Naive Bayes Prediction of the Development of Cardiac Events in Heart Failure With Preserved Ejection Fraction in an Outpatient Clinic　― Beyond B-Type Natriuretic Peptide ―

BACKGROUND: The heterogeneity of B-type natriuretic peptide (BNP) levels among individuals with heart failure and preserved ejection fraction (HFpEF) makes predicting the development of cardiac events difficult. This study aimed at creating high-performance Naive Bayes (NB) classifiers, beyond BNP, to predict the development of cardiac events over a 3-year period in individual outpatients with HFpEF. METHODS AND RESULTS: We retrospectively enrolled 234 outpatients with HFpEF who were followed up for 3 years. Parameters with a coefficient of association ≥0.1 for cardiac events were applied as features of classifiers. We used the step forward method to find a high-performance model with the maximum area under the receiver operating characteristics curve (AUC). A 10-fold cross-validation method was used to validate the generalization performance of the classifiers. The mean kappa statistics, AUC, sensitivity, specificity, and accuracy were evaluated and compared between classifiers learning multiple factors and only the BNP. Kappa statistics, AUC, and sensitivity were significantly higher for NB classifiers learning 13 features than for those learning only BNP (0.69±0.14 vs. 0.54±0.12 P=0.024, 0.94±0.03 vs. 0.84±0.05 P<0.001, 85±8% vs. 64±20% P=0.006, respectively). The specificity and accuracy were similar. CONCLUSIONS: We created high-performance NB classifiers for predicting the development of cardiac events in individual outpatients with HFpEF. Our NB classifiers may be useful for providing precision medicine for these patients.