Pulmonary embolism in patients with seasonal influenza: a single centre retrospective review

Abstract

<b>Rationale:</b> Recent systematic review of in-hospital incidence of acute pulmonary embolism (PE) in patients with COVID-19 was 14.7%¹ We set out to review the incidence of PE in seasonal influenza patients admitted to hospital. <b>Methodology:</b> Retrospective review of patients admitted with Influenza like illness and a positive viral swab over 15 months (01/01/2017-01/04/2018). Analysis of demographics, incidence of PE and mortality were assessed. <b>Results:</b> Total of 1261 patients were reviewed in hospital during the study period. Influenza A (46%), mean age 68 and 56% were women. D-dimer was tested in 148 patients with mean value of 1289 ng/mL (normal 0-350 ng/ML). Ninety patients were investigated for PE due to worsening dyspnoea, 89 had Computerised tomography pulmonary angiogram (CTPA) and one patient had ventilation perfusion scan (V/Q). Among those 9 patients were diagnosed with acute PE during the hospitalisation, the incidence of 0.71%. Increased risk factors such as malignancy was not noted among the patients with PE. Overall, in-hospital mortality was 18% with increased risk of death in patients with higher age group (78 v 68 p&lt;0.001). There was no observed higher death rate in PE cohort. <b>Conclusion:</b> The annual incidence of venous thromboembolism is around 200-400 per 100000 among the population group over 60 years. Taking into consideration of observed incidence, we conclude that patients with seasonal influenza have a lower&nbsp;risk of thromboembolism compared to patients infected with novel coronavirus. ¹L Roncon, M Zuin, et al. Incidence of acute pulmonary embolism in COVID-19 patients: Systematic review and meta-analysis. European Journal of Internal Medicine, 2020.