The Importance of Clinical Probability Assessment in Interpreting a Normal d-Dimer in Patients With Suspected Pulmonary Embolism

Computed tomography pulmonary angiography as a single imaging test to rule out pulmonary embolism

“…A meta-analysis including all high-quality prospective studies investigating the safety of ruling out pulmonary embolism based on a normal D-dimer blood test result, and an unlikely clinical probability according to the Wells rule, confirmed this very low risk in 1660 consecutive patients with a pooled negative predictive value of 99.7% (95% CI 99.0-99.9) and a very low pulmonary embolismrelated mortality risk of 0.06% (95% CI 0.0017-0.46) [20]. In contrast, patients with a likely clinical probability should undergo further testing regardless of the D-dimer test outcome as venous thromboembolism can be diagnosed in 9.3% (95% CI 4.8-17.3%) of the patients with a negative D-dimer test result in this population [21]. In addition to the Wells rule, several alternative clinical decision rules are available to assess the pretest probability of having pulmonary embolism (Table 1, [19][20][21][22][23][24][25]).…”

Validity and clinical utility of the simplified Wells rule for assessing clinical probability for the exclusion of pulmonary embolism

“…As a result this assay had a negative predictive value of 100% for excluding clinically significant PE. This might seem optimistic considering the fact that there are several studies that indicated that it was not safe to manage patients on the D-dimer test result alone; in patients in whom PE is likely further diagnostic testing is usually advocated (16)(17)(18)(19). However, the observed negative predictive value of 100% has no impact on our analysis, since this uncertainty is reflected by the 95% CI of the three-month thromboembolic risk (i.e.…”

Use of imaging for investigation of suspected pulmonary embolism during pregnancy and the postpartum period

“…The measurement of D-dimer is controversial and recommendations are confusing. 7,12,15,16 An important caveat is that negative D-dimer in the setting of a low clinical probability 8,23 has excellent negative predictive value, and as mentioned above, pregnant women are by definition not low risk, as highlighted by a recent case report 24 of a pregnant woman with multiple PEs and serially negative D-dimer. One concerning aspect of the use of D-dimer in pregnancy is that the elevation may be interpreted as suggestive of venous thromboembolism (VTE), rather than a normal finding in pregnancy, thus D-dimer has not only a very low yield for the exclusion of VTE but potential to increase the rates of imaging.…”