Acute Coronary Syndrome Following Coronary Artery Bypass Grafting: Clinical Characteristics, Angiographic Patterns, Management Strategies, and In-Hospital Outcomes from a Prospective Cohort Study

Abstract

Objectives: To evaluate the clinical characteristics, angiographic findings, management strategies, and in-hospital outcomes of patients with previous CABG presenting with ACS. Methodology: This prospective observational cohort study was conducted between November 2024 and October 2025. Consecutive adult patients with a history of CABG presenting with ACS were enrolled. Data regarding clinical characteristics, treatment strategies, procedural details, and in-hospital outcomes were collected prospectively. Results: A total of 279 patients were included, with a mean age of 64.5 ± 8.2 years; 87.8% were male. Hypertension and diabetes mellitus were present in 83.9% and 70.6% of patients, respectively. Unstable angina was the most common presentation (57.0%), followed by NSTEMI (30.1%) and STEMI (12.9%). Angiography demonstrated extensive native coronary artery disease involving the LAD (96.9%), LCX (93.4%), and RCA (91.7%). Saphenous vein graft obstruction was most frequently observed in SVG-RCA (52.4%) and SVG-OM1 (38.9%), whereas arterial graft failure was less common. PCI was performed in 41.6% of patients, achieving a procedural success rate of 95.7%. In-hospital mortality was low (1.4%), while acute kidney injury (3.6%), life-threatening arrhythmias (3.9%), and stroke (0.4%) occurred infrequently. Multivariable analysis identified Killip class III/IV as an independent predictor of composite in-hospital adverse events (adjusted OR 45.65, 95% CI 1.82–1145.59; p=0.020). Conclusion: Patients with prior CABG presenting with ACS constitute a high-risk population characterized by extensive native coronary artery disease, significant graft pathology, and multiple cardiovascular comorbidities. Nevertheless, contemporary management strategies, including selective PCI and optimized medical therapy, are associated with favorable short-term outcomes and low in-hospital mortality.