Validation of EuroSCORE II in a modern cohort of patients undergoing cardiac surgery.

OBJECTIVE: We aimed to validate the new EuroSCORE II risk model in a contemporary cardiac surgery practice in the United Kingdom (UK). METHODS: The original logistic EuroSCORE was compared to EuroSCORE II with regard to accuracy of predicting in-hospital mortality. Analysis was performed on isolated coronary artery bypass grafts (CABG; n= 2913), aortic valve replacement (AVR; n= 814), mitral valve surgery (MVR; n= 340), combined AVR and CABG (n= 517), aortic (n= 350) and miscellaneous procedures (n= 642), and the above cases combined (n= 5576). RESULTS: In a single-institution experience, EuroSCORE II is a reasonable risk model for in-hospital mortality from isolated CABG (C-statistic 0.79, Hosmer-Lemeshow P= 0.052) and aortic procedures (C-statistic 0.81, Hosmer-Lemeshow P= 0.43), and excellent for mitral valve surgery (C-statistic 0.87, Hosmer-Lemeshow P = 0.6). EuroSCORE II is better than the original EuroSCORE, using contemporaneous data for combined AVR and CABG operations (C-statistic 0.74, Hosmer-Lemeshow P= 0.38). However, EuroSCORE II failed to improve on the original EuroSCORE model for isolated AVR (C-statistic 0.69, Hosmer-Lemeshow P= 0.07) and miscellaneous procedures (C-statistic 0.70, Hosmer-Lemeshow P= 0.99). EuroSCORE II has better calibration than the original EuroSCORE or the Society of Cardiothoracic Surgeons of Great Britain and Ireland (SCTS) modified EuroSCORE for cumulative sum survival (CUSUM) curves.