Risk factors and mortality associated with venous thromboembolism in the elderly US population with chronic lymphocytic leukemia

Abstract

Background: Venous thromboembolism (VTE) causes morbidity and mortality in cancer patients. The association of VTE with known risk factors in chronic lymphocytic leukemia (CLL) is not known.

Objective: To examine risk factors and mortality associated with VTE in White, Black, and Asian CLL patients.

Methods: The United States SEER-Medicare database (2000-2015) was used for CLL patients ≥ 65 years. Logistic regression was used to examine VTE risk factors and Cox proportional regression was used to evaluate the effect of VTE on mortality in White, Black, and Asian CLL patients.

Results: Among 34,075 CLL patients, VTE was diagnosed in 11.6 % of 31,395 White, 14.6 % of 2062 Black and 6.3 % of 618 Asian patients. Risk of having VTE was, OR_a = 1.2 (95 % CI, 1.0-1.4) for Black patients and OR_a = 0.5 (95 % CI, 0.4-0.7) for Asian patients compared to White patients. Anemia and heart failure were associated with VTE in all three racial cohorts and were the only risk factors in Asian patients. Other risk factors in White patients were the same as in the overall population, including hypertension, obesity, COPD, kidney disease, diabetes, hyperlipidemia, myocardial infarction, and chemotherapy. In Black patients, other risk factors were hypertension, and chemotherapy. Mortality was slightly higher with VTE in the overall population and in White patients.

Conclusion: There was difference in VTE risk factors in White, Black, and Asian patients. VTE was marginally associated with mortality in CLL patients. Our findings may help to identify patients at higher risk of VTE in racially diverse CLL populations.

Keywords: Chronic lymphocytic leukemia (CLL); Deep vein thrombosis (DVT); Leukemia; Mortality; Pulmonary embolism (PE); Venous thromboembolism (VTE).