Platelet Counts Are Significantly Associated With VTE Risk 1 Year After Leukemia Diagnosis

Researchers have identified the predictors of venous thromboembolism (VTE) in patients within 1 year of acute leukemia diagnosis, according to data presented at the American Society of Hematology’s 2021 Annual Meeting. Both low and high platelet counts were associated with increased risk of cancer‑associated VTE.

To explore the incidence and predictors of VTE in patients with acute myeloid leukemia (AML) or lymphoblastic leukemia (ALL), researchers at Case Western Reserve University retrospectively studied a cohort of patients with an AML or ALL diagnosis within the previous 5 years by using data from the electronic medical records of more than 300 major US hospitals.

The study’s primary endpoint was the incidence of cancer-associated VTE (defined as deep vein thrombosis, pulmonary embolism, or superficial vein thrombosis) within 1 year of leukemia diagnosis.  The researchers compared baseline characteristics and laboratory values between patients with a cancer-associated VTE within 1 year of leukemia diagnosis and patients who did not have a VTE within that time period. 

They used 2-sided chi-square testing to evaluate baseline variables via univariate analysis and considered a p-value of less than 0.05 statistically significant. Their analysis included data from nearly 20,000 adults, and the age of this study group ranged from 20 to 79 years. As a result, they found that the incidence of VTE within 1 year of acute leukemia diagnosis was approximately 8%. 

Of the baseline variables evaluated, history of VTE had the greatest association with having a VTE within this period. Other associated variables included being older than 60 years of age, having a White or Black race, or having obesity.  

In addition, current smoking or remote smoking history, Factor V Leiden diagnosis, and presence of a central venous catheter, anemia, or leukocytosis were all associated with VTE within 1 year of leukemia diagnosis, as was use of an antineoplastic agent, erythropoietin, or pegylated asparaginase. In contrast, age 20 to 39 years and Asian race were inversely associated with VTE.

“Risk of VTE was, however, increased regardless of platelet counts, which emphasizes the need to consider surveillance or thromboprophylaxis strategies in AML/ALL patients with thrombocytopenia with presumed high bleeding risk,” the researchers concluded.

—Ellen Kurek

Reference:

Grinsztejn E, Nayak LV, Kapoor S. Predictors of venous thromboembolism in patients with acute myeloid leukemia or acute lymphoblastic leukemia. Paper presented at: American Society of Hematology 2021 Annual Meeting & Exposition; December 11–14, 2021; Atlanta, Georgia. https://ash.confex.com/ash/2021/webprogram/Paper153294.html