Tests of fibrin metabolism in recurrent venous thromboembolism.

Fibrinogen/fibrin degradation products (FDP/fdp) and soluble fibrin complexes (SFC) were measured serially in 60 patients heparinized for pulmonary embolism or deep venous thrombosis. Eight patients had recurrent thromboembolism. In patients without recurrence, FDP/fdp and SFC tended to normalize within three to five days. In patients with recurrence, results of both tests were significantly higher on admission, and FDP/fdp values were significantly higher throughout ten days of therapy, than in patients without recurrence. The SFC values were not different between the two groups during the first six days of treatment, but again became significantly higher on the seventh day in patients with recurrence. There were no differences in clotting times, heparin dosage, or any other clinical features between patients with and without recurrence. Measurement of FDP/fdp and SFC can help identify patients at risk of recurrent thromboembolism if performed serially during treatment.