A Simplified Scoring System to Predict In-Hospital Mortality of Leukapheresis in Patients With Leukemia

The American Society for Apheresis recommends leukapheresis as a category II recommendation for symptomatic hyperleukocytosis. Mortality in these patients varies between 8%-29%. However, no tool is currently available to assess the mortality risk following the procedure. This study aims to assess the factors associated with in-hospital mortality and develop a risk stratification tool consisting of clinically relevant variables to categorize patients based on their mortality risk following the procedure. The National Inpatient Sample Database (2016-2021) and ICD-10 coding were utilized to identify adults with leukemia who underwent leukapheresis. Multivariate logistic regression models were constructed to identify independent factors of mortality. A scoring system was constructed to identify the risks of mortality using the variables in the model and their associated odds ratio (OR). The cumulative risk score was divided into three strata: low (mortality < 20%), intermediate (20%-50%), and high risk (> 50%). Of the estimated 3555 patients who underwent leukapheresis, 40.1% also received chemotherapy. Most patients who underwent leukapheresis had myeloid leukemia (52.2%), followed by lymphoid leukemia (14.2%), monocytic leukemia (6.2%), and the remaining were other types of leukemia. Variables incorporated into the scoring system include: monocytic leukemia, age over 50, morbid obesity, and interventions performed before leukapheresis, such as mechanical ventilation and blood transfusions. The cumulative mortality score ranged from 0 to 30, categorizing patients into high risk (score > 13), intermediate risk (6-13), and low risk (0-5). The risk score demonstrated a performance with an area under the curve of 0.82. A novel simplified scoring tool to predict in-hospital mortality in leukemia patients requiring leukapheresis is presented here. This tool can assist in preprocedural risk assessment, help guide management planning, and consideration of other treatment modalities.