European Heart Journal Advance Access originally published online on March 18, 2008
European Heart Journal 2008 29(9):1207; doi:10.1093/eurheartj/ehn118
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Plasma D-dimer in the diagnosis of acute aortic dissection
Sezione di Chimica Clinica
Dipartimento di Scienze Morfologico-Biomediche
Università degli Studi di Verona
Verona
Italy
Sezione di Endocrinologia e Malattie del Metabolismo
Dipartimento di Scienze Biomediche e Chirurgiche
Università di Verona
Verona
Italy
Servizio di Immunoematologia e Trasfusione
Azienda Ospedaliera di Verona
Verona
Italy
Sezione di Chimica Clinica
Dipartimento di Scienze Morfologico-Biomediche
Università degli Studi di Verona
Verona
Italy
Tel: +39 045 812 4308
Fax: +39 045 820 1889
Email: ulippi{at}tin.it/ giuseppe.lippi{at}univr.it
We read with interest the recent article by Sodeck et al., who concluded that D-dimer testing is a reliable and sensitive diagnostic marker for exclusion of acute aortic dissection (AAD). In particular, an exclusion criterion is suggested, based on D-dimer levels <0.1 µg/mL, where the sensitivity of the test is 100%.1 AAD represents a medical emergency that, despite its rare occurrence, is characterized by severe morbidity and mortality. A timely and accurate diagnosis is the key to achieve a positive outcome. According to the current clinical data, diagnosis is mostly based on a high index of suspicion and diagnostic imaging. Similar to deep vein thrombosis and pulmonary embolism,2 plasma D-dimer has recently been suggested as a valuable rule-out test in the diagnostic work-up of AAD.1,3 In fact, because of the high negative predictive value of a negative result, the role of D-dimer testing in patients admitted to the emergency department with suspected AAD might greatly contribute to the diagnostic reasoning, in that it would allow a rapid and reliable exclusion of AAD and other thrombotic pathologies without performing further invasive and expensive analyses.1–4 However, we are rather surprised to read that the threshold recommended by Sodeck et al. for ruling out AAD is 0.1 µg/mL. Reference studies indicate that plasma D-dimer levels vary markedly among healthy individuals and the suggested inter-quartile distribution ranges from 0.175 to 0.345 µg/ml.5 Using the same analytical technique (STA-Liatest D-dimer assay), Ghanima et al. observed that the exclusion rate for venous thrombo-embolism at a higher cut-off point (0.3 µg/mL) than that suggested by Sodeck et al. is <25%.6 Extrapolating the results from the receiver operating characteristic curve of the above mentioned article, the specificity at the 0.1 µg/mL cut-off is lower than 10%. Although studies on AAD and venous thrombo-embolism patients can not be directly compared, the diagnostic specificity is always influenced by the number of false-positive tests in the patients under evaluation. Regardless of the analytical technique to measure D-dimer, we suspect that adoption of a very low cut-off value, such as 0.1 µg/mL, would not be helpful to exclude from the diagnostic workout of AAD most of, if not all, outpatients referred to the emergency department. Probably, complete standardization of D-dimer results will never be possible, because D-dimer is not a single entity in plasma but a mixture of heterogeneous fibrin degradation products, and different antibody specificities from manufacturers.7 Therefore, a highly specific cut-off must be identified for each D-dimer assay used to rule out AAD, as currently suggested for venous thrombo-embolism.8
References
- Sodeck G, Domanovits H, Schillinger M, Ehrlich MP, Endler G, Herkner H, Laggner A. D-dimer in ruling out acute aortic dissection: a systematic review and prospective cohort study. Eur Heart J (2007) 28:3067–3075.
[Abstract/Free Full Text] - Lippi G, Mengoni A, Manzato F. Plasma D-dimer in the diagnosis of deep vein thrombosis. JAMA (1998) 280:1828–1829.
[Free Full Text] - Weber T, Högler S, Auer J, Berent R, Lassnig E, Kvas E, Eber B. D-dimer in acute aortic dissection. Chest (2003) 123:1375–1378.[CrossRef][Web of Science][Medline]
- Immer FF. Is there a place for D-dimers in acute type A aortic dissection? Heart (2006) 92:727–728.
[Abstract/Free Full Text] - Ghanima W, Abdelnoor M, Mowinckel MC, Sandset PM. The performance of STA-Liatest D-dimer assay in out-patients with suspected pulmonary embolism. Br J Haematol (2006) 132:210–215.[CrossRef][Web of Science][Medline]
- Hughes R, Thomson K, Hopkins R, Weatherall M, Wiltshire C, Wilsher M, Beasley R. Determinants of plasma D-dimer levels in a traveling population. J Thromb Haemost (2005) 3:2445–2448.[CrossRef][Web of Science][Medline]
- Jennings I, Woods TA, Kitchen DP, Kitchen S, Walker ID. Laboratory D-dimer measurement: improved agreement between methods through calibration. Thromb Haemost (2007) 98:1127–1135.[Web of Science][Medline]
- Meijer P, Kluft C. The harmonization of quantitative test results of different D-dimer methods. Semin Vasc Med (2005) 5:321–327.[CrossRef][Medline]
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