D-dimer levels remain elevated in acute aortic dissection after 24 h

Background: D-dimer levels are elevated in patients with acute aortic dissection (AAD). Although D-dimer levels have been used to rule out AAD within 24 h of symptom onset, it is unknown whether they may be used reliably after 24 h but within the acute period. Here, we tested the hypothesis that D-dimer levels remain elevated in AAD patients for at least 10 d after dissection onset. Materials and methods: D-dimer levels were measured in preoperative heparinized plasma samples from 100 patients with confirmed AAD for up to 10 d after onset of dissection. When possible, serial samples were obtained for >= 2 d. D-dimer levels were measured in fibrinogen equivalent units using a BCS XP automated coagulation analyzer, which is approved for citrated samples. Therefore, we first validated our samples by comparing D-dimer levels in heparinized and citrated plasma samples from 29 individuals, including patients with and without aortic disease and healthy donors. Results: The correlation between heparinized and citrated plasma samples was 0.991 (P <= 0.001). At a threshold of 1.6 mu g/mL, the overall sensitivity of the D-dimer assay in AAD patients up to 10 d after onset of dissection was 95.3%. Conclusions: D-dimer levels remained elevated in AAD patients over a 10-d period after dissection onset and may be helpful in ruling out AAD in patients who seek treatment after the first 24 h but within the acute period. Heparinized plasma samples maybe substituted for citrated samples when evaluating D-dimer levels using the BCS XP coagulation analyzer. (C) 2014 Elsevier Inc. All rights reserved.