Venous thromboembolism in critically ill adult patients with hematologic malignancy: a population-based cohort study

Purpose — The aim of this study was to describe the incidence of venous thromboembolism (VTE) and major bleeding among hospitalized patients with hematologic malignancy, assessing its association with critical illness and other baseline characteristics.

Methods — We conducted a population-based cohort study of hospitalized adults with a new diagnosis of hematologic malignancy in Ontario, Canada, between 2006 and 2017. The primary outcome was VTE (pulmonary embolism or deep venous thrombosis). Secondary outcomes were major bleeding and in-hospital mortality. We compared the incidence of VTE between intensive care unit (ICU) and non-ICU patients and described the association of other baseline characteristics and VTE.

Results — Among 76,803 eligible patients (mean age 67 years [standard deviation, SD, 15]), 20,524 had at least one ICU admission. The incidence of VTE was 3.7% in ICU patients compared to 1.2% in non-ICU patients (odds ratio [OR] 3.08; 95% confidence interval [CI] 2.77–3.42). The incidence of major bleeding was 7.6% and 2.4% (OR 3.33; 95% CI 3.09–3.58), respectively. The association of critical illness and VTE remained significant after adjusting for potential confounders (OR 2.92; 95% CI 2.62–3.25). We observed a higher incidence of VTE among specific subtypes of hematologic malignancy and patients with prior VTE (OR 6.64; 95% CI 5.42–8.14). Admission more than 1 year after diagnosis of hematologic malignancy (OR 0.64; 95% CI 0.56–0.74) and platelet count ≤ 50 × 109/L at the time of hospitalization (OR 0.63; 95% CI 0.48–0.84) were associated with a lower incidence of VTE.

Conclusion — Among patients with hematologic malignancy, critical illness and certain baseline characteristics were associated with a higher incidence of VTE.