Primary predictors

All risk factors relevant to SinoSCORE^{9 10} and STS^{12 13} risk calculations were collected. Available data were entered into each risk calculation using appropriate definitions. In cases where there were minor discrepancies between the definitions of various risk factors (chronic obstructive pulmonary disease (COPD), atrial fibrillation and so on) between the two models, reasonable approximations were made (see online supplementary file.) Based on original SinoSCORE methodology, a SinoSCORE was then calculated for each patient. STS mortality risk scores were retrieved from the HeartSource database.⁹ SinoSCORE was calculated for all patients undergoing CABG, including those with associated valve surgery, whereas separate STS risk models were employed for each isolated CABG and combined CABG/valve procedure.^{12 13} In accordance with original SinoSCORE methodology, patients were stratified into low-risk, medium-risk and high-risk groups according to their respective SinoSCOREs (low: <1, medium: 1< and <6, high: ≥6).

heartasia-2017-010995supp001.doc