The relationship between the Hospital Frailty Risk Score (HFRS)-based frailty risk and outcomes after coronary artery bypass grafting (CABG) is yet unclear. The objective of this study was to investigate the relationship between preoperative frailty risk as assessed by the HFRS and postoperative outcomes in patients undergoing CABG. This observational study used the diagnosis procedure combination (DPC) system in Japan (2014–2017). In total, 35,015 adults aged ≥ 65 years and diagnosed with angina pectoris and acute myocardial infarction who had undergone CABG were enrolled. We investigated the association between the HFRS-based frailty risk and the home discharge rate, as well as the prevalence of complications. Multilevel logistic regression analysis revealed that having an HFRS ≥ 5 was a determinant of lower home discharge rate (odds ratio [OR] 0.60, 95% confidence interval [CI] 0.49–0.74, P <0.01), aspiration pneumonia (OR 2.25, 95%CI 1.27–3.96, P <0.01) and disuse syndrome (OR 1.90, 95%CI 1.23–2.94, P <0.01). Preoperative stratification of frailty risk using HFRS may help in predicting postoperative progress and in planning postoperative rehabilitation.
