title: Meta-analysis of usefulness of d-dimer to diagnose acute aortic dissection.
abstract: Numerous studies have examined whether plasma D-dimer (DD) can be used to identify patients with acute aortic dissection (AAD). These studies have been inconclusive because of their limited sample sizes and the different cut-off values employed. We aimed to conduct a systematic review and meta-analysis to examine the utility of plasma DD as a screening tool for AAD. We systematically searched EMBASE and MEDLINE and hand-searched relevant articles to identify studies investigating plasma DD as a screening tool for AAD. A value of 500 ng/ml was defined as the threshold for a positive plasma DD finding because it is widely used for ruling out pulmonary emboli. Using DerSimonian-Laird random-effects models we pooled data across studies to estimate sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios (LRs). We identified 7 studies involving 298 subjects with AAD and 436 without. When data were pooled across studies, sensitivity (0.97, 95% confidence interval [CI] 0.94 to 0.99) and negative predictive value (0.96, 95% CI 0.93 to 0.98) were high. Specificity (0.56, 95% CI 0.51 to 0.60) and positive predictive value (0.60, 95% CI 0.55 to 0.66) were low. Negative LR showed an excellent discriminative ability (0.06, 95% CI 0.03 to 0.12), whereas positive LR did not (2.43, 95% CI 1.89 to 3.12). In conclusion, our meta-analysis suggests that plasma DD <500 ng/ml is a useful screening tool to identify patients who do not have AAD. Plasma DD may thus be used to identify subjects who are unlikely to benefit from further aortic imaging.
authors.affiliation: Divisions of Cardiology and Clinical Epidemiology, Jewish General Hospital/McGill University, Montreal, Quebec, Canada. avidorit@gmail.com
authors.forename: Avi
authors.initials: A
authors.lastname: Shimony
authors.forename: Kristian B
authors.initials: KB
authors.lastname: Filion
authors.forename: Salvatore
authors.initials: S
authors.lastname: Mottillo
authors.forename: Tara
authors.initials: T
authors.lastname: Dourian
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Eisenberg
mesh_terms: D000208:Acute Disease; D000784:Aortic Dissection / Q000097:blood / Q000175:diagnosis*; D001014:Aortic Aneurysm / Q000097:blood / Q000175:diagnosis*; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D006801:Humans; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D