Changes in risk factors trends in coronary surgery over the past decade – a single-center validation

Abstract

Introduction/Objective The risk factors in coronary patients indicated for surgery change during the years. The aim of this study was to analyze the trends of risk factors which enter into the composition of the European System for Cardiac Operative Risk Evaluation (EuroSCORE II).

Methods The research included 3996 patients who underwent coronary surgery from January 2012 to December 2020 at our clinic. For estimation of the risk factors and evaluation of the operative risk, the EuroSCORE II model was used. Kruskal–Wallis H test was used for testing differences of values of numerical variables between years. The calibration and the discriminative power of the EuroSCORE II were assessed by comparing the observed to the expected mortality ratio and by using area under the receiver operating characteristic curve (AUC).

Results Old age has shown a significant increasing trend (p < 0.0005), as well as diabetes mellitus on insulin therapy, before surgery (p = 0.004). The significant declining trend have shown: extracardiac arteriopathy (p = 0.003), critical preoperative condition (p = 0.013), preoperative NYHA Classes III or IV (p < 0.0005) and preoperative angina pectoris CCS Class IV (p < 0.0005). The mean value of the EuroSCORE II decreased from 1.73 to 1.53 (p < 0.0005). The observed mortality was 1.70% and the mean, predicted by the EuroSCORE II, was 1.75%. The O/E mortality ratio was 0.98; 95% confidence interval 0.95–1.03. The AUC was 0.825.

Conclusion Over the past decade the risk profile of patients for coronary surgery has changed. The mean value of the EuroSCORE II has a declining trend with a good predictive and discriminative power.

Keywords: cardiac surgery; risk factors; trends