Frailty is a predictor of short- and mid-term mortality after elective cardiac surgery independently of age

OBJECTIVES: Assessment of perioperative risk of elderly patients in cardiac surgery is difficult, and most of the common risk scores show over- or underestimation. Two frailty scores, the comprehensive assessment of frailty (CAF) score and the Frailty predicts death One yeaR after CArdiac Surgery Test (FORECAST), were developed as additional tools to estimate the preoperative mortality risk, taking into consideration the frailty status of elderly patients. METHODS: Four hundred and fifty patients who were referred for elective cardiac surgery were included. All the patients were assessed with the CAF test and the FORECAST. Thirty-day and 1-year mortality were evaluated by telephone interview. Univariate and bivariate logistic regression were performed to test the predictive power of the tests on mortality. Correlation of the scores with age was calculated with Spearman ranks. Three commensurate groups were built for each of the frailty scores and the outcome was compared between the groups. All analyses were performed for Society of Thoracic Surgeons (STS) and European System for Cardiac Operative Risk Evaluation (EuroSCORE) accordingly. RESULTS: A total of 227 male and 223 female patients were included. Thirty-day mortality was 6.1%, and 1-year mortality was 13.3%. Logistic regression showed that both scores are able to predict 30-day as well as 1-year mortality. Bivariate logistic regression showed that both frailty scores give relevant additional information to the STS and EuroSCORE for the prediction of 1-year mortality. The frailty scores were only weakly correlated with age in contrast to STS and EuroSCORE and therefore can be used as indicator of the biological age of patients besides the numerical age. Survival up to 1 year was relevantly reduced in the group of patients with the higher frailty scores. CONCLUSIONS: CAF and FORECAST are additional tools to evaluate elderly patients adequately before elective cardiac surgery, and showed an association with short- and mid-term mortality independently of age.