Use of a new monoclonal antibody-based enzyme immunoassay for soluble fibrin to exclude pulmonary embolism

We prospectively evaluated the diagnostic performance of a new soluble fibr in assay in 303 consecutive patients with suspected pulmonary embolism and examined potentially useful cut-off levels at which this disease can be saf ely excluded. In addition, the diagnostic accuracy was calculated in the su bgroups of in- and outpatients. The ROC curve of the assay in the total stu dy cohort had an area under the curve of 0.69. The cut-off level associated with a sensitivity and negative predictive value of 100% was 20 ng/ml. but the specificity was only 4%. The cut-off level with a sensitivity of 90% w as 30 ng/ml, which corresponded with a specificity and negative predictive value of 27% and 86%, respectively. The diagnostic performance Ir as compar able in the subgroups of in- and outpatients. We conclude that the soluble fibrin assay has a low diagnostic accuracy and seems unsuitable as a screen ing test for the exclusion of pulmonary embolism.