Algorithmic fairness in machine-learning models for determining the progression or recurrence of cardiovascular disease in racialized populations: a scoping review.

Objective: To examine how algorithmic fairness is measured, operationalized, and reported in machine learning (ML) models designed to predict or support secondary prevention of cardiovascular disease (CVD) outcomes including progression, recurrence, readmission, and post-index mortality in racialized populations. Materials and Methods: This scoping review was conducted in accordance with PRISMA-ScR guidelines and registered with the Open Science Framework (OSF registration: https://doi.org/10.17605/OSF.IO/9W67V). Systematic searches of OVID MEDLINE, EMBASE, Scopus, and CENTRAL were performed to identify studies evaluating fairness in ML models applied to secondary cardiovascular outcomes. Results: Of 2669 records screened, three retrospective cohort studies met inclusion criteria. All studies used large-scale electronic health record data from the United States and evaluated model performance across racial subgroups. Only one study implemented fairness-aware model development, reporting improvements of approximately 5%-12% in equity-related metrics, accompanied by modest trade-offs in calibration and sensitivity. The remaining studies assessed fairness post hoc and demonstrated limited ability to mitigate subgroup performance differences. Discussion: Most full-text studies excluded during screening addressed fairness in predicting primary CVD incidence rather than secondary outcomes, highlighting a substantial gap in the literature. Across included studies, observed fairness limitations appeared to be driven largely by upstream structural and data-generating factors such as representation, care patterns, and documentation rather than algorithmic design alone. Conclusion: Evidence on algorithmic fairness in ML models for secondary cardiovascular outcomes remains sparse. Improved reporting of subgroup performance, missingness, and calibration, alongside integration of fairness throughout model development, is necessary before equitable clinical deployment. Study Registration: Open Science Framework: https://doi.org/10.17605/OSF.IO/9W67V.