title: Plasma fibrin D-dimer and the risk of left atrial thrombus: A systematic review and meta-analysis.
abstract: BACKGROUND
  Plasma fibrin d-dimer has been taken as a marker for thrombus. The aim of this study was to evaluate the relationship between d-dimer (DD) levels and left atrial spontaneous echo contrast (SEC)/left atrial thrombus (LAT).
  
  
  METHODS
  We identified clinical studies by systematic search of MEDLINE and EMBASE databases up to Feb 2016. All observational studies that considered DD as a study factor and trans-esophageal echocardiography (TEE) identified SEC/LAT as an outcome were included. Two reviewers independently selected the studies and extracted the data.
  
  
  RESULTS
  Of the 21 included studies, 16 studies (2652 patients) have compared the mean DD differences between patients with and without an evidence of the presence of SEC/LAT, 9 studies (1667 patients) have estimated the diagnostic value of DD in the presence of LAT, and 11 studies (1856 patients) have available information to calculate a ratio of the presence of LAT among individuals in the top and the bottom third of DD levels. The pooled standardized mean difference (SMD) of DD between patients with and without left atrial SEC and/or LAT was 1.29 [95%CI: 0.51, 2.08], with SMDs of 0.42 [95% CI: 0.08, 0.77] and 2.34 [95% CI: 1.01, 3.68] in SEC/LAT and LAT subgroups, respectively. The combined risk ratio of the presence of LAT among individuals between the top of the distribution of DD levels and that in the bottom third was 3.84 [95% CI: 2.35, 6.28], associating with a mean difference of 0.78 ug/ml (1.10 vs 0.32 ug/ml). The pooled sensitivity, specificity and positive likelihood ratio of DD for LAT were 0.75 [95% CI: 0.65, 0.83], 0.81 [95% CI: 0.59, 0.93] and 4.0 [95% CI: 1.7, 9.9], respectively.
  
  
  CONCLUSIONS
  High plasma fibrin DD was associated with left atrial SEC/LAT, particularly among patients with LAT. DD levels have moderate sensitivity and specificity for diagnosing LAT.
authors.affiliation: Department of Cardiology, the First Affiliated Hospital, Jinan University, Guangzhou, China.
authors.forename: Huaibin
authors.initials: H
authors.lastname: Wan
authors.affiliation: Emergency and Intensive Care Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Wu
authors.affiliation: Emergency and Intensive Care Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Yanmin
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Emergency and Intensive Care Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Department of Cardiology, the First Affiliated Hospital, Jinan University, Guangzhou, China.
authors.forename: Aidong
authors.initials: A
authors.lastname: Zhang
authors.affiliation: Emergency and Intensive Care Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liang
mesh_terms: D001281:Atrial Fibrillation / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*; D015415:Biomarkers / Q000097:blood*; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood* / Q000175:diagnosis / Q000209:etiology*
chemical_list: D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D