Risk of Venous Thromboembolism in Hospitalized Patients with Chronic Lymphocytic Leukemia Complicated with Autoimmune Hemolytic Anemia

Introduction: Autoimmune hemolytic anemia is a recognized complication of chronic lymphocytic leukemia (CLL). Even though venous thromboembolism (VTE) is a potential complication in CLL patients with superimposed autoimmune hemolytic anemia (AIHA), there are not enough studies on anticoagulation guidelines in these patients including prophylaxis.

Methods: National Inpatient Sample (NIS) ICD-10 codes were used between 2016-2020 to create a cohort of hospitalized patients with CLL and AIHA. Data was analyzed using STAT BE software. We implemented descriptive analysis and logistic regression analysis to examine the risk and outcome of VTE in this patient population. Additionally, we adjusted for confounding factors including hypertension, diabetes, end-stage renal disease, hyperlipidemia, and thrombophilia.

Results: Our analysis included 78,974 hospitalized patients with CLL. The mean age was 75 years, with men (60%) and white race (83%) making up the majority of our cohort. 1,866 hospitalized patients with CLL had AIHA, 13.5% of whom had VTE (Vs 10.3% in patients without AIHA). Pulmonary embolism occurred in 6.8% of CLL patients with AIHA (Vs 4.6% in patients without AIHA). The logistic regression model revealed that CLL patients with AIHA were strongly associated with an increased likelihood of VTE (OR 1.3, 95% CI, 1.2-1.5). Additionally, underlying thrombophilia was associated with a significantly increased risk of VTE (OR 6, 95% CI, 5-7.2), even though they comprised around 0.6% of patients with CLL (Vs 0.9% in CLL patients with AIHA). Patients with CLL and underlying comorbid conditions such as congestive heart failure, end-stage renal disease and thrombophilia significantly increased risk of mortality. However, the presence of AIHA didn't have a significant association with the risk of death.

Conclusion: CLL patients with AIHA have an increased likelihood of developing VTE in comparison to CLL patients without AIHA. This data warrants further investigation regarding anticoagulation in these patients.

No relevant conflicts of interest to declare.