Correlation of Euroscore-II, STS Risk Scoring Systems and Frailty Tests with Cardiac Histopathological Findings in Coronary Bypass Surgery

Various risk classification systems are used to predict postoperative mortality and morbidity development in cardiac surgery. Risk calculation with these systems is a guide in determining preoperative strategies, performing cost analyses, creating different treatment options and classifying diseases according to their severity. In recent years, tests defined as Frailty, which show how independently a person can perform daily living activities and are also associated with postoperative complications, have also been used. These tests allow for a personalized approach such as determining the most appropriate treatment options and pre- and postoperative rehabilitation. This study aims to evaluate the risk scores used to predict mortality during the preoperative preparation process in cases planned for elective Coronary Artery Bypass Graft (CABG) using the European System for Cardiac Operative Risk Evaluation (Euroscore)-II and Society of Thoracic Surgeons (STS) as well as Frailty with the Katz Index and modified Rockwood Clinical Frailty Scale, and to correlate the findings obtained from the histopathological study of the tissue sample taken from the right atrium during the operation with the test results. Secondary objectives are to investigate the compatibility of the age-related changes detected histopathologically with chronological age, to reveal which of the Frailty tests used gives better results in predicting mortality, and on the other hand, to reveal the relationship between Frailty tests and STS and Euroscore-II.