The plasma D-dimer assay has long been used, in association with clinical prediction scores, to rule out pulmonary embolism (PE) in critically ill patients. However, a new study suggests that it may not be an appropriate test for patients hospitalized with COVID-19.

The study revealed that all hospitalized patients with COVID-19 and evidence of PE on radiographic evaluation had plasma D-dimer levels of 0.05 μg/mL or more, the cutoff for diagnosis.

From a sample of 1541 patients hospitalized with COVID-19 from January 2020 through February 2021 for a suspected PE, investigators compared plasma D-dimer levels with computed tomography pulmonary angiography (CTPA) in 287 patients. A total of 118 patients (41.1%) needed ICU care, and 27 (9.4%) died during hospitalization.

Thirty-seven patients (12.9%) had radiographic evidence of PE, while 250 patients (87.1%) did not. Around 92.3% patients (n = 265) had plasma D-dimer levels of 0.05 μg/mL or more, which included all patients with PE, and 225 out of 250 patients without PE. The study is published online in JAMA Network Open… (Medscape)