[The diagnosis of deep venous thromboses of the leg using a new rapid test (SimpliRED)]

Evaluation of sensitivity and specificity of a bed-side test in the diagnosis of deep-vein thrombosis compared to contrast phlebography.

122 patients, referred for phlebography, underwent bedside testing (SimpliRED) for detection of deep vein thrombosis. Contrast phlebography was confirmed immediately afterwards. SimpliRED provides a clearly visible agglutination of the patient's red blood cells in the presence of elevated levels of crosslinked fibrin derivatives (D-dimer) in the sample, being specific for fibrin breakdown.

In 37 (30.3%) patients deep vein thrombosis could be confirmed. An abnormal D-dimer test was found in 35 of the 37 patients with thrombosis (sensitivity: 94.6%). Two patients who had not been identified by agglutinin testing, showed an isolated calf thrombosis in small muscle veins (< 2 cm in diameter) not requiring treatment. 55 of 85 patients without thrombosis in phlebography were stated correctly by SimpliRED (specificity: 64.7%).

All thrombotic disorders in the leg with the need for further treatment were identified correctly. SimpliRED is a very sensitive test with moderate specificity in the diagnosis of deep vein thrombosis. Therefore, further invasive testing is needed only in such patients where the D-dimer test is abnormal. A false positive result of the bed-side test may be non-specific or due to elevated levels of fibrin split products, if the coagulation system is activated in several other conditions.