The high frequency of residual radiologic abnormalities after initial deep vein thrombosis (DVT) makes management of patients with suspected recurrence difficult. D-dimer (DD) and serial compression ultrasonography (CUS) of the proximal veins have a high sensitivity and negative predictive value (NPV) in suspected first DVT. We hypothesized that it would be safe to withhold anticoagulation in patients with suspected recurrence who had a negative sensitive DD or negative serial CUS when DD testing was positive. In a multicentre prospective cohort study, patients underwent DD testing with an immunoturbidometric assay (MDA DD). If the DD was negative (<0.5 ug fibrinogen equivalent units [FEU]/mL), patients had no further testing. If the DD was positive, CUS was performed and, if normal, repeated after 1–3 and 7–10 days. Patients with a positive DD and abnormal CUS at presentation were managed as per their treating physician. Patients were followed for 3 months to detect venous thromboembolism (VTE) and suspected VTE were adjudicated centrally. Of the 504 patients enrolled in this study, 14 were subsequently deemed ineligible and 2 patients were lost to follow-up. The overall prevalence of confirmed recurrent DVT at presentation or during follow-up was 17%. 230 patients had a negative DD at presentation and, of the 227 evaluable patients, 4 had definite confirmed VTE (NPV of DD = 98%; 95% Confidence Interval [CI], 96–99%). Of the 135 patients with a positive DD and normal initial CUS, serial CUS was negative in 129 cases. Of these patients, 3 had definite VTE during follow-up (NPV of serial CUS in patients with positive DD = 98%; 95% CI, 93–99%). These results suggest that a negative MDA DD result excludes clinically significant recurrent DVT and that anticoagulants can also be safely withheld in patients with negative serial CUS, even if their DD is positive. This simple diagnostic approach can be used to safely manage approximately 70% of patients with suspected recurrent DVT.
Disclosure: Consultancy: Dr. Bates - consultancy with bioMerieux and Trinity Biotech (manufacturers of the MDA D-Dimer). Research Funding: MDA D-Dimer kits supplied by manufacturer (Organon Teknika Corp; bioMerieux, Inc; Trinity Biotech).