Abstract
Background Current risk stratification tools in pulmonary arterial hypertension (PAH) are limited in their discriminatory abilities, partly due to the assumption that prognostic clinical variables have an independent and linear relationship to clinical outcomes. We sought to demonstrate the utility of Bayesian network-based machine learning in enhancing the predictive ability of an existing state-of-the-art risk stratification tool, REVEAL 2.0.
Methods We derived a tree-augmented naïve Bayes model (titled PHORA) to predict 1-year survival in PAH patients included in the REVEAL registry, using the same variables and cut-points found in REVEAL 2.0. PHORA models were validated internally (within the REVEAL registry) and externally (in the COMPERA and PHSANZ registries). Patients were classified as low-, intermediate- and high-risk (<5%, 5–20% and >10% 12-month mortality, respectively) based on the 2015 European Society of Cardiology/European Respiratory Society guidelines.
Results PHORA had an area under the curve (AUC) of 0.80 for predicting 1-year survival, which was an improvement over REVEAL 2.0 (AUC 0.76). When validated in the COMPERA and PHSANZ registries, PHORA demonstrated an AUC of 0.74 and 0.80, respectively. 1-year survival rates predicted by PHORA were greater for patients with lower risk scores and poorer for those with higher risk scores (p<0.001), with excellent separation between low-, intermediate- and high-risk groups in all three registries.
Conclusion Our Bayesian network-derived risk prediction model, PHORA, demonstrated an improvement in discrimination over existing models. This is reflective of the ability of Bayesian network-based models to account for the interrelationships between clinical variables on outcome, and tolerance to missing data elements when calculating predictions.
Abstract
Bayesian machine-learning algorithms can improve discrimination of risk stratification in PAH. Our BN model, titled PHORA, predicts 1-year mortality with an AUC of 0.8, risk-stratifies patients effectively and is validated in two independent PAH registries. https://bit.ly/2xc0EVJ
Footnotes
Conflict of interest: M.K. Kanwar reports grants from NIH/NHBLI, during the conduct of the study.
Conflict of interest: M. Gomberg-Maitland reports consultancy/steering committee, data monitoring board work for Acceleron, Actelion, Complexa, Gossamer Bio, Reata, and Neuroderm; George Washington School of Medicine and Health Sciences has received grants for research from Altavant and United Therapeutics; and is a member of the scientific advisory board for United Therapeutics, outside the submitted work.
Conflict of interest: M. Hoeper reports personal fees from Actelion, Bayer, MSD and Pfizer, outside the submitted work.
Conflict of interest: C. Pausch has nothing to disclose.
Conflict of interest: D. Pittrow reports personal fees from Actelion, Bayer, Amgen, Boehringer Ingelheim, Sanofi, MSD and Biogen, outside the submitted work.
Conflict of interest: G. Strange reports grants from Actelion Pharmaceuticals, GlaxoSmithKline and Bayer Pharmaceuticals, during the conduct of the study.
Conflict of interest: J.J. Anderson reports grants from GlaxoSmithKline, non-financial support from Actelion and Bayer, personal fees from AstraZeneca, outside the submitted work.
Conflict of interest: C. Zhao is an employee of Actelion Pharmaceuticals US, Inc., a Janssen Pharmaceutical Company of Johnson & Johnson.
Conflict of interest: J.V. Scott has nothing to disclose.
Conflict of interest: M.J. Druzdzel is a partner at BayesFusion, LLC.
Conflict of interest: J. Kraisangka has nothing to disclose.
Conflict of interest: L. Lohmueller has nothing to disclose.
Conflict of interest: J. Antaki reports grants from NIH/NHLBI (R01 HL134673), during the conduct of the study.
Conflict of interest: R.L. Benza reports grants from NIH/NHLBI (R01 HL134673), Actelion, United Therapeutics and Bayer, during the conduct of the study.
Support statement: Funding for this work was provided by National Institutes of Health, Division of National Heart, Lung, and Blood Institute grants R01 HL134673, PHORA: Pulmonary Hypertension Outcomes Risk Assessment. Funding information for this article has been deposited with the Crossref Funder Registry.
- Received January 9, 2020.
- Accepted April 22, 2020.
- Copyright ©ERS 2020