# Odds and associated factors for thrombosis development among Lebanese COVID-19 patients: a case–control retrospective study

## TL;DR

This study examines the risk factors for thrombosis in Lebanese COVID-19 patients and finds that prior thromboembolic events and anti-hypertensive use increase risk, while anticoagulants and being female reduce it.

## Contribution

The study identifies specific risk factors for thrombosis in a Lebanese population with COVID-19, emphasizing the protective role of anticoagulants.

## Key findings

- Patients with prior thromboembolic events had a 9.16 times higher risk of thrombosis.
- Anticoagulant use during hospitalization reduced thrombosis risk by 87%.
- Non-severe COVID-19 cases had a 73% lower risk of thrombosis compared to severe cases.

## Abstract

Thromboembolism is reported to be up to 27% in COVID-19 patients due to SARS-CoV-2 infection. Dysregulated systemic inflammation and various patient traits play a vital role in thrombosis progression.

To assess odds and associated factors for thrombosis development among Lebanese COVID-19 patients.

This was a case–control retrospective study conducted in January–May 2021. Patients infected with COVID-19 and developed thrombosis were classified as cases and patients who were thrombosis-free identified as control. A questionnaire assessed socio-demographics, clinical parameters, and WHO COVID-19 disease severity.

Among 267 patients, 26 (9.7%) developed thrombosis and the majority of thrombosis 34.6% was myocardial infarction, and the least (3.8%) was for catheter-related thrombosis. Results showed that the risk of thrombosis development is higher in patients with previous thromboembolic event (OR = 9.160) and previous intake of anti-hypertensive medications at home (OR = 3.116). However, females (OR = 0.330; CI: 0.118–0.925), intake of anticoagulants during hospital admission (OR = 0.126; CI: 0.053–0.300) and non-severe COVID-19 were at lower thrombosis risk (OR = 0.273). Patients who developed thromboembolic events had longer hospital stay (OR = 0.077).

Patients with COVID-19 and thromboembolism were at higher risk of mortality as compared to patients with COVID-19 but without thromboembolism. The use of anticoagulants significantly reduced the risk for thromboembolism.