Abbott D-dimer assay: analytical performance and diagnostic accuracy in management of venous thromboembolism.

This study aimed to assess analytical characteristics and diagnostic accuracy in management of venous thromboembolism (VTE) in the Emergency Department (ED) of the Abbott D-dimer assay applied on the Alinity c clinical chemistry analyzer (Abbott Laboratories, Chicago, IL) compared to the INNOVANCE D-dimer assay (Siemens Healthineers, Marburg, Germany). Precision was determined at three concentration levels following the CLSI EP15-A3 protocol. Method comparison and diagnostic accuracy were assessed using samples obtained from 85 patients who were referred for diagnostic imaging and D-dimer testing due to clinically suspected VTE. Within-run coefficients of variation (CVs) were 3.0%, 0.5% and 0.5% at D-dimer concentrations of 0.54, 1.42 and 2.68 mg/L FEU, while respective between-run CVs were 2.0%, 3.4% and 2.7%, hence fulfilling the desirable biological variation criteria for imprecision (<12.6%). Passing-Bablok regression analysis yielded a small proportional difference between the two compared assays (y = 1.09 (95% confidence interval (CI): 1.01-1.18) x + 0.09 (95%CI: -0.09 to 0.16)), while Bland-Altman analysis showed significant negative absolute (-0.6 mg/L FEU, 95%CI: -0.9 to -0.3) and relative mean bias (-14.1%, 95%CI: -20.3 to -7.9). Spearman's ρ was 0.979 (95%CI: 0.967-0.986). Inter-assay agreement relative to the cut-off was 92% (kappa coefficient = 0.547 (95%CI: 0.255-0.839)). Diagnostic sensitivity, specificity, positive and negative predictive values of the Abbott assay were 100%, 9.2%, 25.3% and 100%, respectively, compared to the following data for the INNOVANCE assay: 95.0%, 15.4%, 25.7% and 90.9%. Abbott D-dimer assay has shown excellent analytical precision, high comparability with the INNOVANCE D-dimer and high NPV at manufacturer's cut-off.

Discrepancies between two D-dimer assays and impact on clinical decisions; a retrospective analysis of samples tested in community and hospital-based laboratories in Auckland.

AIM: In patients with suspected venous thromboembolism, an elevated D-dimer level provides an important branch-point in the management pathway. This study compared two D-dimer assays, INNOVANCE® DDimer (Innovance) and STA®-Liatest® D-Di Plus (Liatest), to assess potential impact on clinical management. METHOD: Reflecting current practice in Waitemata, Auckland, we compared paired samples from 805 patients referred to hospital following a community D-dimer test. Samples were determined to be positive or negative using a 500µg/L fibrinogen equivalent units (FEU), and age-adjusted cut-offs. RESULTS: In the Innovance assay, 2% of samples had a result <500µg/L FEU. In contrast, by Liatest, 18% were below 500µg/L. This positive bias of Innovance was amplified with use of age-adjusted cut-offs; 23% of samples with an elevated Innovance result showed a normal result by Liatest. On average, the Innovance values were 22% higher than Liatest. Results suggestive of interference from heterophile antibodies were seen in 6% of sample-pairs. CONCLUSION: Innovance D-dimer test yielded higher values than Liatest and experienced interference from suspected heterophile antibodies. Discrepancies in nearly a quarter of patients may be leading to substantial under or over investigation, inefficient use of resources and clinical confusion.

Distinct age-adjusted D-dimer threshold to rule out acute pulmonary embolism in outpatients and inpatients.

INTRODUCTION: The diagnosis of acute pulmonary embolism (PE) is combinations of clinical probability assessments, plasma D-dimer (DD) test results, and/or computed tomographic pulmonary angiography (CTPA). OBJECTIVE: The aim of this study is to explore the appropriate DD cutoff using the immunoturbidimetric method in outpatients and inpatients. METHODS: We retrospectively enrolled 2689 patients with suspected PE between January 2014 and December 2019. All patients underwent clinical probability assessments, DD tests, and CTPA. We investigated the appropriate cutoff level for plasma DD tests in the correlation analysis and receiver operating characteristic (ROC) curves. RESULTS: Among all patients, 1263 were confirmed acute PE. The age-adjusted DD level was determined to be age × 10 µg/L (for patients aged >50 years) in outpatients. This cutoff value resulted in a sensitivity of 96.75% and a specificity of 87.02%, with the area under the curve (AUC) of 0.908 and the number needed to treat (NNT) of 1.18. For inpatients, the age-adjusted cutoff values for the biomarker DD demonstrated poor specificity (13.34%) and NNT (9.88). However, when the DD cutoff was adjusted to 2 × the upper limit of normal (ULN), the sensitivity increased to 93.19%, while the specificity remained at 29.55%, with the AUC of 0.610 and the NNT of 4.76. The optimal DD cut-off value was 3010 µg/L (about 5 × ULN), resulting in a sensitivity of 75.22% and specificity of 61.72%, with the AUC of 0.727 and the NNT of 2.7. CONCLUSION: Using the immunoturbidimetric method to measure DD, an age-adjusted DD cutoff (age × 10 µg/L, if aged >50 years) should be considered for outpatients with suspected PE. For inpatients, increasing the DD cutoff value to at least 2 × ULN yields the best test performance.

Prospective analysis of pre and postoperative laboratory parameters associated with thrombosis in patients with ovarian cancer.

Patients with ovarian cancer have a high risk of developing thrombosis. We aimed to investigate pre and post operative biomarkers associated with thrombosis including deep vein thrombosis and pulmonary thromboembolism in patients treated for ovarian cancer. We collected pre and post operative blood samples from 133 patients undergoing surgery for ovarian cancer between December 2021 and August 2022. The measured parameters were white blood cell count, hemoglobin, platelets, monocytes, serum glucose, CA125, D-dimer, fibrinogen, prothrombin time, activated partial thromboplastin time, fibrinogen degradation products, antithrombin III, protein C, protein S, plasminogen, plasminogen activator inhibitor 1, homocysteine, N-terminal pro-brain natriuretic peptide, interleukin 6, thrombopoietin, soluble P-selectin and granulocyte stimulating factor. Body mass index of patients were collected. Differences between patients who developed thrombosis and those without were compared with Wilcoxon rank-sum test and we analyzed the continuous variables using logistic regression. Twenty-one (15.8%) patients developed thrombosis ranging from 6 to 146 days (median 15 days) after surgery. Pre operative values of homocysteine (p = 0.033) and IL-6 (p = 0.043) were significantly increased and post operative aPTT (p = 0.022) was prolonged and plasminogen (p = 0.041) was decreased in patients with thrombosis. It is important to find novel biomarkers for thrombosis to carefully manage patients who are prone to develop thrombosis despite preventive measures were applied.

D-dimer levels to exclude pulmonary embolism and reduce the need for CT angiography in COVID-19 in an outpatient population.

OBJECTIVES: Emerging results indicate that, in COVID-19, thromboembolic complications contribute to the high mortality and morbidity. Previous research showed that the prevalence of pulmonary embolism (PE) is between 25-50% in COVID-19 patients, however, most of these reports are based on data from patients with severe pneumonia, treated in intensive care units. MATERIALS AND METHODS: We conducted a retrospective, single-center, observational study to estimate the prevalence of PE in COVID-19 patients who underwent CT angiography and to identify the most important predictors. Adult outpatients with COVID-19, who presented at our COVID Outpatient Clinic between 1st and 31st of March in 2021 and underwent CTA examination were included in this study. Multiple linear regression analysis was used to identify predictors of PE in COVID-19 patients. The predictors were: age, gender, disease duration, CT severity index and log-transformed quantitative D-dimer (logQDDIM) value. RESULTS: 843 COVID-19 patients were included into the study. 82.56% (693 patients) of the infected patients had a pulmonary CTA examination and D-dimer levels (mean age: 59.82 years ± 15.66). 7.61% (53 patients) of the patients had PE. 2.02% (14 patients) of the patients had main branch or lobar PE. The multiple regression analysis found that only logQDDIM was a significant predictor. A logQDDIM cut-off value of 0.0169 (1.0171 ug/ml serum D-dimer) predicted PE with 99% sensitivity (p<0.0001, degree-of-freedom = 570, AUC = 0.72). CONCLUSIONS: We demonstrated in a large cohort of COVID-19 patients that a cut-off value of QDDIM of 1ug/ml can exclude pulmonary embolism in an outpatient setting, implicating that QDDIM might potentially supersede CTA as a screening approach in COVID-19 outpatient clinics.

Association of D-dimer to albumin ratio with adverse cardiovascular outcomes in ischaemic heart failure patients with diabetes mellitus: a retrospective cohort study.

OBJECTIVE: To determine the association of D-dimer to albumin ratio (DAR) with major adverse cardiovascular events (MACE) after percutaneous coronary intervention (PCI) in ischaemic heart failure patients with diabetes mellitus. DESIGN: A retrospective observational cohort study. SETTING: Single centre in Beijing, China, conducted at one of the largest cardiology centres in China. PARTICIPANTS: From June 2017 to June 2019, 3707 patients with heart failure and concomitant multiple vessel disease undergoing elective PCI were screened. A total 1021 of patients were enrolled after exclusion and the follow-up period was up to 36 months. PRIMARY AND SECONDARY OUTCOME MEASURES: The MACE was the primary measured outcome. The secondary outcomes were all-cause mortality, non-fatal myocardial infarction and any revascularisation. METHODS: These participants were grouped according to DAR tertiles. The cumulative incidence functions, Cox regression, restricted cubic spline and receiver operating characteristic curves were used to determine the association between DAR and outcomes. The subgroup analysis was also performed. RESULTS: After follow-up, MACE occurred in 404 (39.6%) participants. The cumulative hazards curve manifested significant differences in MACE, all-cause mortality and any revascularisation (log-rank test: all p<0.001). In adjusted models, DAR was an independent risk factor of MACE (tertile 2: HR 1.82, 95% CI 1.37 to 2.42; tertile 3: HR 1.74, 95% CI 1.28 to 2.36) and all-cause mortality (tertile 2: HR 2.04, 95% CI 1.35 to 3.11; tertile 3: HR 1.89, 95% CI 1.20 to 2.98). The optimal cut-off of DAR was 1.2. In the stratified analysis, sex, age, hypertension, hypercholesterolaemia, total revascularisation and any interfered vessel did not affect the independent predictive ability. CONCLUSION: Higher DAR was independently associated with MACE and all-cause mortality after PCI in ischaemic heart failure patients with diabetes mellitus.

D-Dimer Trends Predict Recurrent Stroke in Patients with Cancer-Related Hypercoagulability.

INTRODUCTION: In patients with cancer-associated hypercoagulability (CAH)-related stroke, D-dimer trends after anticoagulant therapy may offer a biomarker of treatment efficacy. The purpose of this study was to clarify the association between D-dimer trends and recurrent stroke after anticoagulant therapy in patients with CAH-related stroke. METHODS: We performed retrospective cohort study of consecutive patients with CAH-related stroke at two stroke centers from 2011 to 2020. The ratio of posttreatment to pretreatment D-dimer levels (post/pre ratio) was used as an indicator of D-dimer trends after anticoagulant therapy. Fine-Gray models were used to evaluate the association between post/pre ratio and recurrent stroke. RESULTS: Among 360 acute ischemic stroke patients with active cancer, 73 patients with CAH-related stroke were included in this study. Recurrent stroke occurred in 13 patients (18%) during a median follow-up time of 28 days (interquartile range, 11-65 days). Multivariate analysis revealed that high post/pre ratio was independently associated with recurrent stroke (per 0.1 increase: hazard ratio 2.20, 95% confidence interval 1.61-3.01, p = 0.012). CONCLUSION: D-dimer levels after anticoagulant therapy were associated with recurrent stroke in CAH-related stroke patients. Patients with neutral trends in high D-dimer levels after anticoagulant therapy were at high risk of recurrent stroke.

Severe acute urticaria is associated with elevated plasma levels of D-dimer.

Evaluation of the disease severity of acute urticaria (AU) is essential for adequate treatment of patients. However, there are no reliable biomarkers for such an evaluation. In our department, we observed patients with severe AU having elevated plasma D-dimer levels. Thus, the objective of this study was to investigate the elevated D-dimer levels in patients with severe AU in more detail. One hundred and thirty-nine hospital patients diagnosed with severe AU were enrolled. Clinical laboratory data were collected from electronic medical records. One hundred and seventeen of the patients presented with elevated plasma D-dimer levels. Compared to the normal group, the elevated group had a significantly higher proportion of patients who were female, younger, febrile, and had a shorter prehospital time (P < 0.05). Univariate regression analysis showed that neutrophil percentage, C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels increased as D-dimer levels increased, while prehospital time showed the opposite trend. Multiple regression analysis was used to estimate the simultaneous effects of CRP and LDH on D-dimer levels. Patients who responded to additional antibiotic treatment had higher levels of D-dimer. The group with highly elevated D-dimer levels required a higher maximum dose of daily glucocorticoids (GCs) to control the symptoms of AU. In conclusion, patients with severe AU might have elevated plasma D-dimer levels, which are positively correlated with CRP and LDH levels. Patients with severe AU with dramatically elevated D-dimer levels might need a higher dose of daily GCs and antibiotics to relieve symptoms. D-dimer may be a reasonable marker to evaluate the severity of AU and guide treatment.

Optimal D-Dimer Cutoff Values for Diagnosing Deep Vein Thrombosis in Patients with Comorbid Malignancies.

BACKGROUND: Patients with malignancy are at high risk of venous thromboembolism, and early diagnosis is important. The Khorana score is known as a risk assessment for cancer-related thrombosis during chemotherapy, but there are still few reports on its diagnostic potential, the optimal D-dimer cutoff values for indications other than chemotherapy and the use of the Khorana score in combination with D-dimers. In this study, we examined the clinical appropriateness of increasing the D-dimer cutoff value. METHODS: We retrospectively studied 208 malignancies out of 556 patients who underwent lower extremity venous ultrasonography at our hospital over a 2-year period from January 2018 to December 2019. The optimal D-dimer cutoff value for predicting deep vein thrombosis (DVT) in patients with malignancy was calculated by the Youden index. The usefulness of the Khorana score alone and the model combining the Khorana score with D-dimer for predicting DVT diagnosis was compared using receiver operating characteristic analysis. RESULTS: Of 208 eligible patients, 59 (28.4%) had confirmed DVT. The optimal D-dimer cutoff value for predicting DVT comorbidity in patients with malignancy was 3.96 µg/mL. When the new D-dimer cutoff value was set at 4.0 µg/mL, the odds ratio (OR) for DVT diagnosis was 4.23 (95% confidence interval (CI) 2.10-8.55, P < 0.001), which was higher than the OR of 1.33 (95% CI: 0.98-1.81, P = 0.064) for the Khorana score. The area under the curve for the Khorana score and D-dimer was 0.714, which was significantly higher than the 0.611 for the Khorana score alone, with the difference being significantly higher at 0.103 (P = 0.004, 95% CI: 0.033-0.173). CONCLUSIONS: The optimal D-dimer cutoff value for the diagnosis of DVT in patients with malignancy was 4.0 µg/mL. It was also suggested that the combination of the Khorana score with the D-dimer level was more accurate in diagnosing DVT than the Khorana score alone.

[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.

D-dimer, Fibrinogen and Tumor Marker Levels in Patients with benign and Malignant Ovarian Tumors.

Limited studies have investigated the differences between the levels of plasma coagulants and tumor markers in ovarian cancer. Therefore, we conducted this study to determine and compare the level of coagulation, fibrinolysis and tumor markers in patients with benign and malignant ovarian tumors. This cross-sectional study was conducted between January 2022 and February 2023 in Imam Hossein Hospital on patients with ovarian mass. Laboratory tests included platelet count, PT, INR, PTT, fibrinogen and D-dimer were sent to the pathology laboratory to be examined by a pathologist. Based on histopathology, patients were divided into benign, borderline and malignant groups. Logistic regression was used for determine predictors of malignancy. Receiver operating characteristics (ROC) curves and their corresponding 95% CI were determined for the predictor value of the full model. From 141 investigated patients, tumor type in 124 (87.94%) patients were benign, in 12 (8.51%) was malignant and in 5 (3.55%) was borderline. D-dimer, Ca-125 and HE4 were significantly higher in the patients with malignant tumor type (P<0.001), whereas AFP was significantly higher in patients with borderline tumor type (P<0.001). With one-unit increase in D-dimer odds of borderline/malignant tumor 0.3% increases (OR=1.003, 95% CI: 1.001, 1.006) and with one-unit increase in Ca-125 odds of borderline/malignant tumor 1% increases (OR=1.01, 95% CI: 1.003, 1.02). We found that plasma fibrinogen, D-dimer and Ca-125 levels are independently associated with malignant ovarian tumors and combined use of these markers has the high discriminant power for distinction of benign and malignant ovarian masses.
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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.

INTRODUCTION: We 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 METHODS: Primary 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. RESULTS: Venous 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). CONCLUSIONS: Clinical 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.).

Increased plasma DR-70 (fibrinogen-fibrin degradation products) concentrations as a diagnostic biomarker in dogs with neoplasms.

BACKGROUND: Tumor biomarkers have used widely in clinical oncology in human medicine. Only a few studies have evaluated the clinical utility of tumor biomarkers for veterinary medicine. A test for fibrinogen and fibrin degradation products (DR-70) has been proposed as an ideal biomarker for tumors in humans. The clinical value of DR-70 for veterinary medicine however has yet to be determined. OBJECTIVES: Investigate the diagnostic value of DR-70 concentrations by comparing them between healthy dogs and dogs with tumors. ANIMALS: Two hundred sixty-three dogs with different types of tumors were included. Sixty healthy dogs also were recruited for comparison. METHODS: The DR-70 concentrations were measured in all recruited individuals by ELISA. Clinical conditions were categorized based on histopathology, cytology, ultrasound examination, radiology, clinical findings, and a combination of these tests. RESULTS: The median concentration of DR-70 was 2.130 ± 0.868 µg/mL in dogs with tumors, which was significantly higher than in healthy dogs (1.202 ± 0.610 µg/mL; P < .0001). With a cut-off of 1.514 µg/mL, the sensitivity and specificity of DR-70 were 84.03% and 78.33%, respectively. The area under curve was 0.883. The DR-70 concentration can be an effective tumor biomarker in veterinary medicine. CONCLUSIONS AND CLINICAL IMPORTANCE: Increased DR-70 concentrations were not affected by tumor type, sex, age, or body weight. However, in dogs with metastatic mast cell tumors and oral malignant melanoma, DR-70 concentrations were significantly increased. Additional studies, including more dogs with nonneoplastic diseases, are needed to further evaluate the usefulness of DR-70 as a tumor biomarker.

Performance of the 4-Level Pulmonary Embolism Clinical Probability Score (4PEPS) in the diagnostic management of pulmonary embolism: An external validation study.

BACKGROUND: The recently published 4-level Pulmonary Embolism Clinical Probability Score (4PEPS) integrates different aspects from currently available diagnostic strategies to further reduce imaging testing in patients with clinically suspected pulmonary embolism (PE). AIM: To externally validate the performance of 4PEPS in an independent cohort. METHODS: In this post-hoc analysis of the prospective diagnostic management YEARS study, the primary outcome measures were discrimination, calibration, efficiency (proportion of imaging tests potentially avoided), and failure rate (venous thromboembolism (VTE) diagnosis at baseline or follow-up in patients with a negative 4PEPS algorithm). Multiple imputation was used for missing 4PEPS items. Based on 4PEPS, PE was considered ruled out in patients with a very low clinical pre-test probability (CPTP) without D-dimer testing, in patients with a low CPTP and D-dimer <1000 µg/L, and in patients with a moderate CPP and D-dimer below the age-adjusted threshold. RESULTS: Of the 3465 patients, 474 (14 %) were diagnosed with VTE at baseline or during 3-month follow-up. Discriminatory performance of the 4PEPS items was good (area under ROC-curve, 0.82; 95%CI, 0.80-0.84) as was calibration. Based on 4PEPS, PE could be considered ruled out without imaging in 58 % (95%CI 57-60) of patients (efficiency), for an overall failure rate of 1.3 % (95%CI 0.86-1.9). CONCLUSION: In this retrospective external validation, 4PEPS appeared to safely rule out PE with a high efficiency. Nevertheless, although not exceeding the failure rate margin by ISTH standards, the observed failure rate in our analysis appeared to be higher than in the original 4PEPS derivation and validation study. This highlights the importance of a prospective outcome study.

Simple demographic, laboratory and chest radiograph variables can identify COVID-19 patients with pulmonary thromboembolism: a retrospective multicentre United Kingdom study.

OBJECTIVES: To (1) identify discriminatory demographic, laboratory and initial CXR findings; (2) explore correlation between D-dimer and radiographic severity scores; and (3) assess accuracy of published D-dimer thresholds to identify pulmonary thromboembolism (PTE) in COVID-19 patients. METHODS: Retrospective study including all COVID-19 patients admitted from 1st to 30th April 2020 meeting inclusion criteria from 25 (blinded) hospitals. Demographics, blood results, CXR and CTPA findings were compared between positive and negative PTE cohorts using uni- and multivariable logistic regression. Published D-dimer cut-offs were applied. RESULTS: 389 patients were included [median age 63; 237 males], of which 26.2% had a PTE. Significant univariable discriminators for PTE were peak D-dimer, sex, neutrophil count at the time of the D-dimer and at admission, abnormal CXR, and CXR zonal severity score. Only neutrophil count at peak D-dimer remained significant for predicting PTE on multivariable analysis (p = 0.008). When compared with the published literature, sensitivity for PTE were lower than those published at all cut-off values, however specificity at different cut-offs was variable. CONCLUSIONS: In this multicentre COVID-19 cohort, univariable admission factors that could indicate pulmonary thromboembolism were male sex, high neutrophil count and abnormal CXR with a greater CXR zonal severity score. The accuracy levels of published D-dimer thresholds were not reproducible in our population. ADVANCES IN KNOWLEDGE: This is a large multicentre study looking at the discriminatory value of simple variables to determine if a patient with COVID-19 has PTE or not, in addition to comparing D-dimer cut off values against published values.

Incidence and risk factors of admission deep venous thrombosis in nonagenarians and centenarians with intertrochanteric fracture: a retrospective study.

PURPOSE: The objective of this study was to identify the risk factors for admission deep venous thrombosis (aDVT) and proximal aDVT in nonagenarians and centenarians with intertrochanteric fracture (IF). METHODS: We collected statistics on nonagenarians and centenarians with IF admitting from January 2010 to October 2022. Patients with aDVT were considered as the aDVT group and those without aDVT as the non-aDVT group. Additionally, we also conducted a subgroup analysis based on the location of aDVT to investigate the predictors of proximal aDVT. The demographics, comorbidities and admission laboratory examinations of patients were computed by univariate analysis, logistic regression analysis, and receiver operating characteristic (ROC) curve analysis. RESULTS: In our study, the rate of aDVT (109 of 318) was 34.3%, and 5.7% (18 of 318) of patients had proximal aDVT. Logistic regression analysis showed that female patients and a high level of D-dimer were risk factors for aDVT. Similarly, hypoproteinemia and a high level of D-dimer were found to be risk factors for proximal aDVT. ROC curve analysis indicated the cut-off values of D-dimer to predict the aDVT and proximal aDVT were 1.28 mg/L and 1.485 mg/L, respectively. CONCLUSIONS: Our findings investigated the risk factors of aDVT and proximal aDVT in nonagenarians and centenarians with IF and identified the cut-off values of D-dimer, helping us assess the risk of aDVT and proximal aDVT to manage early targeted interventions.

Predictors of cancer in patients with acute pulmonary embolism.

BACKGROUND: Acute pulmonary embolism (PE) can occur as a manifestation of an underlying cancer and be of paraneoplastic aetiology. A previously unknown cancer is sometimes diagnosed after the acute PE diagnosis. The identification of a group of patients with elevated probability of having an occult cancer underlying PE was never performed. We aimed to determine predictors of occult cancer in acute PE. Our hypothesis was that the D-dimer levels would be a predictor of cancer. PATIENTS AND METHODS: We retrospectively analysed a cohort of patients hospitalized with acute PE. EXCLUSION CRITERIA: <18 years, venous embolism only of veins other than pulmonary territory or when the embolism was considered chronic, and no image confirmation of acute PE. Patients were grouped according to the timing of cancer diagnosis: 1) known concomitant active cancer, 2) cancer diagnosed during acute PE admission or in the following 2 years and, 3) no known cancer during the 2-year follow-up since PE diagnosis. Predictors of concomitant cancer were determined using a logistic regression analysis. Multivariate models were built. RESULTS: We studied 562 patients; median age was 72 years and 219 (39.0 %) were men. In 223 (39.7 %) of the patients the PE was of central arteries and 61.4 % presented with bilateral PE. PE was considered unprovoked at time of discharge in 47.7 %. Median (interquartile range) D-dimer level was 7.98 (3.30-14.99) µg/mL. A total of 126 (22.4 %) patients were in group 1, 47 in group 2 (cancer diagnosed after the diagnosis of acute PE and up to 2 years) and 389 patients were in group 3. Elevated D-dimer levels were independently associated with already known cancer. D-dimer were independent predictors of future cancer diagnosis: OR = 1.07 ((95 % CI: 1.01-1.14) per each 5 ng/mL increase; for patients with D-dimer >15.0 µg/mL the OR of future cancer was 2.10 (1.05-4.18). If only patients with unprovoked PE upon admission (n = 307) were to be considered results were similar considering D-dimer; anaemia also predicted unknown cancer [OR = 2.13 (1.08-4.16)]. CONCLUSIONS: Patients with D-dimer >15 µg/mL presented a >2-fold higher risk of being diagnosed with a cancer condition in the upcoming 2 years. D-dimer may help clinicians in identifying which patients are at higher risk of occult cancer.

Role of Fibrin Monomer Complex in Coronavirus Disease 2019 for Venous Thromboembolism and the Prognosis.

Objective Venous thromboembolism (VTE) is a common complication of severe coronavirus disease 2019 (COVID-19) and is associated with its prognosis. The fibrin monomer complex (FMC), a marker of thrombin generation, is reportedly useful in diagnosing acute thrombosis. To date, there has been only one report on FMC in COVID-19, and the usefulness of FMC in COVID-19 is unknown. We therefore evaluated the frequency of VTE in non-intensive-care unit COVID-19 patients in Japan and determine the clinical utility of FMC in COVID-19. Methods This was a single-center retrospective study. Laboratory test results and outcomes (thrombosis and severe progression of COVID-19) were obtained via medical record review. We assessed the relationship between FMC and VTE incidence and evaluated the association between elevated FMC levels and severe progression of COVID-19. Patients This study included 247 patients with COVID-19 who were hospitalized between December 2020 and September 2021 and had had their levels of D-dimer and FMC measured. Results Of the 247 included patients, 3 (1.2%) developed VTE. All three had elevated FMC levels on admission; however, the D-dimer level was not elevated in one case on admission. The FMC level was significantly higher in the group with severe COVID-19 progression than in the group without severe progression. A multivariate analysis showed that severe progression was associated with elevated FMC levels (odds ratio, 7.40; 95% confidence interval, 2.63-22.98; p<0.001). Conclusion FMC can be useful for diagnosing VTE in the acute phase of COVID-19. Elevated FMC was found to be associated with severity on admission and severe progression.

Diagnostic value of D-dimer for lower extremity deep venous thrombosis caused by rib fracture: a retrospective study.

OBJECTIVE: This study aimed to investigate the role of D-dimer in the diagnosis of lower extremity deep venous thrombosis (DVT) in patients with rib fractures. METHOD: Retrospective analysis was conducted on the clinical data of 499 patients with rib fractures who were admitted to the Third Hospital of Shijiazhuang between October 2020 and September 2021. These patients were divided into the DVT and the non-DVT groups. D-dimer levels were compared between the two groups at 24, 48, and 72 h after the injury. Receiver operating characteristic curves were utilized to evaluate the diagnostic efficacy of dynamically monitoring changes in D-dimer for DVT. RESULTS: The D-dimer levels in the DVT group were significantly higher than those in the non-DVT group at 24, 48, and 72 h after the injury. The area under the curve values for predicting DVT based on D-dimer level at 24, 48, and 72 h after injury in patients with rib fractures were 0.788, 0.605, and 0.568, respectively. CONCLUSION: Detecting D-dimer levels 24 h after the injury can enhance diagnostic efficacy and sensitivity for DVT, thereby reducing the rate of missed diagnoses, which is of great clinical value.

Diagnostic management of acute pulmonary embolism: a prediction model based on a patient data meta-analysis.

AIMS: Risk stratification is used for decisions regarding need for imaging in patients with clinically suspected acute pulmonary embolism (PE). The aim was to develop a clinical prediction model that provides an individualized, accurate probability estimate for the presence of acute PE in patients with suspected disease based on readily available clinical items and D-dimer concentrations. METHODS AND RESULTS: An individual patient data meta-analysis was performed based on sixteen cross-sectional or prospective studies with data from 28 305 adult patients with clinically suspected PE from various clinical settings, including primary care, emergency care, hospitalized and nursing home patients. A multilevel logistic regression model was built and validated including ten a priori defined objective candidate predictors to predict objectively confirmed PE at baseline or venous thromboembolism (VTE) during follow-up of 30 to 90 days. Multiple imputation was used for missing data. Backward elimination was performed with a P-value <0.10. Discrimination (c-statistic with 95% confidence intervals [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 subsequently compared with algorithms based on the Wells score and D-dimer testing. The final model included age (in years), sex, previous VTE, recent surgery or immobilization, haemoptysis, cancer, clinical signs of deep vein thrombosis, 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). The model slightly overestimated VTE probability in the lower range of estimated probabilities. 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: 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. REGISTRATION: PROSPERO ID 89366.