Feature importance ranked according to feature gain. Higher feature gain means that the variable was more useful for categorizing patients as having normal or abnormal perfusion. Prior coronary artery disease (CAD) included a history of previous myocardial infarction (MI), percutaneous coronary intervention (PCI), or coronary artery bypass grafting. BMI – body mass index, CP – chest pain, ECG – electrocardiogram, LBBB – left bundle branch block, PVD – peripheral vascular disease.