Five-year hospital readmission after isolated coronary artery bypass grafting in the United Kingdom

Abstract OBJECTIVES Data on hospital readmission and secondary care utilisation after coronary artery bypass grafting beyond 30 days remains limited. We aim to address this gap by reporting cardiovascular and procedure-related readmission rates in the 60 months after primary isolated surgical revascularisation in the UK. METHODS All patients who underwent isolated coronary artery bypass grafting from January 2013 to April 2025 from the UK National Adult Cardiac Surgery Audit dataset were included. All cause readmissions to any NHS hospital during the first 60 months of follow-up were analysed from the Hospital Episode Statistics dataset. The relation to the time before, during, and after the COVID-19 pandemic was also investigated. Finally, the primary and secondary diagnoses, as well as any procedure(s) undertaken during readmission, were evaluated. RESULTS A total of 101759 patients were identified (84% male, median age 66.9 years (1st and 3rd Quartile: 59.7, 73.6). Of these 69426 patients, required readmission for any cause. The cumulative incidence of readmission at 12 and 60 months was 42.0% and 68.2%, respectively. The overall readmission rate during the first lockdown to the third lockdown relaxation of the COVID-19 pandemic was 42.0% (Ranged: 40.7% to 45.0%). No significant differences in readmission rates were observed during the COVID-19 pandemic. At 12 months, cardiovascular-related readmissions accounted for 15% (n = 13529) of all readmissions, with arrhythmia 25%, heart failure 19% and acute coronary syndrome 15.2%. The primary diagnoses between 13 to 60 months 24.7% (n = 17162) were arrhythmia 22.2%, angina pectoris 19.4% and heart failure 17.1%. The overall incidence of urgent repeat revascularisation during readmission at 12 and 60 months was 1.71% and 4.20%, respectively. The primary readmission diagnoses related to the surgical procedure (excluding cardiovascular-related) in the first 12 months was 25.5% (n = 23047), with non-cardiac chest pain 30.1%, surgical wound disruption/infection 16.8% and anaemia 15.0%. Between 13–60 months, procedure-related primary diagnoses accounted for 26.1% (n = 18143), of which non-cardiac chest pain 35.6%, anaemia 26.2%, and respiratory tract infection 20.8%. CONCLUSIONS Analysis of this unselected UK cohort reveals that cardiovascular-related readmission represented one-quarter of all readmissions at five years after the index CABG. This high readmission rate underscores the need for further research to understand the underlying causes and implement strategies to optimise resource use.