OC 05.3 - Incidence and Risk Factors for Venous Thromboembolism in Hospitalized Patients Across Three Major COVID-19 Variants in an Asian Cohort

Saturday, June 24, 2023

13:30 – 13:45 ET

Room: 511

Session Available As: On-Demand

Presenting Author(s)

Shir Ying Lee, MBBS, MRCP, FRCPath

Senior Consultant
Division of Haematology, Department of Laboratory Medicine, National University Hospital, Singapore
Singapore, Singapore

Co-Author(s)

WT

Winnie ZY Teo

Consultant
Fast Medicine, Alexandra Hospital, Singapore
Singapore, Singapore
CL

Cheryl XQ Lim

Associate Consultant
Division of Haematology, Department of Laboratory Medicine, National University Hospital, Singapore
Singapore, Singapore
WJ

Wei Ying Jen

Consultant
Department of Haematology-Oncology, National University Hospital, Singapore
Singapore, Singapore
CL

Chun Tsu Lee

Consultant
Fast Medicine, Alexandra Hospital, Singapore
Singapore, Singapore
EY

Eng Soo Yap

Doctor
Department of Haematology-Oncology, National University Health System, Singapore
Singapore, Singapore
YC

Yen Lin Chee

Senior Consultant
Department of Haematology-Oncology, National University Hospital, Singapore
Singapore, Singapore

Background: The incidence of venous thromboembolism (VTE) in COVID-19 is high, especially in intensive care unit (ICU) patients. Asians have a lower risk of VTE relative to Caucasians and extrapolation of thromboprophylaxis guidelines based on Caucasian data may not be appropriate. However, there is limited data on VTE in Asians with COVID-19.

Aims: Determine the hospitalized incidence of VTE in Asians with COVID-19, VTE trend and risk factors in successive COVID-19 waves (wildtype, delta and omicron).

Methods: Retrospective cohort study of hospitalized COVID-19 adults from January 2020 to February 2022. Objectively confirmed VTE were reviewed to obtain overall VTE rates and trends during each COVID-19 wave. Subset analysis of critical (ICU), moderate (oxygen, no ICU) and mild cases hospitalized ≥ 5 days to investigate risk factors and in-hospital VTE hazard.

Results: 1444 wildtype, 1229 delta and 901 omicron patients were identified. The number of VTE events were 5 (0.35%), 7 (0.57%) and 4 (0.44%) respectively (Table 1). Moderate and critical infections were highest for delta. On multivariate analysis, only age and severity of infection remained independent predictors. Relative risk (95% confidence interval) was 0.96 (0.93–0.99) per year age increase, 8.31 (2.20–31.43) for critical and 6.73 (1.58–28.63) for moderate versus mild infection. The maximum hazard of VTE for mild infection was 1.16% at 14 days, moderate infection was 10.56% at 21 days and critical infection was 13.98% at 35 days (Figure 1).

Conclusion(s): The overall VTE rate in Asians with COVID-19 is very low ( < 1%). Severity of infection rather than variant type, and younger age independently increase the risk of VTE. A low incidence of VTE in mild COVID-19 was seen despite the low thromboprophylaxis rate. The in-hospital VTE hazard is greatest with critical infection despite high thromboprophylaxis rate. Patients with moderate infections are likely to derive the best risk-benefit balance with standard dose thromboprophylaxis.

Learning Objectives:

Describe the in-hospital incidence and hazard rate of venous thromboembolism in Asian patients with COVID-19 infection.
Compare the rates of venous thromboembolism across different degrees of infection severity and three major COVID-19 waves.
Compare the incidence of venous thromboembolism in an Asian COVID-19 cohort with that of historical cohorts from other countries.