A prospective evaluation of a quantitative D-dimer assay in the evaluation of acute pulmonary embolism.
OBJECTIVE
A prospective study was designed to determine if a screening quantitative serum D-dimer measurement of 1.0 microg/mL or less precludes pulmonary computed tomographic (CT) angiography in patients with possible acute pulmonary embolism (PE).


METHODS
Over a period of 16 months, every patient seen in the emergency department in whom there was clinical suspicion of PE sufficient to warrant pulmonary CT angiography was also requested to have a quantitative serum D-dimer level measurement taken. All pulmonary CT angiography procedures were performed on a four-slice scanner and every examination was overread by a radiologist who was blinded to the D-dimer assay results. Three-month medical record and telephone follow-up was carried out for all participants who had a serum D-dimer level of 1.0 microg/mL or less to verify no new diagnosis or death from PE.


RESULTS
In this prospective study, 361 consecutive patients who received pulmonary CT angiography had a D-dimer level of 1.0 microg/mL or less. There were 310 patients who had negative pulmonary CT angiography results and 50 patients who had indeterminate CT angiography results. Only one patient had positive pulmonary CT angiography findings. Minimum 3-month follow-up information was available for 349 patients, none of whom reported subsequent PE, including those with indeterminate pulmonary CT angiography results.


CONCLUSIONS
The use of a screening D-dimer measurement of 1.0 microg/mL or less precludes pulmonary CT angiography in patients with possible acute PE. The use of this quantitative D-dimer assay would decrease radiation exposure, contrast medium toxicity, cost, and time for patients seen in the emergency medicine department.
Hirai
Lana K
LK
John A. Burns School of Medicine, Kaiser Foundation Hospital, 3288 Moanalua Road, Honolulu, Hawaii 96819, USA.
Takahashi
Jayme M
JM
Yoon
Hyo-Chun
HC
D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D015415:Biomarkers / Q000097:blood; D004636:Emergency Service, Hospital; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism*; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015995:Prevalence; D011446:Prospective Studies; D011651:Pulmonary Artery / Q000000981:diagnostic imaging*; D011655:Pulmonary Embolism / Q000097:blood* / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000453:epidemiology; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D