Value of d-dimer testing in acute aortic dissection.

Aortic Dissection To the Editor: We read with great interest the recent review on etiology, diagnosis and management in aortic dissection.1 In their discussion on diagnostic strategies, the authors state that useful biomarkers for aortic dissection are currently absent. We recently reported on 24 patients with acute aortic dissection in whom D-dimer, a degradation product of cross-linked fibrin, was tested as a part of the initial diagnostic strategy.2 We found that, actually, all patients with acute aortic dissection had elevated levels of D-dimer. In contrast, only 31% of control group patients who had chest pain of other origin—most often coronary artery disease—had increased D-dimer concentrations. Our findings might be explained by activation of the extrinsic pathway of the coagulation cascade at the site of vessel (aortic) wall injury by tissue factor.3 Taking the high negative predictive value (100%) of a negative D-dimer test into account, the role of D-dimer testing in suspected aortic dissection might resemble its established role in suspected deep venous thrombosis and pulmonary embolism.4 Thus, we agree with Nienaber and Eagle1 that testing of biomarkers for aortic dissection has low specificity. However, facing the high negative predictive value of elevated D-dimer levels makes laboratory testing a useful tool in the diagnostic strategy of suspected acute aortic dissection.