Pulmonary Embolism Detection in COVID-19 Patients

Background: A clinically important impact of Coronavirus Disease 2019 (COVID-19) is the increased likelihood of thromboembolism, mainly pulmonary embolism (PE). To screen for these complications a biochemical marker, D-dimer, is usually done. There is a plethora of research validating the use of D-dimer cutoff levels in non-COVID-19 patients, however less so in the COVID-19 population. Aim: To determine the number of suspected COVID patients with D-dimer ≥ 0.5 and PE reported on CTPA. Methods: Non-interventional single-centre retrospective clinical correlational study. Patient cohort was patients admitted with suspected COVID-19 over a 5-week period. N=690. Results: 76.5% of suspected COVID-19 patients were PCR positive. 40% of these patients had a CTPA completed with 19% reported to have a PE. 52% of patients had a D-dimer value ≥ 0.5 10.6% patients had a PE with a D-dimer ≥ 0.5. Conclusion: Nationally, hospitals are adopting existing D-dimer cut off levels to rule out PEs, however this leads to a large proportion of admitted COVID-19 patients having possibly unnecessary computed tomography pulmonary angiogram. This study highlights that majority of patients with D-dimers above the cut off level have negative PEs and contributes to the notion that standard D-dimer cutoffs are insufficiently accurate to be used as a standalone test in diagnosis in the context of an underlying SARS-CoV-2 infection.