D-dimer Test Research Articles

Prevalence, Risk Factors of Deep Venous Thrombosis in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease: A Cross-sectional Study

Introduction: It is important to increase awareness and identify the predictors of Deep Vein Thrombosis (DVT) in Chronic Obstructive Pulmonary Disease (COPD) patients presenting with worsening dyspnoea, as they are at a high-risk for Venous Thromboembolism (VTE) due to immobility, inflammation, and comorbidities. Aim: To determine the prevalence of DVT in hospitalised patients with acute exacerbation of COPD, as well as to identify associated risk factors for DVT in this group. Materials and Methods: A cross-sectional study was conducted from March 2021 to June 2022 in the Department of Respiratory Medicine at Vydehi Institute of Medical Sciences and Research Centre, Bengaluru, Karnataka, India. The sample population consisted of hospitalised patients with acute exacerbation of COPD who were aged over 40 years. All patients underwent routine blood investigations, Electrocardiograph (ECG), echocardiogram, arterial blood gas analysis, D-dimer test, chest radiograph, and lower-limb venous Doppler. Risk assessment was performed using the Modified Well’s criteria for DVT, and pretest probability was determined for all patients. The Chi-square test was used as a test of significance, with a p-value <0.05 considered statistically significant in all analyses. Results: The mean age of the study population was found to be 60.80±10.21 years. Among the 74 patients included in the study, it was found that 3 (4.05%) patients had DVT. There was no statistically significant difference between the DVT and non DVT groups regarding age, sex, obesity, modified Medical Research Council (mMRC) grade of breathlessness, smoking status, severity of airflow obstruction in spirometry, COPD class, type of respiratory failure, and presence of comorbidities. However, there was a statistically significant difference between the DVT and non DVT groups in terms of elevated D-dimer (>500 ng/mL), history of immobilisation for more than three days, and Modified Wells’ score (>2). Conclusion: Patients with acute exacerbation of COPD, associated with a significant history of immobilisation and high D-dimer values, along with a high-risk pretest probability using clinical predictors such as the Modified Wells’ score for DVT, should be considered for evaluation of VTE and early initiation of prophylactic anticoagulation therapy to prevent Pulmonary Thromboembolism.

Coagulation Testing in Real-World Setting: Insights From a Comprehensive Survey.

The objective of this survey was to gain a real-world perspective on coagulation testing by evaluating the availability of various coagulation laboratory tests, assessing specific analytic and postanalytic steps in clinical laboratories in Korea.Participants were surveyed using a 65-question questionnaire specifically focused on their coagulation testing practices related to prothrombin time (PT), activated partial thromboplastin time (aPTT), plasma-mixing studies, lupus anticoagulant (LA) tests, platelet function tests, coagulation factor assays, and the composition of hemostasis and thrombosis test panels. The survey was performed between July and September 2022.The survey achieved a 77.9% (81 of 104) response rate. PT or aPTT tests were performed directly at all participating institutions, followed by D-dimer and fibrinogen tests, platelet function test, and plasma-mixing studies in order of frequency. Variations existed in the performance of mixing test and LA assessment. Patterns of coagulating testing differed depending on the size of the hospital. The survey revealed that most laboratories conducted coagulation tests following the international guidelines such as Clinical Laboratory Standards Institute guidelines and the Korean Laboratory Certification system. However, some coagulation tests, including mixing test and LA tests, are yet to be standardized in Korea.Continuous education on coagulation test methods and internal and external quality control are required to encourage laboratories to enhance the performance of coagulation testing.

Lessons learnt from inappropriate D-dimer testing: Case report

Lessons learnt from inappropriate D-dimer testing: Case report

Pulmonary embolism risk stratification: external validation of the 4-level Clinical Pretest Probability Score (4PEPS)

BackgroundThe 4-level clinical pretest probability score (4PEPS) was recently introduced as a clinical decision rule for the diagnosis of pulmonary embolism (PE). Based on the score, patients are classified into clinical pretest probability categories (c-PTP). The “very low” category aims at excluding PE without further testing; “low” and “moderate” categories require D-dimer testing with specific thresholds, while patients with a “high” pretest directly proceed to imaging. ObjectivesTo provide further external validation of the 4PEPS model. MethodsThe 4PEPS was applied to a previously collected prospective database of 756 patients with clinically suspected PE enrolled from European emergency departments in 2002 to 2003. The safety threshold for the failure rate in our study was calculated at 1.95% based on a 26% prevalence of PE in our study, as per the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee guidance. ResultsPatients were classified as follows: 90 (12%) in the very low c-PTP group, of whom 5 (5.6%; 95% CI, 2.4%-12.4%) had PE; 363 (49%) in the low c-PTP group, of whom 34 had PE (9.4%); 246 (34%) in the moderate c-PTP group, of whom 124 (50%) had PE; and 35 (5%) in the high c-PTP group of whom 30 (86%) had PE. Overall, the failure rate of the 4PEPS was 9/734 (1.2%; 95% CI, 0.59%-2.23%) Overall, 9 out of 734 patients (1.2%; 95% CI, 0.59%-2.23%) were diagnosed with PE despite a negative 4PEPS rule; 5 (5.6%) from the very low c-PTP group, 3 (1.4%) in the low c-PTP group, and 1 (3.2%) in the moderate c-PTP group. ConclusionWe provide external validation data of the 4PEPS. In this high-prevalence cohort (26% prevalence), PE prevalence in the very low-risk group was higher than expected. A prospective validation study is needed before implementing the 4PEPS model in routine clinical practice.

Relating D-Dimer, blood sugars, haemoglobin and liver function among COVID patients with T2DM.

It is of interest to evaluate the correlation of D-Dimer, blood sugars, haemoglobin and liver function tests with novel coronavirus in patients with T2DM with and without symptoms. We recruited 200 patients with T2DM and COVID 19 with and without symptoms admitted in Rajarajeshwari Medical College and Hospital, Karnataka. Blood sugars, HbA1c, D-Dimer and also the incidence of T2DM and COVID 19 with and without symptoms were evaluated in all study subjects. There was a significant increased levels of biochemical parameters in T2DM and COVID 19 with symptoms when compared to T2DM and COVID 19 without symptoms (P<0.05). The D-Dimer levels was positively correlated with CT values, (r=0.518, P<0.05). Based on the study findings, the novel coronavirus enhances the insulin resistance, hyper-glycemia, abnormality in the liver and thrombolysis. Additionally, we also suggest that the subjects with T2DM and COVID 19 with and without symptoms require continuous monitoring of D-DIMER and LFT.

D-Dimer and Ultrasonography as the Early-Diagnostic Tools for Lower-Limb Trauma Patients with Deep Vein Thrombosis: A Literature Review

Introduction. The mortality of venous thromboembolism increased among trauma patients. Both the D-dimer test and ultrasonography are selected to diagnose venous thromboembolism due to non-traumatic causes but are rarely utilized in emergency trauma settings. Objectives. This literature review comprehensively explains the accuracy of the D-dimer test and ultrasonography for deep vein thrombosis (DVT) diagnosis. This study finding might broaden the diagnostic recommendation for traumatic patients with deep vein thrombosis. Method. This study used articles from four distinct journal databases. Only eight of the 480 articles found during searching proceeded with the screening process. Thus, five articles were included in the review after matching the eligibility criteria. Results. Three articles compared the accuracy of using the D-dimer test and ultrasonography, while others compared the accuracy of conventional ultrasonography to venography or colour duplex ultrasonography. Using three mg/L as the cut-off point, the D-dimer test's pooled sensitivity and specificity were 88,37% and 96,96%. Meanwhile, ultrasonography for DVT resulted in a pooled sensitivity of 59% and specificity of 95%. Conclusion. Using both tools in trauma cases with DVT would give a more accurate diagnosis. A systematic review of this issue would be preferred to support this argument.

Performance verification and clinical application evaluation of D-dimer assay

Objective: To evaluate the clinical application performance of a domestic D-dimer assay reagent (ADX D-dimer). Methods: A total of 546 residual sodium citrate anticoagulated plasma samples (530 of which were used for comparability validation and 16 for sample preparation of other validation components) were selected after the completion of clinical testing at Peking Union Medical College Hospital from Jun 2022 to May 2023. According to the American Clinical Laboratory Standards Institute (CLSI) guidelines, national health industry standards and relevant references, the performance of ADX D-dimer used in Sysmex CS 5100 fully automated coagulation analyzer which included accuracy, precision, linear range, carryover rate, interference resistance capability and reference interval were validated and the agreement compared with two mainstream imported detection reagents (reagent A: Vidas D-dimer reagent; reagent B: Innovance D-dimer detection reagent) was evaluated. The clinical diagnostic efficacy of the ADX D-dimer was evaluated using the ELISA D-dimer (reagent A) test results as criteria. Results: The linear correlation coefficient of the 6-point calibrated absorbance and target value was 0.998, the bias of accuracy met the requirements (-2.8%-8.4%), and the coefficient of variation (CV) of within-run and between-day precision of the two levels were 1.0%-2.7% and 2.7%-4.1%, respectively, which were less than the requirements of the manufacturer's statement and the national health industry standard. The linear range within 0.33-9.69 mg/L FEU was verified and the carryover rate was 0. There was no significant interference with the assay results at bilirubin F≤0.22 g/L, bilirubin C≤0.22 g/L, hemoglobin≤5.5 g/L and celiac≤2 800 FTU. The manufacturer's reference interval≤0.5 mg/L FEU was verified suitable for this laboratory. For 358 samples without suspicious heterophilic antibody whose D-dimer levels range from 0.06 to143.63 mg/L FEU, the correlation between ADX D-dimer and another two assay was good, with r values being 0.968 and 0.975, respectively, the percentage of deviation and relative deviation beyond the 95% confidence interval was 3.4%-4.5% and 5.3%-7.0%. The correlation between ADX D-dimer and ELISA D-dimer was better than that of reagent B in the concentration range of 0.06-1.00 mg/L FEU (r=0.858, 0.134). For 172 samples with heterophilic antibody, the correlation between ADX D-dimer and ELISA D-dimer was still good(r=0.827), with the percentage of deviation and relative deviation being 6.4% (11/172). The diagnostic efficacy was evaluated using 530 samples, and the sensitivity, specificity, positive predictive value, negative predictive value of ADX D-dimer was 97.4%, 77.6%, 91.9%, 91.9%. The area under the curve was 0.976 (95%CI: 0.964-0.987, P<0.001). Conclusion: The ADX D-dimer reagent has superior assay and diagnostic performance, and can meet the needs of clinical laboratories.

Deep vein thrombosis and pulmonary embolism: a prospective, observational study to evaluate diagnostic performance of the Tina-quant D-Dimer Gen.2 assay.

D-Dimer testing is a diagnostic tool for exclusion of deep vein thrombosis (DVT) and pulmonary embolism (PE). This study evaluated the diagnostic performance of the Tina-quant® D-Dimer Gen.2 assay (Roche Diagnostics International Ltd, Rotkreuz, Switzerland) in patients with low/intermediate pre-test probability of DVT/PE using standard, age-, and clinical probability-adjusted cut-offs. In this prospective, observational, multicenter study (July 2017-August 2019), plasma samples were collected from hospital emergency departments and specialist referral centers. DVT/PE was diagnosed under hospital standard procedures and imaging protocols. A standard D-dimer cut-off of 0.5 µg fibrinogen equivalent units (FEU)/ml was combined with the three-level Wells score; cut-offs adjusted for age (age × 0.01 µg FEU/ml for patients >50 years) and clinical probability (1 µg FEU/ml for low probability) were also evaluated. An assay comparison was conducted in a subset of samples using the Tina-quant D-Dimer Gen.2 assay and the previously established routine laboratory assay, STA-Liatest D-Di Plus assay (Stago Deutschland GmbH, Düsseldorf, Germany). 2,897 patients were enrolled; 2,516 completed the study (DVT cohort: 1,741 PE cohort: 775). Clinical assessment plus D-dimer testing using the standard cut-off resulted in 317 (DVT) and 230 (PE) false positives, and zero (DVT) and one (PE) false negatives. Negative predictive value (NPV) was 100.0% (95% confidence interval [CI]: 99.7%-100.0%) and 99.8% (95% CI: 98.8%-100.0%) for DVT and PE, respectively. After age-adjustment, NPV was 99.9% (95% CI: 99.6%-100.0%) and 99.1% (95% CI: 97.8-99.7) for DVT and PE, respectively. False positive rates decreased (>50%) in clinical probability-adjusted analyses vs. primary analysis. In the assay comparison, the performances of the two assays were comparable. The Tina-quant D-Dimer Gen.2 assay and standard D-dimer cut-off level combined with the three-level Wells score accurately identified patients with a very low probability of DVT/PE.

The dos, don'ts, and nuances of thrombophilia testing.

Considerable progress has been made in elucidating genetic and biologic risk factors for venous thromboembolism (VTE). Despite being able to identify heritable defects in a substantial proportion of patients with VTE, testing has not, in general, proven useful in management. Despite efforts to reduce inappropriate testing, it often falls to the hematologist to consult on patients having undergone thrombophilia testing. Through a series of cases, we discuss how D-dimer testing can be helpful in VTE recurrence risk stratification in younger women as well as how to approach patients with persistently elevated D-dimer levels in the absence of thrombosis. While elevated factor VIII coagulant activity levels are a significant risk factor for a first episode of VTE, its biologic basis is not fully understood, and studies have not shown it to be a useful predictor of recurrence. Abnormal results of genetic tests for methylene tetrahydrofolate reductase or plasminogen activator 1 promoter polymorphisms may be encountered, which carry little if any thrombotic risk and should never be ordered. We also discuss protein S deficiency, the most difficult of the hereditary thrombophilias to diagnose due to a wider "normal" range in the general population as compared with protein C, the presence of both free and bound forms in plasma, and the characteristics of the various assays in use. We also present a rare type of protein C deficiency that can be missed by functional assays using an amidolytic rather than a clotting end point.

Assessment of some hematological factors in patients with COVID-19 and vaccinated individuals in Kirkuk city

Abstract Background: The severe acute respiratory syndrome-coronavirus-2 (SARS-COV-2), which is considered to be the main reason of coronavirus disease-2019 (COVID-19), initiates a multisystem inflammatory condition. The COVID-19 progression is thought to be influenced by hematological abnormalities. A complete blood count (CBC) is a repeatedly used, reasonably priced, and promptly performed testing technique that may be helpful in those processes. The predominance of deep vein thrombosis and pulmonary embolism is determined by d-dimer values. Objective: The aim of this study was to assess the hematological factors in patients with COVID-19 and vaccinated individuals in Kirkuk city. Subject and Methods: Samples were taken from 167 participants aged 20 to 45 years, including men and women, from December 2021 to March 2022; these samples were taken randomly from patients with COVID-19 who were hospitalized and nonhospitalized, those who had received vaccine, and a control group (healthy people who do not have diseases). Samples of nasopharyngeal swabs were also collected from outpatients infected with COVID-19, and the infection was verified using real-time polymerase chain reaction (PCR). Also, PCR was done for control group and performed CBC and d-dimer tests for all samples. Results: Concerning to hematological tests, the outcomes have revealed significant results between study groups with WBC (P &lt; 0.0001), RBC (P &lt; 0.0001), lymphocyte (P &lt; 0.0001), granulocyte (P &lt; 0.0001), HB (P &lt; 0.0001), HCT (P &lt; 0.0001), MCH (P &lt; 0.0017), PLT (P &lt; 0.0455), and d-dimer (P &lt; 0.0001). Conclusion: Patients with COVID-19 have a reliable pattern of CBC parameter changes and normal values in the vaccinated individual.

Epidemiological, Clinical and Radiological Profile of Patients Hospitalized for COVID-19 at the Epidemic Treatment Centre of the Fann Hospital, Dakar during the Third and Fourth Waves

Aims: To describe the epidemiological, clinico-biological and radiological aspects of patients hospitalized for COVID-19 infection at the Fann Epidemics Treatment Center (ETC).&#x0D; Methodology: Cross-sectional study in Fann hospital, between July 2021 and March 2022. We included all patients hospitalized for COVID-19 infection on the basis of epidemiological, clinical and CT scanographic evidence associated with a positive RT-PCR or Ag RDT. The data were entered into Excel and analysed using R software. Qualitative variables were expressed as absolute and relative frequencies. Quantitative variables were described by the average accompanied by its standard deviation or the median associated with the extremes according to their distribution.&#x0D; Results: A total of 248 patients were enrolled during the study period. The average age was 61.7 ±15.2 years. Of the 248 patients, 110 were women (44.4%). High blood pressure was the most frequent comorbidity and was found in 89 patients (35.89%), followed by diabetes (21.7%) and obesity (7.26%) respectively. Three quarters (76.6%) of our patients had not been vaccinated against COVID-19. Dyspnoea was the most frequently encountered clinical symptoms (77%). More than a third of patients (39%) had extra-respiratory symptoms. A total of 109 patients underwent d-dimer testing, of whom 80 (73.4%) had levels ≥ 500ng/ml. One hundred and eighty-two patients (73.4%) had undergone thoracic CT or CT angio. And among them, 71.9% had ground-glass lesions, and half (50%) had severe to critical lesions. In our study, 52 patients died, representing a case-fatality rate of 21%.&#x0D; Conclusion: Our study population consisted mainly of elderly subjects, most of whom had not been vaccinated against COVID-19 and had one or more comorbidities, the most representative of which were high blood pressure, diabetes and heart diseases. In this population, the mortality rate of COVID-19 was significant, approximately one in four patients.

Diagnosis and Therapy of Visceral Vein Thrombosis: An Update Based on the Revised AWMF S2k Guideline.

Splanchnic or visceral vein thromboses (VVTs) are atypical thrombotic entities and include thrombosis of the portal vein, hepatic veins (Budd-Chiari syndrome), mesenteric veins, and splenic vein. All VVTs have in common high 30-day mortality up to 20% and it seems to be difficult to diagnose VVT early because of their rarity and their wide spectrum of unspecific symptoms. VVTs are often associated with myeloproliferative neoplasia, thrombophilia, and liver cirrhosis. VVT is primarily diagnosed by sonography and/or computed tomography. In contrast to venous thromboembolism, D-dimer testing is neither established nor helpful. Anticoagulation is the first-line therapy in patients with stable circulation and no evidence of organ complications. Anticoagulation improves significantly recanalization rates and stops the progress of thrombosis. Low-molecular-weight heparin, vitamin K antagonists, as well as direct-acting oral anticoagulants are possible anticoagulants, but it is noteworthy to be aware that all recommendations supporting the off-label use of anticoagulants are based on poor evidence and consist predominantly of case series, observational studies, or studies with small case numbers. When choosing a suitable anticoagulation, the individual risk of bleeding and thrombosis must be weighted very carefully. In cases of bleeding, bowel infarction, or other complications, the optimal therapy should be determined on a case-by-case basis by an experienced multidisciplinary team involving a surgeon. Besides anticoagulation, there are therapeutic options including thrombectomy, balloon angioplasty, stenting, transjugular placement of an intrahepatic portosystemic shunt, liver transplantation, and ischemic bowel resection. This article gives an overview of current diagnostic and therapeutic strategies.

Development and validation of a clinical prediction model for the diagnostic management of acute pulmonary embolism: an individual participant data meta-analysis

Abstract Background/Introduction Risk stratification is used for decisions about imaging in patients with clinically suspected acute pulmonary embolism (PE). Purpose To develop a clinical prediction model that provides an individualized, accurate probability estimate for acute pulmonary embolism (PE) based on readily available clinical items and D-dimer concentrations. Methods An individual participant data meta-analysis was performed based on sixteen studies with data from 28,305 adult patients with clinically suspected PE from various clinical settings. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict PE at baseline or during follow-up of 30-90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value &amp;lt; 0.10. Discrimination (c-statistic with 95% CI and prediction intervals [PI]) and calibration (outcome:expected [O:E] ratio and calibration plot) were evaluated based on internal-external cross-validation. The accuracy of the model was compared to algorithms based on the Wells score and D-dimer testing. Results The final model included age (in years), sex, previous VTE, recent surgery/immobilization, hemoptysis, cancer, clinical signs of DVT, inpatient status, D-dimer (in μg/L), and an interaction term between age and D-dimer. The pooled c-statistic was 0.87 (95%-CI, 0.85-0.89; 95%-PI, 0.77-0.93) and overall calibration was very good (pooled O:E ratio, 0.99; 95% CI, 0.87-1.14; 95% PI, 0.55-1.79). In the lower range of probabilities, the model slightly overestimated VTE probability. Discrimination of the current model in the validation data sets was better than that of the Wells score combined with a D-dimer threshold based on age (c- statistic 0.73; 95%-CI, 0.70-0.75) or structured clinical pretest probability (c-statistic 0.79; 95%-CI, 0.76- 0.81). Conclusion(s) The present model provides an absolute, individualized probability of PE presence in a broad population of patients with suspected PE, with very good discrimination and calibration. Its clinical utility needs to be evaluated in a prospective management or impact study.Calibration plot of the new model

Soluble ST2 in acute pulmonary embolism

Abstract Purpose ST2 is a member of the IL-1 superfamily. It consists of two components, ST2L, which is the membrane form, and sST2, which is soluble in blood. Soluble ST2 (sST2) is a cardiovascular injury–related biomarker. sST2 is also secreted in response to myocyte and fibroblast mechanical tension and has prognostic value for heart failure. Moreover, biopsy studies have shown that the alveoli are the main source of serum sST2. The extent to which sST2 is elevated in Acute Pulmonary embolism and whether sST2 can discriminate between high-risk and low-risk patients are unknown. Methods Patients whose diagnosis was confirmed by Pulmonary CT Angiography were included in the study. Except for pulmonary embolism, other diseases causing sST2 elevation were excluded. Echocardiographic pulmonary artery pressure, CBC, creatinine, CRP, sST2, and d-dimer tests were performed on the patients and the control group at the time of admission. Results After pre-assessment, 66 patients were included and 62 in the control group, met the study criteria. sST2 levels were positively correlated with the Pulmonary Embolism Severity Index (PESI). sST2 level was associated with increased mortality and prolonged hospitalization (P&amp;lt;0.05). Moreover, sST2 is a sensitive biomarker as D-dimer and a better prognostic predictor than D-dimer. Conclusions Among patients with diagnosed acute pulmonary embolism sST2 showed the superior overall prognostic performance to D-dimer. sST2 might be a useful marker in predicting high-risk patients for Acute PE in the emergency department.

Predictive value of d-dimer for plaque rupture, thrombus and worse clinical outcomes in acute coronary syndrome from TACTICS registry

Abstract Background Acute coronary syndrome (ACS) mainly occurs by the rupture of lipid plaques with platelet aggregation. D-dimer (DD) is a primary degradation product and circulating marker of fibrinolysis. The use of DD helps to diagnose thrombosis. The serum DD level may indicate a thrombus within coronary artery in patients with ACS. Purpose The present study determined the association of serum DD level on admission with a thrombus within culprit lesion and ACS mechanism assessed by optical coherence tomography (OCT), and clinical outcomes. Methods and Results Tokyo/ Kanagawa/ Chiba/ Shizuoka/ Ibaraki active OCT applications for ACS (TACTICS) registry includes 695 consecutive ACS patients who underwent emergent PCI with OCT guidance. Of those, the information of serum DD level was available in 653 cases. Those patients were divided into two groups according to serum DD level on admission: high DD group(≧0.73 μg/ml, n= 328) and low DD group(＜0.73 μg/ml, n= 325). Comparison of type of plaque morphology and thrombus are shown in Figure. ACS patients with high DD level had poor long-term outcomes. Conclusion High serum DD level was associated with red-thrombus, plaque rupture, and worse prognosis in ACS. The simple test of DD may give us useful information in clinical practice for ACS.

Are the latest point-of-care D-dimer devices ready for use in general practice? A prospective clinical evaluation of five test systems with a capillary blood feature for suspected venous thromboembolism

IntroductionWe evaluated clinical performance of five novel point-of-care (POC) D-dimer devices with a capillary finger stick feature for predicting venous thromboembolism (VTE) in general practice: Exdia TRF Plus (E), AFIAS-1® (A), Standard F200® (S), LumiraDx™ (L) and Hipro AFS/1® (H). Materials and methodsPrimary care patients with a low suspicion of a VTE were asked to consent to (i) draw additional venous blood samples, (ii) perform a capillary POC D-dimer test, (iii) approach their general practitioner afterwards for clinical outcomes. Venous plasma samples were processed on all POC devices and a laboratory-based assay (STA-Liatest®D-Di PLUS assay). Results were compared with clinical outcomes to generate performance characteristics. Capillary and venous blood results were used for a matrix comparison. ResultsVenous plasma samples from 511 participants, of whom 57 had VTE, were used for clinical performance analyses. Areas under Receiving Operating Characteristic Curves ranged from 0.90 (95 % CI: 0.86–0.94) (H) to 0.93 (0.90–0.96) (E). All false-negative rates were below 1.4 % (95 % CI: 0.5 %–3.4 %). Matrix comparison demonstrated correlation coefficients ranging from r = 0.11 (95 % CI: −0.15–0.36) (H) to r = 0.94 (0.90–0.97) (A) with concordance percentages ranging from 71.4 % (applying a D-dimer cutoff of 500 ng/mL) (H) to 100 % (applying an age-dependent D-dimer cutoff) (A). ConclusionsClinical performance of the POC D-dimer devices for predicting a VTE in low-risk patients was comparable to that of a laboratory-based assay. However, our results indicate that the finger stick feature of certain devices should be further improved. (NL71809.028.19.)

Lack of Standardized Coding Limits Accuracy of Electronic Clinical Quality Measure for Pulmonary Embolism Diagnosis

Introduction: ASH Guidelines for diagnosis of pulmonary embolism (PE) start with risk assessment using a pretest probability tool (PTP) followed by D-dimer testing or CT pulmonary angiography (CTPA) depending on risk. We aimed to develop an electronic clinical quality measure (eCQM) to encourage broader use of a validated PTP scoring tool in emergency departments (EDs). The Centers for Medicare &amp; Medicaid Services require reporting of eCQMs which consist of value sets or lists of standardized codes linked to patient data within the electronic health record. We sought to identify a standardized way to identify CTPA and abnormal D-dimer tests using administrative codes (i.e. CPT, LOINC, SNOMEDCT codes) across three institutions. Methods: Value sets identifying CTPA and D-dimers were reviewed from existing eCQMs. Three institutions representing 38 EDs from across the country submitted data from all ED encounters between September 12, 2022 and January 11, 2023. Imaging types were reviewed from each of the CPT codes and LOINC (Logical Observation Identifiers Names and Codes). We determined the number of ED encounters, pre-test probability tool use, and diagnosis of PE using different codes. We calculated sensitivity, specificity, positive and negative predictive value (PPV and NPV, respectively). Results: Over the 4-month study period, 270,214 encounters were identified across 38 EDs. Each institution identified CTPA with site-specific codes (Table 1). The Full CTPA Value Set identified 55% more encounters than the site-specific codes (Full set 15,054/9679 site-specific codes). LOINC code 88322-3 was only used at one site. CPT code 71275 had the best sensitivity and specificity, but still had false positives (PPV 82%) (Table 2). D-dimer values were identified as LOINC code 48065-7 and 91556-1 at Site 1 and 48067-3 at Site 2. SNOMEDCT codes were not used at any site despite being the way other eCQMs identify elevated D-dimer results. Different D-dimer tests with different normal ranges were used at each site. All sites did not have an electronically extractable positive indicator for D-dimer. Conclusion: Due to persistent false positives using CPT Code 71275 for identification of CTPA, using this code would lead to inclusion of patients for whom PTP was not required or recommended. Additionally, coding for an abnormal D-dimer test result are not standardized across institutions. Therefore, administrative codes cannot be used to develop eCQMs whose aim is to evaluate whether CTPA is ordered appropriately based on the PTP risk level and laboratory testing.

Relationship between D-dimer level and severity in COVID-19 cases at Dustira Hospital

Coronavirus Disease-2019 (COVID-19) is an emerging disease with clinical symptoms similar to severe pneumonia. It is caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2). COVID-19 encompasses various degrees of severity, including mild, moderate, severe, and critical. One of the supporting tests used to detect COVID-19 is the D-dimer test. This cross-sectional study aims to investigate the relationship between D-dimer levels and the severity of COVID-19. The study was conducted at Dustira Hospital in West Java, Indonesia, from September 2022 to January 2023. D-dimer examination utilizes the Sysmex CS-2500 instrument, with a reference value of &lt;0.5 mg/L. A sample of 42 patients was selected using the purposive sampling technique. The results revealed that the majority of confirmed COVID-19 cases were female (59.5%), with the highest proportion in the age groups of 41-50 years and 51-60 years (33.3%). Among the patients, 52.4% had moderate severity, and 64.3% had increased D-dimer levels. The average D-dimer levels in patients with moderate, severe, and critical symptoms were 0.97 mg/L, 2.33 mg/L, and 4.35 mg/L, respectively. The data were analyzed using the Kruskal-Wallis test, which indicated a significant difference in D-dimer levels based on the severity of COVID-19 (p=0.0001). Elevated D-dimer levels occur as a result of SARS-CoV-2 infection, which triggers an exaggerated inflammatory response leading to a cytokine storm. This, in turn, causes endothelial cell dysfunction and stimulates an excessive immune response, resulting in immune cells attacking healthy tissue. The severity of symptoms worsens as the D-dimer level increases.

Assessment of coagulation assays on Roche Cobas t711 analyzer: performance and clinical implications.

We performed an analytical assessment of five coagulation tests [i.e. prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, thrombin time (TT) and D-dimer] on the Roche Cobas t711 analyzer and a comparison study with the methodology in use at our laboratory (i.e. Werfen ACL Top 750 analyzer), expanding the analysis to the clinical implications of Cobas t711 implementation. Imprecision studies were performed following the Clinical and Laboratory Standards Institute (CLSI) H57 A:2008 guideline. Linearity of D-dimer and fibrinogen tests was analysed according to the CLSI EP06-A: 2003 recommendations. For method comparison, the results were analyzed using the Bland-Altman plot and Passing-Bablok regression. Imprecision met manufacturer claims for PT, aPTT and TT. D-dimer and fibrinogen tests showed a coefficient of variation (CV)% over manufacturer claims at certain concentration levels. Linearity ranges could not be verified. Comparison study revealed that results are not interchangeable for any test, a lower correlation for aPTT test and lower D-dimer results from Roche Cobas t711. The strength of this study relies on the analysis of the clinical implications of reporting Cobas t711 results compared to those obtained with the methodology in use at our laboratory. Different sensibility to factor deficiency, anticoagulant therapy and interferences might explain lower correlation rates obtained for the aPTT test. Different monoclonal antibodies used for D-dimer determination might explain the lower results obtained with the Cobas t711 analyzer. This aspect needs further studies given the relevance of D-dimer test to exclude thrombotic events and reinforces the need of harmonization in the haemostasis laboratory.

PB1021 Using an Age and Fibrinogen Levels Adjusted D-Dimer Cutoff Significantly Improves the Specificity of D-Dimer Testing for Excluding Pulmonary Embolism

PB1021 Using an Age and Fibrinogen Levels Adjusted D-Dimer Cutoff Significantly Improves the Specificity of D-Dimer Testing for Excluding Pulmonary Embolism