Evaluation of plasma D-dimer in the diagnosis and in the course of fibrinolytic therapy of deep vein thrombosis and pulmonary embolism.
Blood samples were obtained from patients with deep venous thrombosis (DVT) or pulmonary embolism (PE) after angiographic confirmation as well as during fibrinolytic therapy with streptokinase. Plasma cross-linked fibrin degradation products were measured by a quantitative enzyme-linked immunoassay that recognizes the D-Dimer epitope. 24 patients with PE showed elevated D-Dimer levels (median; 25%-, 75%-quartile) (3,250 ng/ml; 1,270 ng/ml, 6,940 ng/ml) as well as 38 patients presenting with DVT (2,330 ng/ml; 1,760 ng/ml, 3,980 ng/ml). The sensitivity for the diagnosis of PE was 92%, for diagnosis of DVT 89% resp. 100%, depending on the cut-off limit. The D-Dimer level showed a correlation (r = 0.64) to the angiographically documented severity of PE quantified by the Miller's score, in contrast to DVT, where no such correlation could be found. During fibrinolytic therapy median levels rose from 3,020 ng/ml to 63,000 ng/ml within 8 hours and then fell within 6 days to 2,930 ng/ml. 10 patients with PE showed a good correlation (r = 0.72) between the reduction of Miller's score within 72 hours and D-Dimer 24 hours after the onset of therapy. In 17 patients with fibrinolytic treatment of DVT no correlation between D-Dimer and clot lysis could be found. These findings indicate that D-Dimer can provide additional information in the diagnostic procedure of suspected PE. During fibrinolytic therapy of PE with streptokinase, D-Dimer could serve as an early prognostic parameter of successful thrombolysis.