D-dimer in ruling out acute aortic dissection: a systematic review and prospective cohort study.

AIMS Blood D-dimer testing has been proposed as diagnostic marker with high sensitivity for exclusion of acute aortic dissection (AAD). We performed a systematic review and validated the findings in a prospective patient cohort. METHODS AND RESULTS We searched MEDLINE, EMBASE, CINAHL, and BIOSIS from inception until January 2007 using a combination of search terms for aortic dissection and D-dimer. Study type, type of assay used, predefined cut-off level, result of D-dimer testing, sensitivity, and specificity were abstracted. In 16 identified studies (437 patients), the reported cut-off values ranged from 0.1 to 0.9 microg/mL. D-dimer testing provided high sensitivity (0.97 95% CI 0.94-0.98) and negative likelihood ratio (0.06 95% CI 0.02-0.13). In our cohort of 65 patients (36 male, 55%; median age 59 years, IQR 49-67) with proven AAD, D-dimer levels scattered from 0.24 to 137.88 microg/mL (median 3.47; IQR 1.55-14.49). Mean NPV for the different cut-off levels ranged from 92 % for a cut-off level of 0.9 microg/mL to 100% for a cut-off level of 0.1 microg/mL in our study population. CONCLUSION Current evidence supports a routine measurement of D-dimer in excluding AAD. A D-dimer <0.1 microg/mL will exclude AAD in all cases.