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Identifying Patients with Polycythemia Vera at Risk of Thrombosis after Hydroxyurea Initiation: The Polycythemia
Srdan Verstovsek1, Ivan Krečak2,3, Florian H Heidel4
1Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
Insights
Patients with polycythemia vera (PV) face high risks of thromboembolic events (TE). Machine learning identified lymphocyte percentage, neutrophil percentage, and red cell distribution width as key TE risk markers in PV patients.
Area of Science:
- Hematology
- Oncology
- Data Science
Background:
- Polycythemia vera (PV) patients have a high risk of thromboembolic events (TE).
- Real-world data is crucial for understanding TE risk factors in PV.
- Treatment strategies for PV aim to mitigate TE risk.
Purpose of the Study:
- To identify key markers associated with TE risk in a large, real-world PV population.
- To develop a predictive model for TE risk using machine learning.
- To establish optimal thresholds and a decision tree for identifying high-risk patients.
Main Methods:
- Utilized the Optum® de-identified Electronic Health Record dataset for 82,960 PV patients.
- Applied machine learning models to identify TE risk markers.
- Validated the model using an independent dataset.
Main Results:
- Analyzed incidence rates of TE in patients treated with hydroxyurea (HU) alone versus HU followed by ruxolitinib.
- Machine learning model identified lymphocyte percentage (LYP), neutrophil percentage (NEP), and red cell distribution width (RDW) as significant TE risk markers.
- Optimal thresholds for LYP, NEP, and RDW were established, leading to a derived decision tree.
Conclusions:
- A machine learning-derived decision tree using LYP, NEP, and RDW can identify PV patients at high risk for TE.
- These laboratory markers can aid in treatment decisions and optimize patient management for PV.
- The findings support the use of readily available lab markers for proactive TE risk assessment in PV.
Abstract:
Patients with polycythemia vera (PV) are at significant risk of thromboembolic events (TE). The PV-AIM study used the Optum® de-identified Electronic Health Record dataset and machine learning to identify markers of TE in a real-world population. Data for 82,960 patients with PV were extracted: 3852 patients were treated with hydroxyurea (HU) only, while 130 patients were treated with HU and then changed to ruxolitinib (HU-ruxolitinib). For HU-alone patients, the annualized incidence rates (IR; per 100 patients) decreased from 8.7 (before HU) to 5.6 (during HU) but increased markedly to 10.5 (continuing HU). Whereas for HU-ruxolitinib patients, the IR decreased from 10.8 (before HU) to 8.4 (during HU) and was maintained at 8.3 (after switching to ruxolitinib). To better understand markers associated with TE risk, we built a machine-learning model for HU-alone patients and validated it using an independent dataset. The model identified lymphocyte percentage (LYP), neutrophil percentage (NEP), and red cell distribution width (RDW) as key markers of TE risk, and optimal thresholds for these markers were established, from which a decision tree was derived. Using these widely used laboratory markers, the decision tree could be used to identify patients at high risk for TE, facilitate treatment decisions, and optimize patient management.
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