Risk of thrombotic complications in influenza versus COVID‐19 hospitalized patients

Abstract

Background Whereas accumulating studies on COVID‐19 patients report high incidences of thrombotic complications, large studies on clinically relevant thrombosis in patients with other respiratory tract infections are lacking. How this high risk in COVID‐19 patients compares to those observed in hospitalized patients with other viral pneumonias such as influenza is unknown. Objectives To assess the incidence of venous and arterial thrombotic complications in hospitalized influenza patients as opposed to that observed in hospitalized COVID‐19 patients. Methods Retrospective cohort study; we used data from Statistics Netherlands (study period: 2018) on thrombotic complications in hospitalized influenza patients. In parallel, we assessed the cumulative incidence of thrombotic complications – adjusted for competing risk of death ‐ in patients with COVID‐19 in three Dutch hospitals (February 24th ‐ April 26th 2020). Results Of the 13.217 hospitalized influenza patients, 437 (3.3%) were diagnosed with thrombotic complications, versus 66 (11%) of the 579 hospitalized COVID‐19 patients. The 30‐day cumulative incidence of any thrombotic complication in influenza was 11% (95%CI 9.4‐12) versus 25% (95%CI 18‐32) in COVID‐19. For venous thrombotic complications (VTE) and arterial thrombotic complications alone, these numbers were respectively 3.6% (95%CI 2.7‐4.6) and 7.5% (95%CI 6.3‐8.8) in influenza versus 23% (95%CI 16‐29) and 4.4% (95%CI 1.9‐8.8) in COVID‐19. Conclusions The incidence of thrombotic complications in hospitalized influenza patients was lower than in hospitalized COVID‐19 patients. This difference was mainly driven by a high risk of VTE complications in the COVID‐19 patients admitted to ICU. Remarkably, influenza patients were more often diagnosed with arterial thrombotic complications.

Prevention of venous thromboembolism and haemostasis monitoring in patients with COVID-19: Updated proposals (April 2021)

“…Among hospitalised ##ward/inward## patients, a meta-analysis reported a pooled incidence of deep vein thrombosis and pulmonary embolism (assessed by screening or clinical diagnosis) of 7.1% (95% CI, 4.8–9.8) [5] . This incidence is higher than in non-COVID viral pneumonia: Elgendy et al reported an incidence of VTE of 1.0% among 455,629 hospitalised patients with a primary diagnosis of non-COVID-19 viral pneumonia [6] ; Stals et al reported a 30-day adjusted cumulative incidence for venous thrombotic complications of 3.6% (95% CI, 2.7–4.6) in influenza versus 23% (95%CI, 16–29) in COVID-19 hospitalised patients [7] .…”

Venous thromboembolism associates with SARS-CoV-2 more than seasonal influenza

“…Our ICU followed well-coordinated protocols in managing respiratory failure, making this more likely an effect of anticoagulation than chance observation. Stals et al reported a similar rate of SARS-CoV-2 infected patients on chronic anticoagulation requiring hospitalization at 13% [6] . They did not comment on whether there was a difference in disease severity.…”

Challenges in the diagnostic approach of suspected pulmonary embolism in COVID-19 patients

“…This may be explained by a more intensive inflammatory state and resultant coagulation activation, combined with complete immobilization and resultant lower limb paralysis during mechanical ventilation, and the frequent use of central venous catheters [40][41][42][43]. Moreover, the incidence of thrombotic complications in COVID-19 patients seems to be higher than reported in ICU patients hospitalized for other diseases including influenza [14,44]. Once the high incidence of thrombotic complications in hospitalized COVID-19 patients was elucidated, the threshold to suspect VTE and foremost PE among clinicians lowered.…”

“…Early studies from Wuhan (China) already reported on coagulation abnormalities and coagulopathy in hospitalized patients with COVID-19 at the beginning of 2019 [6][7][8]. This was followed by studies from Europe and America finding alarmingly high rates of VTE in patients with severe COVID-19 infection treated at Intensive Care Units (ICU) and wards [9][10][11][12][13][14][15]. Incidences in these studies varied, but cumulative inci-dences of nearly 50% were reported in ICU patients and, although lower, between 5% and 10% in COVID-19 patients hospitalized on the general wards [16][17][18].…”