To scan or not to scan - D-dimers and computed tomography pulmonary angiography in the era of COVID-19.

The COVID-19 pandemic has had many ramifications on healthcare delivery and practice. As part of this, utilising biomarkers to risk stratify patients has become increasingly popular. During the COVID-19 pandemic the use of D-dimer has increased due to the evidence of COVID-19 induced thrombo-embolic disease. We evaluated the use of D-dimer on all hospital admissions during the peak of the pandemic and evaluated its sensitivity in diagnosing pulmonary embolic disease (PE). Patients without COVID-19 infection were as likely to have evidence of PE as their COVID-positive counterparts. However, the sensitivity of a D-dimer was higher in COVID-positive patients at a lower D-dimer level (>1,500 μg/L, sensitivity 81%, specificity 70%) than in those without clinical, immunological or radiological evidence of COVID-19 infection (D-dimer >2,000 μg/L, sensitivity 80%, specificity 76%). These data suggest higher D-dimer thresholds should be considered for the exclusion of pulmonary emboli. © Royal College of Physicians 2021. All rights reserved.