BACKGROUND: Radiological and pathological studies in severe COVID-19 pneumonia (SARS-CoV-2) have demonstrated extensive pulmonary immunovascular thrombosis and infarction . This study investigated whether these focal changes may present with chest pain mimicking PE in ambulant patients .

METHODS: CTPAs from outpatients presenting with chest pain to Leeds Teaching Hospital NHS Trust 1st March to 31st May 2020 (n=146) and 2019 (n=85) were compared . Regions of focal ground glass opacity (GGO), consolidation and/or atelectasis (parenchymal changes) were determined, all scans were scored using British Society for Thoracic Imaging (BSTI) criteria for COVID-19, and the 2020 cohort were offered SARS-CoV-2 antibody testing .

RESULTS: Baseline demographic and clinical data were similar between groups with absence of fever, normal lymphocytes and marginally elevated CRP and D-Dimer values . Evidence of COVID-19 or parenchymal changes were observed in 32.9% (48/146) of cases in 2020 compared to 16.5% (14/85) in 2019 (p=0.007). 11/146 (7.5 %) patients met BSTI criteria for COVID-19 in 2020 compared with 0/14 in 2019 (p=0.008). 3/39 patients tested had detectable COVID-19 antibodies (2 with parenchymal changes and 1 with normal parenchyma) however 0/6 patients whose CTPA met BSTI criteria``likely/suspicious for COVID-19"and attended antibody testing were SARS-CoV-2 antibody positive

CONCLUSIONS : 32.8% ambulatory patients with suspected PE in 2020 had parenchymal changes with 7.5% diagnosed as COVID-19 infection by imaging criteria, despite absence of other COVID-19 symptoms . These findings suggest that localised COVID-19 pneumonitis with immunothrombosis occurs distal to the bronchiolar arteriolar circulation, causing pleural irritation and chest pain without viraemia, accounting for the lack of fever and systemic symptoms.