key: cord-1035075-3ybp1gab
authors: Tsakok, M. T.; Qamhawi, Z.; Lumley, S. F.; Xie, C.; Matthews, P.; Gleeson, F.; Benamore, R.
title: COVID-19 CT pulmonary angiogram examinations and reported pulmonary embolism incidence: comparison between peak first wave and early second wave
date: 2021-02-05
journal: Clin Radiol
DOI: 10.1016/j.crad.2021.02.001
sha: 85790588085aa87f86f03652c25f60d65df418dc
doc_id: 1035075
cord_uid: 3ybp1gab

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CORRESPONDENCE COVID-19 CT pulmonary angiogram examinations and reported pulmonary embolism incidence: comparison between peak first wave and early second wave Sir-A hypercoagulable state associated with a high prevalence of thromboembolic disease was reported during the first wave of the COVID-19 UK pandemic, with a 22-37% reported incidence of pulmonary embolism (PE) on computed tomography (CT) pulmonary angiography (CTPA) examinations 1-3 and a 28% incidence of thromboembolism (venous or arterial) in the intensive care unit (ICU) COVID-19 patients in a systematic review 4 . The current British Society of Thoracic Imaging (BSTI) guidelines suggest that CTPA be performed in patients with disproportionate hypoxia or a sudden clinical deterioration, but only if the outcome will influence anticoagulation treatment decisions [5] [6] [7] .

In our ~1,100-bed tertiary referral centre in the UK, we have noticed a substantial The rapid rise of PCR-positive cases is thought to be caused, in part, by the variant of concern (VOC). There has been no interim change in the institutional guidance for performing CTPA, which recommend following the current BSTI guidelines 7 , nor in the criteria determining hospital admission.

We performed a service evaluation of CTPA examinations in adults in our institution performed with "COVID" or "coronavirus" specified in the clinical history, comparing a 35-day period corresponding to the local peak PCR confirmed COVID-19 cases 20/3/20 to 24/4/20 (referred to as the first wave) to a 35-day period early in the second wave 1/12/20 to 5/01/21 (referred to as the second wave) and made comparison with the 35-day period corresponding to the peak PCR confirmed COVID-19 cases at our single institution 20/3/20 to 24/4/20 (referred to as the first wave). The study took place as part of an institutionally improved Trust retrospective service evaluation. Repeat studies in the same patient were excluded, whilst the result closest to the date of the CTPA was used in patients with multiple PCR results.

The number of examinations with "COVID" mentioned in the clinical history, over total positive cases in the same time period at our institution, we term the CTPA burden.

There was no significant difference in patient demographics between the first and second wave. During the first wave, 99 CTPA examinations were performed, three were reported as non-diagnostic or equivocal for PE (Table) . Two hundred and seventy-three CTPA examinations were performed in the second wave, of which nine were non-diagnostic or equivocal for PE. PCR-positive rates were 39% for the first wave cohort and 75% for the second wave cohort, whilst CT features of COVID-19 were reported on 61.6% in the first wave cohort and 87.5% on the second wave cohort. A similar proportion of CTPA requests originated from the emergency department (29% versus 27%) whilst 10% of request originated from the ICU during first wave, these account for only 2% during the second wave. Requests from the respiratory high-dependency unit (HDU) accounted for a greater proportion of requests in the second wave. 

Acute pulmonary embolism and COVID-19

Acute pulmonary embolism in patients with COVID-19 at CT angiography and relationship to d-dimer levels

Pulmonary embolism at CT pulmonary angiography in patients with COVID-19

Incidence of thromboembolism in patients with COVID-19: a systematic review and metaanalysis

British Society of Thoracic Imaging. Rationale for CTPA in Covid-19 patients

A British Society of Thoracic Imaging statement: considerations in designing local imaging diagnostic algorithms for the COVID-19 pandemic