De-identified cardiac surgery dataset from Hospital Universitario Mayor-Méderi, a 900-bed tertiary referral centre located at 2,600 m above sea level in Bogotá, Colombia. The dataset includes all adult cardiac surgery procedures performed between January 2019 and December 2025.

De-identified cardiac surgery dataset supporting the following publication: Rodríguez Lima DR, et al. External Validation of EuroSCORE II, Additive EuroSCORE, and STS PROM v2.9 at 2,600 Metres Above Sea Level: A Retrospective Cohort Study from a Latin American Cardiac Surgery Centre. This is the first external validation of EuroSCORE II, Additive EuroSCORE, and STS PROM v2.9 in a population permanently residing at high altitude (≥2,500 m asl). Dataset Overview Rows: 1,486 (one per procedure) Columns: 50 (demographics, comorbidities, procedure variables, predicted probabilities, outcome) Primary outcome: inhospital_death — in-hospital all-cause mortality Predicted probability columns included: phat_euroscore2 — EuroSCORE II (Nashef 2012). AUC=0.757, O/E=4.73 phat_add_euroscore — Additive EuroSCORE (Roques 1999). AUC=0.740, O/E=0.59 phat_sts_prom — STS PROM v2.9 (Shahian 2018). AUC=0.806, O/E=5.61 (NaN if not STS-eligible) STS-eligible subgroup: sts_eligible=1, n=1,056 (isolated CABG/AVR/MVR/AVR+MVR)