scholarly journals Performance of the Quantitative Latex Immunoturbidimetric D-dimer Assay for the Diagnosis of Acute Pulmonary Embolism at Rafik Hariri University Hospital

2020 ◽  
Vol 7 (3) ◽  
pp. 125-128
Author(s):  
Rida Salman ◽  
Mira Alsheikh ◽  
Rim Ismail

Background and aims: The diagnostic workup for pulmonary embolism (PE) includes D-dimer assay and computed tomographic angiography. Several D-dimer assays have been approved for PE diagnosis with different sensitivity and specificity. We aimed to study the sensitivity and specificity of the quantitative latex agglutination D-dimer assay used in a referral teaching hospital in Lebanon for the diagnosis of acute PE. Methods: Using a retrospective chart review, we studied 300 patients who had D-dimer test at Rafik Hariri University Hospital in the period between January 1, 2012 and December 31, 2013. Accordingly, 93 patients had a CT angiography after being suspected to have acute PE. A statistical table 2*2 was used to compare the results of CT angiography and D-dimer test. Results: Thirteen patients (13.97%) had PE and 60 patients (64.51%) had positive D-dimer test. Quantitative latex agglutination D-dimer assay had a sensitivity of 69%, specificity of 36%, and negative predictive value of 88%. False positive ratio was also 64%. Moreover, the receiver operating characteristic (ROC) curve was obtained with an area under the curve measuring 0.527. Conclusion: Quantitative latex agglutination D-dimer assay has a high negative predictive value; thus, it can exclude a PE diagnosis if it is associated with low clinical pretest probability.

VASA ◽  
2014 ◽  
Vol 43 (6) ◽  
pp. 450-458 ◽  
Author(s):  
Julio Flores ◽  
Ángel García-Avello ◽  
Esther Alonso ◽  
Antonio Ruíz ◽  
Olga Navarrete ◽  
...  

Background: We evaluated the diagnostic efficacy of tissue plasminogen activator (tPA), using an enzyme-linked immunosorbent assay (ELISA) and compared it with an ELISA D-dimer (VIDAS D-dimer) in acute pulmonary embolism (PE). Patients and methods: We studied 127 consecutive outpatients with clinically suspected PE. The diagnosis of PE was based on a clinical probability pretest for PE and a strict protocol of imaging studies. A plasma sample to measure the levels of tPA and D-dimer was obtained at enrollment. Diagnostic accuracy for tPA and D-dimer was determined by the area under the receiver operating characteristic (ROC) curve. Sensitivity, specificity, predictive values, and the diagnostic utility of tPA with a cutoff of 8.5 ng/mL and D-dimer with a cutoff of 500 ng/mL, were calculated for PE diagnosis. Results: PE was confirmed in 41 patients (32 %). Areas under ROC curves were 0.86 for D-dimer and 0.71 for tPA. The sensitivity/negative predictive value for D-dimer using a cutoff of 500 ng/mL, and tPA using a cutoff of 8.5 ng/mL, were 95 % (95 % CI, 88–100 %)/95 % (95 % CI, 88–100 %) and 95 % (95 % CI, 88–100 %)/94 %), respectively. The diagnostic utility to exclude PE was 28.3 % (95 % CI, 21–37 %) for D-dimer and 24.4 % (95 % CI, 17–33 %) for tPA. Conclusions: The tPA with a cutoff of 8.5 ng/mL has a high sensitivity and negative predictive value for exclusion of PE, similar to those observed for the VIDAS D-dimer with a cutoff of 500 ng/mL, although the diagnostic utility was slightly higher for the D-dimer.


1996 ◽  
Vol 76 (04) ◽  
pp. 518-522 ◽  
Author(s):  
A Elias ◽  
I Aptel ◽  
B Huc ◽  
J J Chale ◽  
F Nguyen ◽  
...  

SummaryThe current D-Dimer ELISA methods provide high sensitivity and negative predictive value for the diagnosis of deep vein thrombosis but these methods are not suitable for emergency or for individual determination. We have evaluated the performance of 3 newly available fast D-Dimer assays (Vidas D-Di, BioMerieux; Instant IA D-Di, Stago; Nycocard D-Dimer, Nycomed) in comparison with 3 classic ELISA methods (Stago, Organon, Behring) and a Latex agglutination technique (Stago). One-hundred-and-seventy-one patients suspected of presenting a first episode of deep vein thrombosis were investigated. A deep vein thrombosis was detected in 75 patients (43.8%) by ultrasonic duplex scanning of the lower limbs; in 11 of them the thrombi were distal and very limited in size (<2 cm). We compared the performance of the tests by calculating their sensitivity, specificity, positive and negative predictive value for different cut-off levels and by calculating the area under ROC curves. The concordance of the different methods was evaluated by calculating the kappa coefficient. The performances of the 3 classic ELISA and of the Vidas D-Di were comparable and kappa coefficients indicated a good concordance between the results provided by these assays. Their sensitivity slightly declined for detection of the very small thrombi. Instant IA D-Di had a non-significantly lower sensitivity and negative predictive value than the 4 previous assays; however its performance was excellent for out-patients. As expected, the Latex assay had too low a sensitivity and negative predictive value to be recommended. In our hands, Nycocard D-Dimer also exhibited low sensitivity and negative predictive value, which were significantly improved when the plasma samples were tested by the manufacturer. Thus significant progress has been made, allowing clinical studies to be planned to compare the safety and cost-effectiveness of D-Dimer strategy to those of the conventional methods for the diagnosis of venous thrombosis.


CJEM ◽  
2017 ◽  
Vol 19 (S1) ◽  
pp. S116
Author(s):  
S. Sharif ◽  
C. Kearon ◽  
M. Li ◽  
M. Eventov ◽  
R. Jiang ◽  
...  

Introduction: Diagnosing pulmonary embolism (PE) in the emergency department can be challenging due to non-specific signs and symptoms; this often results in the over-utilization of CT pulmonary angiography (CT-PA). In 2013, the American College of Chest Physicians identified CT-PA as one of the top five avoidable tests. Age-adjusted D-dimer has been shown to decrease CT utilization rates. Recently, clinical-probability adjusted D-dimer has been promoted as an alternative strategy to reduce CT scanning. The aim of this study is to compare the safety and efficacy of the age-adjusted D-dimer rule and the clinical probability-adjusted D-dimer rule in Canadian ED patients tested for PE. Methods: This was a retrospective chart review of ED patients investigated for PE at two hospitals from April 2013 to March 2015 (24 months). Inclusion criteria were the ED physician ordered CT-PA, Ventilation-Perfusion (VQ) scan or D-dimer for investigation of PE. Patients under the age of 18 were excluded. PE was defined as CT/VQ diagnosis of acute PE or acute PE/DVT in 30-day follow-up. Trained researchers extracted anonymized data. The age-adjusted D-dimer and the clinical probability-adjusted D-dimer rules were applied retrospectively. The rate of CT/VQ imaging and the false negative rates were calculated. Results: In total, 1,189 patients were tested for PE. 1,129 patients had a D-dimer test and a Wells score less than 4.0. 364/1,129 (32.3%, 95%CI 29.6-35.0%) would have undergone imaging for PE if the age-adjusted D-dimer rule was used. 1,120 patients had a D-dimer test and a Wells score less than 6.0. 217/1,120 patients (19.4%, 95%CI 17.2-21.2%) would have undergone imaging for PE if the clinical probability-adjusted D-dimer rule was used. The false-negative rate for the age-adjusted D-dimer rule was 0.3% (95%CI 0.1-0.9%). The false-negative rate of the clinical probability-adjusted D-dimer was 1.0% (95%CI 0.5-1.9%). Conclusion: The false-negative rates for both the age-adjusted D-dimer and clinical probability-adjusted D-dimer are low. The clinical probability-adjusted D-dimer results in a 13% absolute reduction in CT scanning compared to age-adjusted D-dimer.


2002 ◽  
Vol 12 (8) ◽  
pp. 1971-1978 ◽  
Author(s):  
Martine Remy-Jardin ◽  
Isabelle Tillie-Leblond ◽  
David Szapiro ◽  
Benoit Ghaye ◽  
Laurent Cotte ◽  
...  

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4000-4000
Author(s):  
Miklos Egyed ◽  
Peter Zadori ◽  
Peter Rajnics ◽  
Csaba Varga ◽  
Anita Horvath ◽  
...  

Abstract The aims of our study were to evaluate a new pulmonary embolism (PE) diagnostic algorythm and applied VTE prophylaxis. Therefore we reviewed and analysed the medical records of 507 patients with suspected PE. The patients were classified as having preventable or nonpreventable PE according to the risk and adequacy of the administered prophylaxis, or noncompliance if the indicated prophylaxis had been refused. 507 multislice computer tomograph angiography (MuCTA) were done (27 unsuccesful) with a susppected diagnosis of PE between oct.2004 and oct. 2006. From the 140 positive patients 106 were regularly controlled by physicians in different hospitals and 87 had to receive prophylaxis according to the recommendation of the ACCP 2004 guidelines. 7% of them refused it (noncompliance). 70% received inadequate prophylaxis, 23% of the patients (nonpreventable) received prophylaxis in accordance with the ACCP 2004 guidelines. Both Medical and surgical patients were in the preventable group. From the 61 preventable cases, the reason for the inadequacyof prophylaxiswas the omission of prophylaxis in 41, inadequate dose of prophylaxis in 9, inadequate lenght in 5, inadequate anticoagulant in 5 cases. MuCTA is a very useful method to diagnose PE. From the 480 evaluable suspected cases 140 patients found be positive (29%). Adherence to the prophylaxis guidelines is frightful, 70% of patients with PE for whom prophylaxis had been indicated, could have been prevented. The incidence of PE is still high despite adequate prophylaxis, which indicates that the guidelinesmay be needed to reevaluate. Quantitative d-dimer and CRP have very good negative predictive value for excluding PE.


1997 ◽  
Vol 77 (02) ◽  
pp. 262-266 ◽  
Author(s):  
M C H Janssen ◽  
A E Heebels ◽  
M de Metz ◽  
H Verbruggen ◽  
H Wollersheim ◽  
...  

SummaryStudies measuring the fibrin degradation product D-Dimer (DD) using enzyme-linked immunosorbent assays (ELISA) in patients with venographically proven deep venous thrombosis (DVT) suggest that it is possible to exclude DVT when DD level is below a certain cut-off level. However, ELISA methods are time-consuming and not available in all laboratories. Different rapid latex-agglutination assays have been investigated, but their sensitivity is considerably lower.In the present study we compared the value of four novel latex DD tests (Tinaquant®, Minutex®, Ortho® and SimpliRed®) and one rapid ELISA (VIDAS®) to a classical ELISA DD assay (Organon Mab Y18®) in 132 patients suspected of DVT.The VIDAS®, a new quantitative automated ELISA, had a sensitivity of 100% and a negative predictive value of 100% for both proximal and distal DVT at a cut-off level of 500 ng/ml. The Tinaquant® assay, a new quantitative latex method, had a sensitivity of 99% and a negative predictive value of 93% for both proximal and distal DVT at a cut-off level of 500 ng/ml. For proximal DVT only, both assays had a sensitivity and negative predictive value of 100%. VIDAS® and Tinaquant® correlated well with ELISA (correlation of r = 0.96 and r = 0.98 respectively). Sensitivities of the semi-quantitative latex assays Minutex®, Ortho® and SimpliRed® were considerably lower (77%, 51 % and 61 % respectively).These results suggest that VIDAS® and Tinaquant® may be used instead of ELISA DD in the exclusion of DVT. Tinaquant® can be performed within 20 min and VIDAS® within 35 min. Both assays might be used as a routine screening test and should be evaluated in large clinical management studies.


2005 ◽  
Vol 94 (07) ◽  
pp. 206-210 ◽  
Author(s):  
Pieter W. Kamphuisen ◽  
Patricia J. W. B. van Mierlo ◽  
Harry R. Büller ◽  
Maaike Söhne

SummaryExcluding or confirming pulmonary embolism remains a diagnostic challenge. In elderly patients pulmonary embolism is associated with substantial co-morbidity and mortality, and many elderly patients with suspected pulmonary embolism are inpatients. The safety and efficacy of the combination of a clinical probability (CDR) and d-dimer test in excluding pulmonary embolism in this group is unclear. We retrospectively analysed data of two prospective studies of consecutive in-and outpatients with suspected pulmonary embolism. The patients were categorized into three age groups: <65 years, 65–75 years and >75 years. The sensitivity, negative predictive value and the proportion of patients with the combination of a non-high CDR score according to Wells (≤ 4) and a normal d-dimer result were calculated for each group. In 747 consecutive patients with suspected pulmonary embolism, sensitivity and negative predictive value of a non-high CDR and a normal d-dimer result in outpatients (n=538) of all age categories (<65 years, 65–75 years and >75 years) were both 100%.These tests were, however, less reliable for inpatients(n=209), irrespective of their age (sensitivity 91% [ CI: 79–98%], negative predictive value 88 % [CI: 74–96%].The proportion of both in-and outpatients >75 years with a non-high CDR and a normal d-dimer concentration was only 14%,whereas this was 22% in patients 65–75 years and 41% among in-and outpatients <65 years, respectively. In elderly outpatients the combination of a non-high CDR and a normal d-dimer result is a safe strategy to rule out pulmonary embolism. However, in inpatients this algorithm is not reliable to safely exclude pulmonary embolism. In addition, the proportion of patients >65 years in which this strategy excludes pulmonary embolism is markedly lower compared to younger patients.


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