Expanding interpretability through complexity reduction in machine learning‐based modelling of cardiovascular disease: A myocardial perfusion imaging PET/CT prognostic study
: Lehtonen, Eero; Teuho, Jarmo; Vatandoust, Monire; Knuuti, Juhani; Knol, Remco J. J.; van der Zant, Friso M.; Juarez-Orozco, Luis Eduardo; Klen, Riku
Publisher: Wiley-Blackwell
: HOBOKEN
: 2025
: European Journal of Clinical Investigation
: European Journal of Clinical Investigation
: EUR J CLIN INVEST
: e14391
: 55
: S1
: 10
: 0014-2972
: 1365-2362
DOI: https://doi.org/10.1111/eci.14391
: https://doi.org/10.1111/eci.14391
: https://research.utu.fi/converis/portal/detail/Publication/491843613
Background
Machine learning-based analysis can be used in myocardial perfusion imaging data to improve risk stratification and the prediction of major adverse cardiovascular events for patients with suspected or established coronary artery disease. We present a new machine learning approach for the identification of patients who develop major adverse cardiovascular events. The new method is robust against the deleterious effect of outliers in the training set stratification and training process.
MethodsThe proposed sum-of-sigmoids model is obtained by averaging the contributions of various input variables in an ensemble of XGBoost models. To illustrate its performance, we have applied it to predict major adverse cardiovascular events from advanced imaging data extracted from rest and adenosine stress 13N-ammonia positron emission tomography myocardial perfusion imaging polar maps. There were 1185 individual studies performed, and the event occurrence was tracked over a follow-up period of 2 years.
ResultsThe sum-of-sigmoids model achieved a prediction accuracy of .83 on the test set, matching the performance of significantly more complex and less interpretable models (whose accuracies were .83–.84).
ConclusionThe sum-of-sigmoids model is interpretable and simple, while achieving similar prediction accuracy to significantly more complex machine learning models in the considered prediction task. It should be suitable for applications such as automated clinical risk stratification, where clear and explicit justification of the classification procedure is highly pertinent.
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Authors acknowledge financial support by grants from the Academy of Finland (PI Dr. Juhani Knuuti, Academy Decision Number 351482), the Finnish Cultural Foundation (Maire and Aimo Mäkinen Fund) and the State Research Funding of Turku University Hospital (under grant 30046).