Diagnostic value of tests of fibrin metabolism in patients predisposed to pulmonary embolism.

Blood tests for fibrinogen/fibrin degradation products (FDP/fdp) and soluble fibrin complexes (SFC) were performed in 100 patients at high risk for thromboembolism in order to assess the diagnostic value of these determinations in patients suspected to have pulmonary embolism. Tests were positive significantly less often in high-risk patients, and mean values were significantly lower, when compared with patients with established pulmonary embolism (P less than .001). However, no significant differences existed between high-risk patients and patients with deep venous thrombosis of the legs. Positivity rates and mean values were significantly higher in the presence of pulmonary embolism than in patients with deep venous thrombosis alone (P less than .05). Elevated FDP/fdp and SFC values are useful in the diagnosis of pulmonary embolism in high-risk patients; moreover, positive results in a patient with deep venous thrombosis suggests that pulmonary embolism has occurred.