture. IL-6, C reactive protein and Lactate Dehydrogenase with high serum prolactin and serum ferritin levels project a dismal outcome. Venous thromboembolism occurs in both ambulatory and bedridden patients making thromboprophylaxis with LMWH popular. To correlate haematological parameters like lymphopenia, deranged coagulation profile and elevated d- dimer levels with the outcome (recovery or death) of the patients infected with SARS-CoV-2. In this prospective cross-sectional study, data will be gathered from patients found to be positive for COVID 19 with the duration of the study being four months. Lymphopenia, elevated D-dimer levels and deranged coagulation profile are expected in patients with COVID-19. Haematological parameter like lymphopenia raised D-dimer levels, and deranged coagulation profile are associated with poor prognosis in COVID 19.

Pulmonary embolism in COVID-19: Clinical characteristics and cardiac implications

BackgroundThe thrombogenic potential of Covid-19 is increasingly recognised. We aim to assess the characteristics of COVID-19 patients diagnosed with pulmonary embolism (PE). MethodsWe conducted a single centre, retrospective observational cohort study of COVID-19 patients admitted between 1st March and 30th April 2020 subsequently diagnosed with PE following computed tomography pulmonary angiogram (CTPA). Patient demographics, comorbidities, presenting complaints and inpatient investigations were recorded. ResultsWe identified 15 COVID-19 patients diagnosed with PE (median age = 58 years [IQR = 23], 87% male). 2 died (13%), both male patients >70 years. Most common symptoms were dyspnoea (N = 10, 67%) and fever (N = 7, 47%). 12 (80%) reported 7 days or more of non-resolving symptoms prior to admission. 7 (47%) required continuous positive airway pressure (CPAP), 2 (13%) of which were subsequently intubated. All patients had significantly raised D-dimer levels, lactate dehydrogenase (LDH), C-reactive protein (CRP), ferritin and prothrombin times. The distribution of PEs correlated with the pattern of consolidation observed on CTPA in 9 (60%) patients; the majority being peripheral or subsegmental (N = 14, 93%) and only 1 central PE. 10 (67%) had an abnormal resting electrocardiogram (ECG), the commonest finding being sinus tachycardia. 6 (40%) who underwent transthoracic echocardiography (TTE) had structurally and functionally normal right hearts. ConclusionOur study suggests that patients who demonstrate acute deterioration, a protracted course of illness with non-resolving symptoms, worsening dyspnoea, persistent oxygen requirements or significantly raised D-dimer levels should be investigated for PE, particularly in the context of COVID-19 infection. TTE and to a lesser degree the ECG are unreliable predictors of PE within this context.

ROLE OF D-DIMER IN DIAGNOSIS OF ACUTE CEREBRAL VENOUS THROMBOSIS

Background: Cerebral venous thrombosis (CVT) is a long-term debilitating vascular brain disease with high morbidity and mortality. Plasma levels of D-dimer are shown to be elevated and sensitive for the diagnosis of cerebral venous thrombosis (CVT). Objective: To evaluate the usefulness of plasma D-dimer levels in diagnosis of cerebral venous thrombosis. Patients and methods: This case-control study was conducted on two groups, patient group (40 patients) with CVT, and control group (10 patients) without CVT. All patients were subjected to full history and complete general and neurological examination focusing on headache either isolated or with symptoms of increased intracranial pressure (nausea/vomiting, papilledema, visual disturbance, disturbance of consciousness), focal motor deficit, cranial nerve palsy, or seizure. Fundus examination was done to detect papilledema and brain MRI and MRV to detect CVT, and determine the affected sinus. D-dimer levels were measured by the rapid sensitive D-dimer assay. The study was done at Department of Neurology, Al-Hussein and SayedGalalUniversityHospitals, Cairo, Egypt. Results: Among patient group, 30 (75%) patients were females, while 10 (25%) patients were males, and the mean of age was 27.4 years. The common presenting symptom was headache with blurred vision in 21 (52.5%) patients, followed by focal seizures in 10 (25%) patients. The most common sinus involved was right (Rt.) transverse sinus in 14 (35%) patients. Twenty-seven (67.5 %) patients had papilledema. D-dimer test was positive in 39 (97.5%) patients in patient group, while in the control group 1 patient (10%) was positive and 9 patients (90%) were negative. Conclusion: Raised D-dimer level was often helpful for early diagnosis of CVT and an important screening tool to determine the early need of neuroimaging in patients who were suspected to have CVT. Negative D-dimer test did not exclude CVT, but indicated that acute CVT was very unlikely.

ROLE OF D-DIMER IN DIAGNOSIS OF ACUTE CEREBRAL VENOUS THROMBOSIS

Background: Cerebral venous thrombosis (CVT) is a long-term debilitating vascular brain disease with high morbidity and mortality. Plasma levels of D-dimer are shown to be elevated and sensitive for the diagnosis of cerebral venous thrombosis (CVT). Objective: To evaluate the usefulness of plasma D-dimer levels in diagnosis of cerebral venous thrombosis. Patients and methods: This case-control study was conducted on two groups, patient group (40 patients) with CVT, and control group (10 patients) without CVT. All patients were subjected to full history and complete general and neurological examination focusing on headache either isolated or with symptoms of increased intracranial pressure (nausea/vomiting, papilledema, visual disturbance, disturbance of consciousness), focal motor deficit, cranial nerve palsy, or seizure. Fundus examination was done to detect papilledema and brain MRI and MRV to detect CVT, and determine the affected sinus. D-dimer levels were measured by the rapid sensitive D-dimer assay. The study was done at Department of Neurology, Al-Hussein and SayedGalalUniversityHospitals, Cairo, Egypt. Results: Among patient group, 30 (75%) patients were females, while 10 (25%) patients were males, and the mean of age was 27.4 years. The common presenting symptom was headache with blurred vision in 21 (52.5%) patients, followed by focal seizures in 10 (25%) patients. The most common sinus involved was right (Rt.) transverse sinus in 14 (35%) patients. Twenty-seven (67.5 %) patients had papilledema. D-dimer test was positive in 39 (97.5%) patients in patient group, while in the control group 1 patient (10%) was positive and 9 patients (90%) were negative. Conclusion: Raised D-dimer level was often helpful for early diagnosis of CVT and an important screening tool to determine the early need of neuroimaging in patients who were suspected to have CVT. Negative D-dimer test did not exclude CVT, but indicated that acute CVT was very unlikely.

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry.

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy. We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel). In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n=171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n=382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors. Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences.

D-Dimer Levels and Risk of Recurrence Following Provoked Venous Thromboembolism: Findings from the Riete Registry

Background. Patients with venous thromboembolism (VTE) secondary to transient risk factors or cancer may develop VTE recurrences after discontinuing anticoagulant therapy. Identifying at-risk patients could help to guide the ideal duration of anticoagulant therapy in these patients.Methods. We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. The proportion of patients with raised d-dimer levels was determined and the hazard ratio (HR) for VTE recurrences compared to those with normal levels was calculated. Univariate and multivariate analyses of factors associated with VTE recurrence were performed.Results. 3 606 patients were identified in the database in April 2018: 2 590 had VTE after a transient risk factor and 1016 had a cancer. D-dimer levels were measured after discontinuing anticoagulation in 1 732 (67%) patients with transient risk factors and 732 (72%) patients with cancer-associated VTE and these patients formed the cohort in which recurrent VTE rate was calculated. D-dimers and were elevated in 551 (31.8%) of patients with a transient risk factor and were normal in 1181 (68.2%). In the cancer-associated group, d-dimers were elevated in 398 (54.3%) and normal in 334 (45.7%) patients. The adjusted hazard ratio for recurrent VTE was: 2.32 (95%CI: 1.55-3.49) in patients with transient risk factors and 2.23 (95%CI: 1.50-3.39) in those with cancer.Conclusions. Patients with raised d-dimer levels after discontinuing anticoagulant therapy for provoked or cancer-associated VTE are at increased risk for recurrent VTE and death. Future studies could target these patients for extended anticoagulation. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

False Positive Perfusion/Ventilation SPECT Study for Pulmonary Embolism in a Patient with Fontan Circulation.

Fontan circulation is the consequence of an operation that results in the flow of systemic venous blood to the lungs without passing through a ventricle. An 18-year old man with a history of congenital heart disease surgically treated with Fontan circulation, presented with pleuritic chest pain and a raised D-dimer level. Perfusion/ventilation SPECT was performed to exclude the possibility of pulmonary embolism (PE) that showed unilateral reduced perfusion of the left lung with a mismatched right upper lobe defect, suspicious of PE. However, subsequent computed tomography pulmonary angiogram and clinical follow-up excluded the possibility of PE, emphasizing the need for knowledge of potential pitfalls to avoid false interpretations. Given the fact that adult congenital heart disease population is growing, with the majority having single ventricle/Fontan circulation and being at risk for thromboembolic disease, knowledge of the perfusion pattern pitfalls is important to avoid false interpretation and preventing the misdiagnosis of PE in patients with Fontan physiology.