SHAP feature importance analysis for 1 year, 3-year and 5 year CatBoost models (left to right). On the X-axis, the features are listed in decreasing order of their importance (top to bottom). The color represents the feature value–red for high values and blue for low values. For the features such as PWTDI lateral e’ velocity, PWTDI septal e’ velocity and ejection fraction–low (blue) values contribute towards high Shapley values i.e. towards mortality (class ‘dead’). On the other hand, for age, heart rate, mitral valve A wave velocity–high (red) values contribute towards mortality. A: mitral valve A wave velocity; DT: deceleration time; E: mitral valve E wave velocity; EF: ejection fraction; HR: heart rate; IVRT: Isovolumic relaxation time; IVS: interventricular septal thickness; LA: left atrial; LVEDV: left ventricular end diastolic volume; LVESV: left ventricular end systolic volume; LVIDd: left ventricular internal dimension at the end of diastole; LVIDs: left ventricular internal dimension at the end of systole; LVPW: left ventricular posterior wall thickness; PWTDI: pulsed-wave Tissue Doppler imaging for mitral annulus e’ velocity; TR: tricuspid regurgitation.