Whole blood agglutination D-dimer test for the diagnosis of deep vein thrombosis.

ABSTRACT

Deep vein thrombosis (DVT) is a clinical syndrome the clinical diagnosis of which is unreliable and objective tests often require specialized testing facilities. The authors examined the diagnostic accuracy of the whole blood agglutination D-dimer (SimpliRED) test in this condition. Patients who presented with acute onset of leg swelling were included in the study. Whole blood agglutination D-dimer test was performed upon admission and followed by the gold standard test, contrast venography. Forty three patients had venography proven DVT and proximal occlusion was found in 31 of them. The sensitivity and specificity of the test for DVT were 88.4 per cent and 53 per cent respectively while the positive predictive value (PPV) and the negative predictive value (NPV) were 82.6 per cent and 64.3 per cent. Interestingly, when focusing the diagnosis on proximal DVT, the sensitivity and NPV rose to 100 per cent, whereas, the specificity and PPV remained unchanged (48.3 and 67.4%). In conclusion, whole blood agglutination D-dimer test (SimpliRED) was sensitive but not specific for DVT diagnosis. Moreover, when focusing the diagnosis on proximal DVT, the test had excellent sensitivity and NPV. This test, therefore, can be an effective screening tool for the high embolic risk proximal DVT.