D-dimer as a biomarker for acute aortic dissection: a systematic review and meta-analysis.

To perform a meta-analysis and examine the use of D-dimer levels for diagnosing acute aortic dissection (AAD). Medline, Cochrane, EMBASE, and Google Scholar were searched until April 23, 2014, using the following search terms: biomarker, acute aortic dissection, diagnosis, and D-dimer. Inclusion criteria were diagnosis of acute aortic dissection, D-dimer levels obtained, 2-armed study. Outcome measures were the accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of D-dimer level for the diagnosis of AAD. Sensitivity analysis was performed using the leave-one-out approach. Of 34 articles identified, 5 met the inclusion criteria and were included in the analysis. The age of participants was similar between treatments within studies. The number of AAD patients ranged from 16 to 107 (total = 274), and the number of control group patients ranged from 32 to 206 (total = 469). The pooled sensitivity of D-dimer levels in AAD patients was 94.5% (95% confidence interval [CI] 78.1%-98.8%, P < 0.001), and the specificity was 69.1% (95% CI 43.7%-86.5%, P = 0.136). The pooled area under the receiver-operating characteristic curve for D-dimer levels in AAD patients was 0.916 (95% CI 0.863-0.970, P < 0.001). The direction and magnitude of the combined estimates did not change markedly with the exclusion of individual studies, indicating the meta-analysis had good reliability. D-dimer levels are best used for ruling out AAD in patients with low likelihood of the disease.