Society of Thoracic Surgeons 2021 Adult Cardiac Surgery Risk Models for Multiple Valve Operations

Abstract Background The STS Quality Measurement Task Force has developed risk models and composite performance measures for isolated coronary artery bypass grafting surgery (CABG), isolated aortic valve replacement (AVR), isolated mitral valve replacement or repair (MVRR), AVR+CABG, and MVRR+CABG. To further enhance its portfolio of risk-adjusted performance metrics, STS has developed new risk models for multiple valve operations +/- CABG procedures. Methods Using July 2011 to June 2019 STS Adult Cardiac Surgery Database (ACSD) data, risk models for AVR+MVRR (n=31,968) and AVR+MVRR+CABG (n=12,650) were developed with the following endpoints: operative mortality, major morbidity (any one or more of the following: cardiac reoperation; deep sternal wound infection/mediastinitis; stroke; prolonged ventilation; and renal failure), and combined mortality and/or major morbidity. Data were divided into development (July 2011 – June 2017, n=35,109) and validation (July 2017 – June 2019, n=9,509) samples. Predictors were selected by assessing model performance and clinical face validity of full and progressively more parsimonious models. Performance of the resulting models was evaluated by assessing discrimination and calibration. Results C-statistics for the overall population of multiple valve +/- CABG procedures were 0.7086, 0.6734, and 0.6840 for mortality, morbidity, and combined mortality and/or morbidity in the development sample, and 0.6953, 0.6561, and 0.6634 for the same outcomes, respectively, in the validation sample. Conclusions New STS-ACSD risk models have been developed for multiple valve +/- CABG operations, and these models will be used in subsequent STS performance metrics.