Incidence of Thromboembolism in COVID-19 Patients in Intensive Care Units: A Retrospective Cohort Analysis

Introduction: Coronavirus disease 2019 (COVID-19) infection was declared a pandemic, causing high mortality and morbidity worldwide. It predisposes patients to both arterial and venous thromboembolism, which causes high mortality, and is one of the most serious complications of the disease. Objective: The aim of this retrospective study was to determine the frequency of thromboembolic events in patients diagnosed with COVID-19 in the intensive care unit (ICU) and to identify the factors causing thromboembolism. Material and methods: The digital records of patients admitted to the adult ICU of Derince Training and Research Hospital, Kocaeli, Turkey, with a diagnosis of COVID-19 between March 13, 2020, and December 31, 2021, were retrospectively reviewed. Results: Data of 484 patients, 248 (51.2%) female and 236 (48.8%) male, aged between 18-98 years were analyzed. The overall, arterial and venous incidence of thromboembolism was 14.8%, 11.3%, and 3.5%, respectively. There was no significant association between COVID-19 variants and the development of thromboembolism. The effect of various patient variables on the development of thromboembolism was evaluated, including cardiovascular disease (p<0.001), age (p=0.003), use of acetylsalicylic acid (ASA) (p<0.001), antiplatelet therapy (p<0. 001), acute physiology and chronic health evaluation (APACHE) II score (p=0.003), D-dimer (p=0.015), fibrinogen (p=0.032), ferritin (p=0.015), prothrombin time (PT) (p=0.015), international normalized ratio (INR) (p=0.012), troponin (p=0.012) values at the ICU admission were found statistically significant. The cut-off values were 2.565 (μg/mL) for D-dimer, 435.51 (mg) for fibrinogen, 633.55 (ml/ng) for ferritin, 1.155 for INR, and 0.085 (ng/mL) for troponin. Conclusion: Although low-molecular-weight heparin (LMWH) is the first choice, it may be appropriate to add ASA and other antiplatelet agents to reduce the risk of thromboembolism in patients with high thromboembolic risk including advanced age, cardiovascular disease, and elevated levels of D-dimer, troponin, ferritin, and fibrinogen.