Evaluation of Machine Learning Approaches for Predicting Warfarin Discharge Dose in Cardiac Surgery Patients:
Lindsay Dryden1, Jacquelin Song1, Teresa J Valenzano1
1Unity Health Toronto, Toronto, ON, Canada.
JMIR Cardio
|December 6, 2023
Summary
Machine learning algorithms can predict warfarin doses for cardiac surgery patients, improving anticoagulation. These models enhance the accuracy of achieving therapeutic international normalized ratio (INR) levels at discharge.
Area of Science:
- Cardiovascular Surgery
- Pharmacology
- Machine Learning
Background:
- Cardiac surgery patients exhibit increased warfarin sensitivity, raising risks of adverse events.
- Accurate warfarin dosing is crucial for effective anticoagulation post-cardiac surgery.
- Predictive algorithms are needed to optimize warfarin management in this population.
Purpose of the Study:
- To develop and validate machine learning algorithms for predicting optimal warfarin dosage.
- To achieve a therapeutic international normalized ratio (INR) at discharge for cardiac surgery patients.
- To compare different machine learning models for warfarin dose prediction accuracy.
Main Methods:
- Utilized data from 1031 cardiac surgery encounters initiating warfarin.
- Compared penalized linear regression, k-nearest neighbors, random forest, gradient boosting, MARS, and an ensemble model.
- Developed separate models for target INRs of 2.0-3.0 and 2.5-3.5, using cross-validation and evaluating mean absolute error (MAE).
Main Results:
- Random forest regression best predicted doses for target INR 2.0-3.0 (MAE 1.13 mg, 39.5% within 20% of target).
- An ensemble model excelled for target INR 2.5-3.5 (MAE 1.11 mg, 43.6% within 20% of target).
- Implementation of algorithms increased therapeutic INR discharge rates from 47.5% to 61.1%.
Conclusions:
- Machine learning models effectively predict warfarin doses using routine clinical data.
- These algorithms can guide initial warfarin dosing in cardiac surgery patients.
- Optimized anticoagulation management is achievable through predictive modeling.


