D-dimer Assay Results Research Articles

Preoperative prevalence and risk factors of deep-vein thrombosis in Japanese surgical patients with ulcerative colitis: a retrospective investigational study.

The purpose of this study was to clarify the perioperative deep-vein thrombosis (DVT) prevalence and its risk factors in surgical ulcerative colitis (UC) patients by comparing the results with those in surgical colorectal cancer (CRC) patients at a high risk of perioperative venous thrombosis. This retrospective, observational study included patients who underwent surgery for UC or CRC between January 2013 and October 2019. Consecutive surgical patients with a positive D-dimer assay result (≥ 1.0µg/ml) underwent lower-extremity venous ultrasonography. The prevalence and risk factors for preoperative DVT were examined in UC patients. A total of 101 UC patients and 593 CRC patients were deemed eligible. Among the D-dimer positive cases, there were no significant differences between the two groups in the preoperative DVT prevalence (UC: 21.8% vs. CRC: 28.8%, p = 0.151), distal type (18.8% vs. 27.2%, p = 0.086), or proximal type (5.9% vs. 4.2%, p = 0.434). Furthermore, multivariate analyses showed that an older age, overweight status, poor ASA status, and a high preoperative dose of steroid were independent risk factors for preoperative DVT in UC surgical patients. The risk of perioperative thrombosis in UC patients was considered similar to that in CRC, so active thromboprophylaxis should be administered to UC patients while paying attention to bleeding. This study was registered with the Japanese Clinical Trials Registry as UMIN000042004 ( http://www.umin.ac.jp/ctr/index.htm ).

Incidence of and risk factors for preoperative deep venous thrombosis in patients undergoing gastric cancer surgery.

Pulmonary thromboembolism (PE) is one of the life-threatening complications of gastric cancer surgery. D-dimer assay is a safe and rapid tool to exclude the presence of deep venous thrombosis (DVT). In July 2012, we started preoperative DVT screening of patients scheduled for gastric cancer surgery using a combination of D-dimer measurements and lower extremity venous ultrasonography to prevent PE. Between July 2012 and August 2015, 976 consecutive patients underwent gastric cancer surgery with preoperative D-dimer screening. Lower extremity venous ultrasonography was performed in patients with a positive D-dimer assay result (greater than 1.0μg/ml). The incidence of and risk factors for preoperative DVT and the incidence of PE were examined in patients undergoing gastric cancer surgery. Of the 976 patients, 176 (18.0%) showed positive D-dimer assay results, and in 13 (1.3%) DVT was diagnosed by lower extremity ultrasonography. Our analysis identified neoadjuvant chemotherapy as a risk factor for preoperative detection of DVT in patients undergoing gastric cancer surgery (P=0.021). The incidence of PE was 0.1% (1/976). Preoperative gastric cancer patients receiving neoadjuvant chemotherapy seem to be at higher risk for the development of DVT.

“Role of D-Dimer in One Year Recurrence of Venous Thromboembolism after Completed Anticoagulation Treatment” Following A First Idiopathic Deep Vein Thrombosis

After oral anticoagulant therapy (OAT) withdrawal, the recurrence of risk is greatest in the first year and gradually diminishes, while the increased bleeding risk may offset the benefits of prolonged OAT. the benefits of extending anticoagulation should be balanced against the risk of bleeding . D-dimer assay and measurement of residual thrombosis on ultrasonography, so-called residual vein obstruction (RVO) were proposed to be effec- tive in selecting patients with idiopathic DVT Materials and methods: This single center prospective study was conducted in patients with a first episode of symptomatic proximal DVT, de - tected by compression ultrasonography (CUS), and who received OAT for at least 3 months. Follow-up was extended from Oct. 2011, to Aug. 2013. After enrollment, patients were re-evaluated at 1st, 6th and 12th months of their follow-up. At the first and 30-day visits, venous blood samples were taken for D-dimer test. All enrolled patients without RVT were stopped OAT. At each follow-up visit, we examined patients and inquired about health status, clinical symptoms or signs of recurrent VTE, bleeding, post-throm- botic manifestations, adherence to treatment, and concomitant analgesic or anti-inflammatory therapy. The end point outcomes were VTE recurrence or complete of this survey follow-ups. Results: A total of 68 eligible patients were enrolled. Four patients (two patients need to using long-term oral anticoagulation, and another two patients for lost to their first follow-up) were excluded. D-dimer and CUS at first was normal in 28 patients (44%) while the remaining 36 patients had abnormal D-dimer but normal CUS while both groups were not consuming their anticoagulant. Total follow-up was 52.5 patient-years. Median follow-up was 11 months (95% CI: 6-17 months). A minimum follow-up of 12 months was avail- able in 44 patients (68%). During follow-up, three recurrent events were recorded (4.6% of patients - 95% CI: 3-7%). All Recurrent events were ipsilateral DVT. Among these index cases, all had an abnormal D-dimer at either T0 and/or T1. The recurrence rate was higher in males than in females (8.6% vs. 2.2%) with an abnormal D-dimer at T0 and/or T1 with a multivariate hazard ratio of 2.1 (95% 1.2-7; p=0.04). Patients older than 65 years had a higher rate of events than younger patients (2/ 12: (16%); 95% CI: 4-24% Vs. 1/ 52: (2%); 95% CI: 0.05-3%) and hazard ratio was about 3.8; (95% CI: 1.95-8.4 p= 0.04). Patients with recurrences had higher mean D-dimer at both T0 and T1 when compared with those without recurrences but the difference was significant only for D-dimer at T1. During follow-up, two patients died (3%). Conclusion: In our cohort of DVT patients, the annual risk of recurrence with an abnormal D-dimer, either during or at one month after VKA withdrawal, was 4.6% which is much lower to the annual risk of recurrence in most studies with idiopathic and provoked VTE. The benefits of extending anticoagulation should be balanced against the risk of bleeding. So according to these results of D-Dimer assay before withdrawal of OAT, this test is helpful for OAT withdrawal decision making.

Evaluation of hemostatic and fibrinolytic markers in dogs with ascites attributable to right-sided congestive heart failure

To determine whether dogs with ascites secondary to right-sided congestive heart failure (CHF) have bleeding disorders associated with hypofibrinogenemia and discordant plasma fibrin-fibrinogen degradation products (FDPs) and D-dimer assay results (ie, a circulating concentration of FDPs higher than the reference range and a circulating concentration of D-dimer within the reference range). Retrospective case-control study. 80 client-owned dogs. Dogs with ascites secondary to right-sided CHF (group 1; n = 20), unhealthy dogs without cardiac disease (group 2; 40), and dogs with left-sided CHF (group 3; 20) were included in the study. Urine bile acids-to-creatinine concentration ratios were calculated as a marker of liver function. Differences among groups regarding coagulation profile analysis results and prevalence of discordant FDPs and D-dimer assay results were determined. No significant differences were detected among the 3 groups regarding urine bile acids-to-creatinine concentration ratios. Plasma fibrinogen concentration was significantly lower for group 1 versus groups 2 or 3. Prevalence of discordant FDPs and D-dimer assay results was significantly higher for group 1 versus groups 2 or 3. Eighteen group 1 dogs had discordant FDPs and D-dimer assay results. Ten of these dogs had concurrent hypofibrinogenemia, 2 of which had clinical signs of bleeding. Only 10 dogs in groups 2 or 3 had discordant FDPs and D-dimer assay results; none of these dogs had hypofibrinogenemia or clinical signs of bleeding. Dogs with right-sided CHF and ascites may be at increased risk for primary hyperfibrinogenolysis (ie, hypofibrinogenemia and discordant FDPs and D-dimer assay results).

D-dimer in the diagnostic workup of suspected pulmonary thrombo-embolism at high altitude

BackgroundPulmonary thrombo-embolism (PTE) is relatively common in high altitude areas where radiological diagnostic facilities are usually not available. So this study was undertaken to use the results of D-dimer assay to determine the need for imaging studies in patients suspected of having PTE at high altitude. MethodsA total of 101 patients at an altitude of > 3,000 m suspected of having PTE were evacuated. D-dimer and imaging studies were carried out to confirm the diagnosis. ResultsA total of 101 patients suspected of having PTE underwent D-dimer level estimation and imaging studies for PTE. Sixty-eight of these had negative findings) on D-dimer assay. All these patients with negative findings on D-dimer assay had negative findings on pulmonary imaging studies also. So this test is very sensitive with very high negative predictive value (NPV). Whereas, 17 out of 33 patients positive for D-dimer, had positive findings on imaging studies, indicating a relatively less specific test. ConclusionClinical assessment in combination with D-dimer assay can be used for timely differentiation of PTE from other conditions such as high altitude pulmonary oedema (HAPO) especially at isolated high altitude areas/military posts, so that patients could be evacuated as early as possible by fastest means to save the precious lives and in hospital settings this test identifies patients to whom anticoagulant therapy should not be given or patients who should not be subjected to invasive imaging tests.

Acute pulmonary embolus in the course of cancer

Risk of pulmonary embolism (PE) is relatively high in patients with advanced chronic diseases, particularly with malignancies. Most patients with cancer have blood coagulation test abnormalities indicative of up-regulation of the coagulation cascade, increased platelet activation and aggregation. Pulmonary thromboembolism is common in patients with any cancer and incidence is increased by surgery, chemotherapy, radiotherapy and disease progression. Manifestations range from small asymptomatic to life-threatening central PE with subsequent hypotension and cardiogenic shock. Diagnostic algorithms utilizing various noninvasive tests have been developed to determine the pretest probability of PE results of D-dimer assay, chest radiography ECG and computed tomography. The mortality in untreated PE is high (30%) but appropriate treatment may decrease it to 2–18%. The current recommended treatment for massive pulmonary embolus is either thrombolytic therapy or surgical embolectomy.

A thrombin generation assay may reduce the need for compression ultrasonography for the exclusion of deep venous thrombosis in the elderly

Introduction. The exclusion of deep venous thrombosis (DVT) by pre-test probability (PTP) and D-dimer in the elderly is safe, but has a low specificity. There is increasing interest in the diagnostic role of thrombin generation in patients with thrombosis. We evaluated the value of thrombin generation in the exclusion of DVT, especially in elderly patients. Material and methods. All thrombin generation parameters of the Endogenous Thrombin Potential assay were tested retrospectively in a cohort of 443 patients suspected for DVT. The performance of the assay was calculated as AUC of the ROC curve and association with DVT as odds ratio (OR). The lag time value was combined with results of PTP and Innovance D-dimer assay. Results. All thrombin generation parameters had a low AUC. In the 4th age quartile, the corrected OR of lag time increased to 16 and the AUC of lag time for the combination PTP < 2 and D-dimers ≥ 500 μg/L was 0.96 with a cut-off value of 23.0 sec. The exclusion of DVT in patients ≥ 75 years (n = 30), based on this combination and lag time values ≤ 23.0 sec had a NPV of 100% and a specificity of 96.0% in this subgroup of patients and decreased the number needed to test from 10 to 1.1. Conclusion. Thrombin generation parameters alone are inappropriate for the exclusion of DVT. However, in the elderly, the current algorithm of exclusion of DVT may improve markedly by the addition of the lag time results of the ETP.

Evaluation of a rapid qualitative immuno-chromatography D-dimer assay (Simplify D-dimer) for the exclusion of pulmonary embolism in symptomatic outpatients with a low and intermediate pretest probability. Comparison with two automated quantitative assays

The performance of a rapid qualitative solid-phase immuno-chromatography-based D-dimer assay (Simplify D-dimer) for diagnosing pulmonary embolism (PE) was evaluated in 469 outpatients with a low or intermediate pretest probability. They were referred to the emergency department of a university hospital during a 4-month period. Test results were compared to those of two automated quantitative assays. Simplify D-dimer assay result was positive in all 47 patients in whom the diagnosis of PE was retained and in 219 of the 422 patients without PE (51.2%), leading to a sensitivity of 100% (95%CI, 92.5 to 100%), a specificity of 48.8% (95%CI, 44.0 to 53.6%) and a negative predictive value (NPV) of 100% (95%CI, 98.2 to 100%). These results compared favorably with those of the Vidas D-dimer New assay [sensitivity = 100% (95%CI, 92.5 to 100), specificity = 49.8% (95%CI, 45.0 to 54.6%) and NPV = 100% (95%CI, 98.3 to 100%)] and the STA ®-Liatest ® D-DI assay [sensitivity = 100% (95%CI, 92.5 to 100%), specificity = 48.1% (95%CI, 43.3 to 52.9%) and NPV = 100% (95%CI, 98.2 to 100%)]. The inter-observer (n = 2) variability was very good with 1.7% discordant readings and a kappa coefficient ( K) value = 0.97 (95%CI, 0.93 to 1.00). In conclusion, the Simplify D-dimer assay could be a valuable tool for ruling out PE in out-patients but a specific learning course of those having to work with is required in order to minimize the number of ambiguous reading and to overcome the inter-observer variability.

D-Dimer Assay to Exclude Pulmonary Embolism in High-Risk Oncologic Population: Correlation with CT Pulmonary Angiography in an Urgent Care Setting

To prospectively evaluate (a) the diagnostic performance of D-dimer assay for pulmonary embolism (PE) in an oncologic population by using computed tomographic (CT) pulmonary angiography as the reference standard, (b) the association between PE location and assay sensitivity, and (c) the association between assay results and clinical factors that raise suspicion of PE. This HIPAA-compliant study had institutional review board approval; informed consent was obtained. Five hundred thirty-one consecutive patients were clinically suspected of having PE; 201 were enrolled (72 men, 129 women; median age, 61 years) and underwent CT pulmonary angiography and D-dimer assay. Relevant clinical history, symptoms, and signs were recorded. CT images were interpreted, and the location of emboli was recorded. The negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity, and diagnostic likelihood ratios of the D-dimer assay results were calculated. Forty-three patients (21%) had pulmonary emboli at CT. D-Dimer results were positive in 171 patents (85%). The NPV and sensitivity were 97% and 98%, respectively. The specificity and PPV were 18% and 25%, respectively. No association was shown between clinical history, symptoms, or signs and NPV, PPV, sensitivity, or specificity or between location of PE and sensitivity. D-Dimer results have high NPV and sensitivity for PE in oncologic patients and, if negative, can be used to exclude PE in this population. Combining the assay with clinical symptoms and signs did not substantially change NPV, PPV, sensitivity, or specificity.

A Prospective Evaluation of a Quantitative D-dimer Assay in the Evaluation of Acute Pulmonary Embolism

A prospective study was designed to determine if a screening quantitative serum D-dimer measurement of 1.0 microg/mL or less precludes pulmonary computed tomographic (CT) angiography in patients with possible acute pulmonary embolism (PE). Over a period of 16 months, every patient seen in the emergency department in whom there was clinical suspicion of PE sufficient to warrant pulmonary CT angiography was also requested to have a quantitative serum D-dimer level measurement taken. All pulmonary CT angiography procedures were performed on a four-slice scanner and every examination was overread by a radiologist who was blinded to the D-dimer assay results. Three-month medical record and telephone follow-up was carried out for all participants who had a serum D-dimer level of 1.0 microg/mL or less to verify no new diagnosis or death from PE. In this prospective study, 361 consecutive patients who received pulmonary CT angiography had a D-dimer level of 1.0 microg/mL or less. There were 310 patients who had negative pulmonary CT angiography results and 50 patients who had indeterminate CT angiography results. Only one patient had positive pulmonary CT angiography findings. Minimum 3-month follow-up information was available for 349 patients, none of whom reported subsequent PE, including those with indeterminate pulmonary CT angiography results. The use of a screening D-dimer measurement of 1.0 microg/mL or less precludes pulmonary CT angiography in patients with possible acute PE. The use of this quantitative D-dimer assay would decrease radiation exposure, contrast medium toxicity, cost, and time for patients seen in the emergency medicine department.

Venous thromboembolism: diagnosis and management of pulmonary embolism

Pulmonary embolism (PE) affects 0.5-1 per 1000 people in the general population each year, and is one of the most common preventable causes of death among hospitalised patients. The clinical diagnosis of PE is unreliable and must be confirmed objectively with ventilation perfusion scanning or computed tomography pulmonary angiography. The diagnosis of PE can be reliably excluded, without the need for diagnostic imaging, if the clinical pretest probability for PE is low and the D-dimer assay result is negative. The initial treatment of PE is low-molecular-weight heparin or unfractionated heparin for at least 5 days, followed by warfarin (target international normalised ratio [INR], 2.0-3.0) for at least 3-6 months. Patients with a high clinical pretest probability of PE should commence treatment immediately while awaiting the results of the diagnostic work-up. Thrombolysis is indicated for patients with objectively confirmed PE who are haemodynamically unstable. Percutaneous transcatheter or surgical embolectomy may be life-saving in patients ineligible for, or unresponsive to, thrombolytic therapy. Unresolved issues in the management of venous thromboembolism include the roles of thrombophilia testing, thrombolysis for the treatment of stable PE patients who present with right ventricular dysfunction, and new anticoagulants; and the duration of anticoagulation for first unprovoked venous thromboembolism.

Sensitivity and Specificity of the Semiquantitative Latex Agglutination D-Dimer Assay for the Diagnosis of Acute Pulmonary Embolism as Defined by Computed Tomographic Angiography

To determine the sensitivity and specificity of the semiquantitative latex agglutination plasma fibrin D-dimer assay for the diagnosis of acute pulmonary embolism by using computed tomographic (CT) angiography as the diagnostic reference standard. From January 1, 1998, to June 26, 2000, patients who had both semiquantitative latex agglutination plasma fibrin D-dimer testing and CT angiography for suspected acute pulmonary embolism were selected for the study. A D-dimer value greater than 250 ng/mL was considered positive for thromboembolic disease. Diagnosis of acute pulmonary embolism was based solely on the interpretation of the CT angiogram. The D-dimer assay results were then compared with the CT angiographic diagnoses. Of 946 CT studies, 172 (18%) were positive for acute pulmonary embolism. The D-dimer assay was positive for 612 (65%) of the 946 patients. For acute pulmonary embolism, the D-dimer assay had a sensitivity of 0.83 (95% confidence interval [CI], 0.76-0.88), a specificity of 039 (95% CI, 036-0.43), a negative likelihood ratio of 0.44 (95 % CI, 032-0.62), and a negative predictive value of 0.91 (95% CI, 0.87-0.94). The semiquantitative latex agglutination plasma fibrin D-dimer assay had moderate sensitivity and low specificity for the diagnosis of acute pulmonary embolism. When used alone, the results of this test were insufficient to exclude this serious and potentially fatal disorder. Approximately two thirds of our patients had positive D-dimer assays and required further evaluation to exclude acute pulmonary embolism.

Embolus location affects the sensitivity of a rapid quantitative D-dimer assay in the diagnosis of pulmonary embolism.

D-dimer blood tests have been suggested to rule out pulmonary embolism. Despite evidence of the safety of withholding anticoagulant treatment in patients with suspected pulmonary embolism and a normal D-dimer assay result, clinicians remain reluctant to use a D-dimer assay as a sole diagnostic test. This prospective study in 314 consecutive inpatients and outpatients investigates the relation between the diagnostic accuracy of D-dimer plasma concentration and pulmonary embolus location. Plasma D-dimer levels were measured using a quantitative immunoturbidimetric method. A strict protocol of ventilation-perfusion scintigraphy, pulmonary angiography, and spiral computed tomography was used to arrive at a final diagnosis and to assess the largest pulmonary artery in which embolus was visible. The influence of embolus location on the diagnostic accuracy was evaluated using the Kruskal-Wallis test and receiver operator characteristics (ROC) analysis. There was a strong correlation between plasma D-dimer concentration and embolus location (Kruskal-Wallis, p < 0.001). Thus, the assay showed greater accuracy in excluding segmental or larger emboli (sensitivity = 93%) than subsegmental emboli (sensitivity = 50%). D-dimer concentration and the accuracy of D-dimer assays are clearly dependent on embolus location and smaller, subsegmental emboli may be missed when D-dimer assays are used as a sole test to exclude pulmonary embolism.