Readmission After Coronary Artery Bypass Grafting: Beyond the 30-Day Horizon

Hospital readmission after coronary artery bypass grafting (CABG) is an underappreciated but clinically and systemically important outcome. Beyond its role as a quality metric, readmissions represent a substantial burden on healthcare systems, increasing costs and straining hospital capacity.1 For patients, rehospitalization disrupts recovery, delays functional improvement, affects quality of life, and is associated with increased mortality.2 In the early postoperative period, readmissions are relatively common; up to 20% of patients are readmitted within 30 days, most often due to surgical site infection, pleural effusion, or atrial arrhythmias.3 These events are, at least in part, modifiable: strategies such as prehabilitation and adjunct intraoperative procedures like posterior pericardiotomy4 have been associated with reductions in early rehospitalization. However, beyond the first few months, readmissions increasingly reflect progression of underlying atherosclerotic cardiovascular disease, and this later phase is far less well characterized. Chan et al5 address this gap by providing an analysis of readmission patterns over 5 years following isolated CABG in a large, unselected UK cohort of more than 100,000 patients within a single healthcare system, capturing care across academic and non-tertiary centres. Of 101 759 patients discharged alive, 42% were readmitted within the first postoperative year, and 68% experienced at least one readmission within 5 years. These estimates are higher than those reported in randomized trials, where available data suggest 5-year readmission rates closer to 30%,6 although differences in definitions and ascertainment limit direct comparability. In the first 12 months, 15% of readmissions were for cardiovascular causes, most commonly arrhythmia, heart failure, and acute coronary syndromes, while 25% were related to the procedure, most commonly non-cardiac chest pain, wound complications, and anaemia. Beyond the first year, approximately one in 4 patients was readmitted for cardiovascular causes, predominantly arrhythmia, angina, and heart failure. The use of nationwide administrative data is both a strength and a limitation. The ability to track patients longitudinally across an entire healthcare system allows an accurate estimation of population-level readmission rates. However, such datasets lack clinical granularity and are vulnerable to coding errors and misclassification. The categorization of certain diagnoses, such as anemia or respiratory tract infection, as “procedure-related” is debatable, and the reliance on International Classification of Diseases (ICD) coding increases the risk of misclassification, particularly for conditions such as chest pain syndromes. Nonetheless, these limitations are unlikely to alter the overarching message: readmission after CABG over time is far more common than we tend to acknowledge. This challenges the frequent perception of CABG as a definitive intervention; patients return after surgery, and surgery does not conclude the patient journey. CABG is the benchmark procedure in cardiac surgery. Traditional long-term outcomes such as death, myocardial infarction, and stroke are well studied and remain central, yet other important outcomes, particularly those reflecting ongoing healthcare utilization, receive less attention. Patients undergoing CABG have advanced atherosclerotic cardiovascular disease, a chronic condition that requires sustained, multidisciplinary management. Surgery addresses coronary obstruction but does not modify the systemic disease process. The high burden of late readmission observed in this study is therefore not unexpected; it reflects the natural history of the disease when secondary prevention is suboptimal. Secondary prevention after CABG is often suboptimal, and CABG patients are less well treated than those undergoing PCI.7 While statin use, for example, is high early after surgery, adherence declines over time, and high-intensity therapy is not consistently maintained.8 Cardiac rehabilitation is similarly underutilized: despite clear benefits for functional recovery, quality of life, and rehospitalization, participation is not universal, and systematic enrolment should be standard practice.9 Psychosocial factors, including depression, are frequently under-recognized and undertreated, even though they have a meaningful impact on recovery and rehospitalization.10 Improving long-term outcomes after CABG will not come from further technical refinements alone, but from optimizing longitudinal care and aggressive risk factor modification. Importantly, secondary prevention must begin before discharge, not after. Readmissions after CABG are common and increasingly reflect the underlying disease. CABG is not a definitive intervention, and long-term outcomes depend as much on subsequent care as on the operation itself. No new data were generated or analysed with regard to this article. None declared.