title: D-dimer testing for safe exclusion and risk stratification in patients with acute pulmonary embolism in primary care.
abstract: BACKGROUND
  Safe exclusion and risk stratification are currently recommended for the initial management of patients with acute pulmonary embolism (APE). The aim of this study was to assess the safe exclusion and risk stratification value of D-dimer (DD) for APE when tested at the beginning of admission.
  
  
  METHODS
  All consecutive Chinese APE patients and controls were recruited from January 2010 to December 2012. All measurements of serum indexes were made in duplicate and blinded to the patients' status. All the 40 patients with the first episode of APE were confirmed by multi-detector computed tomographic pulmonary angiography. The plasma prothrombin time (PT), activated partial thromboplastin time, thrombin time, fibrinogen, and DD levels were measured within 24 h of admission. We used the Mann-Whitney U-test to determine the differences between groups and drew receiver operator characteristic curve to evaluate the indexes' value in the APE screening.
  
  
  RESULTS
  The PT and DD in the APE group were significantly higher than those in the disease control group (P < 0.05). Taking PT and DD as the useful screening tests for APE and AUC was 0.765 and 0.822, respectively. DD yielded the higher screening efficiency, with DD >1820 μg/L as cut-off value, the sensitivity, specificity, positive and negative predictive value was 82.5%, 75.2%, 56.9%, and 91.6%, respectively.
  
  
  CONCLUSIONS
  The patients with APE showed significant higher DD levels compared with disease controls, suggesting a negative qualitative DD test result can safely and efficiently exclude APE in primary care.
authors.affiliation: Department of Laboratory Medicine, The Second Affiliated Hospital of Zhejiang Chinese Medical University, Hangzhou, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yin
authors.affiliation: Department of Clinical Laboratory and Hospital Management Office, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Clinical Laboratory and Hospital Management Office, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Xie
authors.affiliation: Department of Clinical Laboratory and Hospital Management Office, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
authors.forename: Zhexin
authors.initials: Z
authors.lastname: Shao
keywords: Acute pulmonary embolism; D-dimer; coagulation indicators; risk stratification