Objective: To Validate the EuroSCORE II as a method for cardiac surgery risk stratification in Mexican adult population. Methods: We included adult patients undergoing to cardiac surgery, in order to determine the predictive value of EuroSCORE II on morbidity and mortality risk. Continuous variables are presented as mean ± SD or median with its interquartile range as appropriate; categorical variables were described as n, % or rate. To validate the EuroSCORE II scale, the assessment was done with Hosmer- Lemeshow (HL) test. In terms of discrimination, we used the features of the receiver operation characteristic (ROC) curves. Results: They were 704 patients, grouped into five categories: simple (one vessel) Coronary Artery Bypass Grafting (CABG) surgery, n= 299 (43%) cases. CABG revascularization (two or more vessels), n= 208 (30%). Double Procedure (CABG + valve replacement) 174 (25%) cases. Triple procedure (CABG + valve + aorta surgery) 23 (3.3%) patients. The mortality observed within 30 days of the surgery was 88 (12.5%). Meanwhile, the mean of the expected mortality predicted by EuroSCORE II was 3.63 ± 5.91 (95% CI: 3.19-4.06). The EuroSCORE II scale presented a good capacity for discrimination in the studied population reaching an area under the ROC curve of 0.821 (p < 0.000, 95% CI: 0.772-0.871). A calibration for the scale measured through logistic regression with goodness of adjustment of Hosmer-Lemeshow was determined (χ2 = 17.74, p = 0.64). Conclusion: EuroSCORE II showed moderate discrimination ability in general. The scale can be useful to identify some problems in our hospital, however, the mortality rate might be underestimated. Key words: Euroscore II; Adult Cardiac Surgery; Surgical Risk

Background: Currently, it has two methods of risk stratification in Congenital Heart surgery: Risk Adjustment in Congenital Heart Surgery(RACHS-1) and the complex integral Aristotelian (Aristotle). Although they have been tested in different countries, they have not been validated in hospitals of Mexico. Objectives: Validating both methods at 3rd Level Hospital (Cardiology Hospital CMN-SXXI, IMSS, Mexico City) for patients submitted to cardiac surgery due to congenital heart defects, between January 2015 and December 2016. Methods: A retrospective study of patients in the Hospital’s cardiology of the National Medical Center C-XXI, IMSS-Mexico, of any age and gender undergoing surgery for congenital heart disease elective or emergency with clinical record is prepared full. For studying validity, internal consistency, calibration, capacity for discrimination and morbidity and mortality between the risk levels were analyzed. Results: We included 201 patients with complete data. Both study scales in our study were statistically significant in the Logistic regression analysis (p = 0.001 and p = 0.000, respectively). Calibration test show to be non-significant for both scales (X2 of Hosmer-Lemeshow of 0.357 and 3.235 respectively). The areas under the ROC curve were 0.770 and 0.806, respectively, suggesting a good discrimination. The observed mortality was (6.46%). Nevertheless, each segment of the scales exceeded the expected in mortality according to the internationally accepted parameters for RACHS-1. Conclusion: We conclude that it is valid to use RACHS-1 and basic Aristotle for surgery of congenital heart disease, with a Cronbach’s alpha of 0.740. We suggested developing mechanisms to understand those variables that come out of the control of these instruments, such as the patient’s low weight and a history of reoperation. Key words: surgical risk; congenital heart disease; RACHS-1; Aristotle