SUMMARY BACKGROUND: The role of D-dimer in excluding deep vein thrombosis (DVT) in pregnancy is currently uncertain. We hypothesized that the specificity of sensitive D-dimer assays could be improved without compromising sensitivity by using higher D-dimer cut-off values. OBJECTIVE: To determine the test characteristics of two rapid enzyme-linked immunosorbent assays and three latex agglutination assays in pregnancy. METHOD: We recruited consecutive pregnant women who presented to participating centers with suspected DVT for the study. Symptomatic women were investigated with compression ultrasonography, and received 3 months of clinical follow-up to assess for the presence of venous thrombosis. Plasma samples for D-dimer were collected and frozen at the time of presentation. The median and mean D-dimer values for respective trimesters of pregnancy in patients with and without DVT were calculated. Receiver operating curves (ROCs) were plotted for respective assays to establish the best cut-points. The test characteristics corresponding to standard cut-points and these 'pregnancy' cut-points are presented. RESULTS: The prevalence of DVT in our cohort was 6.6% (95% confidence interval 4.0-10.6%). The mean and median D-dimer values were significantly increased throughout pregnancy. Overall, women with confirmed DVT had higher D-dimer levels than women without DVT (P < 0.0001). Improved specificities (62-79%) were observed with the use of higher cut-points obtained from ROCs for all five assays, and high sensitivities were maintained (80-100%) for DVT diagnosis. CONCLUSION: Using higher cut-points than those used in non-pregnant patients, the specificity of D-dimer assays for the diagnosis of DVT in pregnancy can be improved without compromising sensitivity. Validation in prospective management studies is needed.
SUMMARY BACKGROUND: The role of D-dimer in excluding deep vein thrombosis (DVT) in pregnancy is currently uncertain. We hypothesized that the specificity of sensitive D-dimer assays could be improved without compromising sensitivity by using higher D-dimer cut-off values. OBJECTIVE: To determine the test characteristics of two rapid enzyme-linked immunosorbent assays and three latex agglutination assays in pregnancy. METHOD: We recruited consecutive pregnant women who presented to participating centers with suspected DVT for the study. Symptomatic women were investigated with compression ultrasonography, and received 3 months of clinical follow-up to assess for the presence of venous thrombosis. Plasma samples for D-dimer were collected and frozen at the time of presentation. The median and mean D-dimer values for respective trimesters of pregnancy in patients with and without DVT were calculated. Receiver operating curves (ROCs) were plotted for respective assays to establish the best cut-points. The test characteristics corresponding to standard cut-points and these 'pregnancy' cut-points are presented. RESULTS: The prevalence of DVT in our cohort was 6.6% (95% confidence interval 4.0-10.6%). The mean and median D-dimer values were significantly increased throughout pregnancy. Overall, women with confirmed DVT had higher D-dimer levels than women without DVT (P < 0.0001). Improved specificities (62-79%) were observed with the use of higher cut-points obtained from ROCs for all five assays, and high sensitivities were maintained (80-100%) for DVT diagnosis. CONCLUSION: Using higher cut-points than those used in non-pregnant patients, the specificity of D-dimer assays for the diagnosis of DVT in pregnancy can be improved without compromising sensitivity. Validation in prospective management studies is needed.
Authors: Shannon M Bates; Roman Jaeschke; Scott M Stevens; Steven Goodacre; Philip S Wells; Matthew D Stevenson; Clive Kearon; Holger J Schunemann; Mark Crowther; Stephen G Pauker; Regina Makdissi; Gordon H Guyatt Journal: Chest Date: 2012-02 Impact factor: 9.410
Authors: Wee-Shian Chan; Frederick A Spencer; Agnes Y Y Lee; Sanjeev Chunilal; James D Douketis; Marc Rodger; Jeffrey S Ginsberg Journal: CMAJ Date: 2013-01-14 Impact factor: 8.262
Authors: E Conti; L Zezza; E Ralli; C Comito; L Sada; J Passerini; D Caserta; S Rubattu; C Autore; M Moscarini; M Volpe Journal: J Thromb Thrombolysis Date: 2014-04 Impact factor: 2.300
Authors: Jignesh P Patel; Raj K Patel; Lara N Roberts; Michael S Marsh; Bruce Green; J Graham Davies; Roopen Arya Journal: BMC Pregnancy Childbirth Date: 2014-11-19 Impact factor: 3.007