Evaluation of a New, Rapid, and Quantitative D-Dimer Test in Patients with Suspected Pulmonary Embolism

Abstract

Previous studies have suggested the utility of D-Dimer ELISA assays in eliminating a diagnosis of pulmonary embolism (PE). Our objectives were to evaluate the performance of a new, rapid, quantitative, and automated Liatest D-Dimer Assay in patients with suspected PE. Three hundred eighty-six consecutive patients referred to our institution between March 1992 and December 1996 for clinically suspected PE, with recent clinical signs not exceeding 1 wk, were included in this study. Diagnosis of PE was based on clinical evaluation, radionuclide lung imaging, lower limb examination, and, when required, pulmonary angiography. D-Dimer performances, for both Liatest D-Dimer and standard D-Dimer ELISA (Asserachrom DDi), assays, were assessed at the end of the study. Among the 386 patients tested, 146 (37.8%) were classified as PE-positive. Liatest D-Dimer assay had a 100% sensitivity (95% confidence interval, 97 to 100%) and a negative predictive value of 100% (95% confidence interval, 94 to 100%). A normal result, below the cutoff of 500 ng/ml, occurred in 83 of the 386 (21%) patients. There was a strong agreement between Liatest D-Dimer and Asserachrom DDi analyses. These findings suggest that this rapid, quantitative, and automated D-Dimer assay provides a useful diagnostic tool for the clinician with regard to exclusion of PE.

Comparison of Diagnostic Accuracies in Outpatients and Hospitalized Patients of D-Dimer Testing for the Evaluation of Suspected Pulmonary Embolism

“…Statistical modeling (not shown) suggests that correction for verification bias might narrow the difference between the tests further. Verification bias may, however, explain why the specificities and negative predictive values in our study are somewhat lower than those reported in previous studies (5,12,15,17,38 ). Selective D-dimer testing in only the low clinical probability group could have artificially increased the exclusion rates.…”

“…On the other hand, the high falsepositive rate that has been noted for D-dimer testing may serve only to increase the number of patients evaluated for VTE, leading to increased morbidity and expense of clinical testing (27 ). Recently, several enhanced microlatex agglutination assays have become available commercially, and results of several studies of these assays appear promising (e.g., (12,17,18 ). Our study is one of the few to compare the diagnostic performance of the new Stago microlatex assay with ELISA D-dimer testing for inpatients and outpatients with suspected PE.…”

“…The details of the method have been described previously (17,18 ). The results were reported as mg/L of FEU; values above 4.0 mg/L were initially reported by the instrument as Ͼ4.0 mg/L, but a repeat test with a 1:5 dilution extended the reportable range to 20 mg/L.…”

Reference Intervals and Method Optimization for Variables Reflecting Hypocoagulatory and Hypercoagulatory States in Dogs using the STA Compact® Automated Analyzer

“…The assay was precalibrated and allowed a 1-time testing on an automated analyzer. 37 According to the manufacturer, the linearity of the assay ranged from 0.0 to 4.0 mg/ml. Antithrombin activity was detected based on the inhibition of thrombin using a chromogenic substrate kit.…”

Comparison of ventilation/perfusion scintigraphy and multi-detector computerized tomography in diagnosis of asymptomatic pulmonary embolism after deep vein thrombosis

“…Eğer klinik olasılık düşük ve perfüzyon sintigrafisi de düşük olasılıklı ise pulmoner emboli tanısından uzaklaştırır. Düşük olası-lıklı sintigrafi bulguları ve yüksek olasılıklı klinik birlikte ise veya tam tersi sözkonusu ise tanı diğer yöntemlerle desteklenmelidir [3,15,16].…”