title: D-dimer to rule out pulmonary embolism in renal insufficiency.
abstract: BACKGROUND
  D-dimer levels are often elevated in renal insufficiency. The diagnostic accuracy of D-dimer to rule out pulmonary embolism in patients with renal insufficiency is unclear.
  
  
  METHODS
  We evaluated the data of patients presenting to our Emergency Department and receiving computed tomography angiography to rule out pulmonary embolism with measurement of D-dimer and creatinine. Glomerular filtration rate was calculated using the Chronic Kidney Disease Epidemiology Collaboration formula.
  
  
  RESULTS
  There were 1305 patients included; 1067 (82%) had an estimated glomerular filtration rate (eGFR) exceeding 60 mL/min, 209 (16%) 30-60 mL/min, and 29 (2%) <30 mL/min. One hundred fifty-two patients (12%) had D-dimer below 500 μg/L. eGFR (R = -0.1122) correlated significantly with D-dimer (P <.0001). One hundred sixty-nine patients (13%) were found to have pulmonary embolism. Sensitivity of D-dimer for patients with an eGFR >60 mL/min was 96% (confidence interval [CI], 0.93-0.99) and 100% (CI, 100-100) for those with 30-60 mL/min, while specificity decreased significantly with impaired renal function. Area under the curve of the receiver operating characteristic for D-dimer was 0.734 in patients with an eGFR of >60 mL/min, and 0.673 for 30-60 mL/min.
  
  
  CONCLUSIONS
  D-dimer levels were elevated in patients with an eGFR <60 mL/min, but proved to be highly sensitive for the exclusion of pulmonary embolism. However, because almost all patients with impaired renal function had elevated D-dimer irrespective of the presence of pulmonary embolism, studies should be performed to determine renal function-adjusted D-dimer cutoffs.
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Switzerland; Department of Internal Medicine, Inselspital, University Hospital Bern, Switzerland. Electronic address: lindner.gregor@gmail.com.
authors.forename: Gregor
authors.initials: G
authors.lastname: Lindner
authors.affiliation: Department of Respiratory and Critical Care Medicine, Otto Wagner Hospital Vienna and Ludwig Boltzmann Institute for COPD and Respiratory Epidemiology, Vienna, Austria.
authors.forename: Georg-Christian
authors.initials: GC
authors.lastname: Funk
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Switzerland; Department of Internal Medicine, Inselspital, University Hospital Bern, Switzerland.
authors.forename: Carmen A
authors.initials: CA
authors.lastname: Pfortmueller
authors.affiliation: Center for Laboratory Medicine, Inselspital, University Hospital Bern, Switzerland.
authors.forename: Alexander B
authors.initials: AB
authors.lastname: Leichtle
authors.affiliation: Center for Laboratory Medicine, Inselspital, University Hospital Bern, Switzerland.
authors.forename: Georg M
authors.initials: GM
authors.lastname: Fiedler
authors.affiliation: Department of Nephrology, Medical University of Graz, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schwarz
authors.affiliation: Department of Emergency Medicine, Inselspital, University Hospital Bern, Switzerland.
authors.forename: Aristomenis K
authors.initials: AK
authors.lastname: Exadaktylos
authors.affiliation: Department of Diagnostic, Interventional and Pediatric Radiology, Inselspital, University Hospital Bern, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: Puig
mesh_terms: D000368:Aged; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis* / Q000209:etiology; D051437:Renal Insufficiency / Q000150:complications; D012189:Retrospective Studies
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D
keywords: CT angiography; D-dimer; Emergency; Pulmonary embolism; Renal insufficiency