POEMs

Patient-Oriented Evidence That Matters

Increasing the d-Dimer Threshold for Patients with Low Clinical Pretest Probability Effectively Rules Out PE

 

Am Fam Physician. 2020 Jul 15;102(2):117-118.

Clinical Question

Can differing thresholds of d-dimer testing be used for patients with a low to moderate clinical pretest probability to rule out pulmonary embolism (PE)?

Bottom Line

The Pulmonary Embolism Graduated d-Dimer strategy increases the number of patients in the emergency department and outpatient setting who have PE ruled out via d-dimer testing, thus decreasing the need for chest imaging. The benefit is mostly seen by ruling out PE in patients with low clinical pretest probability and a d-dimer level of 500 ng per mL to 999 ng per mL. Patients with a moderate clinical pretest probability and a d-dimer level of less than 500 ng per mL can also be ruled out; however, this subset represented only 2% of the study population. (Level of Evidence = 2b)

Synopsis

Clinical pretest probability in conjunction with d-dimer testing can be a useful strategy for ruling out PE. Patients with low clinical pretest probability and a d-dimer value of less than 500 ng per mL are considered to be ruled out for PE. This study investigates whether a higher d-dimer cutoff value of less than 1,000 ng per mL in patients with low clinical pretest probability and the usual cutoff value of less than 500 ng per mL in patients with moderate clinical pretest probability can also effectively rule out PE. The investigators enrolled 2,056 patients primarily from emergency departments and outpatient clinics who had symptoms or signs suggestive of PE. The Wells Clinical Prediction Rule was applied to determine a patient's pretest probability of PE.

Using the Pulmonary Embolism Graduated d-Dimer strategy, patients with a low clinical pretest probability and a d-dimer level of less than 1,000 ng per mL or those with a moderate clinical pretest probability and d-dimer level of less than 500 ng per mL did not undergo further diagnostic testing for PE and did not receive anticoagulant therapy. All other patients underwent computed tomography pulmonary angiography or ventilation-perfusion lung scanning

POEMs (patient-oriented evidence that matters) are provided by Essential Evidence Plus, a point-of-care clinical decision support system published by Wiley-Blackwell. For more information, see http://www.essentialevidenceplus.com. Copyright Wiley-Blackwell. Used with permission.

For definitions of levels of evidence used in POEMs, see http://www.essentialevidenceplus.com/product/ebm_loe.cfm?show=oxford.

To subscribe to a free podcast of these and other POEMs that appear in AFP, search in iTunes for “POEM of the Week” or go to http://goo.gl/3niWXb.

This series is coordinated by Sumi Sexton, MD, editor-in-chief.

A collection of POEMs published in AFP is available at https://www.aafp.org/afp/poems.

 

 

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