Abstract: Objective　To investigate the diagnostic value of d-dimer levels in acute aortic dissection(AAD). Methods　D-dimer levels, C reaction protein and troponin I were tested in all the emergency patients, including 29 patients with aortic dissection confirmed by double source computed tomographyand/or aortic angiography . 30 acute myocardial infarction(AMI) patients in the same period served as control group. Results　D-dimer levels in the aortic dissection group was higher than acute myocardial infarction(807.52±660.78μg/L vs 232.93±115.20μg/L, P<0.01), but four of twenty nine AAD patients were negative, sensitivity is 86.21%. Five of thirty AMI patients showed a slightly elevation of D-dimer. CRP level elevated in both AAD group and AMI group, and AAD group’s CRP level was higher, but there was no statistical significant. Troponin I usually was negative in AAD group, unless AAD patients combined with coronary disease or dissection extended to coronary artery. Conclusion　D-dimer test is helpful for AAD diagnosis, but a negative D-dimer test result couldn’t exclude acute aortic dissection. Combine with troponin I, D-dimer is useful to differentiate between AAD and AMI. CRP is not usefulness in the differential diagnosis of AAD.

Key words: D-dimer, acute aortic dissection, C-reaction protein, tropinon