Medical versus invasive management in patients with non-ST segment elevation myocardial infarction and prior coronary artery bypass grafting: which approach improves outcomes?

Abstract Background Patients with a history of coronary artery bypass grafting (CABG) who present with acute coronary syndrome (ACS) have poor outcomes, and the optimal treatment strategy for this population remains unclear. The benefits of routine invasive management in patients with prior CABG presenting with non-ST-elevation myocardial infarction (NSTEMI) are uncertain, as these patients were often excluded from pivotal trials. Purpose We aimed to describe the clinical characteristics and outcomes of patients with NSTEMI and prior CABG, comparing medical vs. invasive treatment strategies. Additionally, the invasive treatment group was categorized into native vs. graft vessels. Methods This was a retrospective, observational, and analytical study. Among 4.400 NSTEMI patients admitted between 2010 and 2023, 191 (4.3%) with previous CABG were selected. The outcomes analyzed included all-cause mortality, recurrent myocardial infarction, and cardiovascular hospitalization at 1-year. Results Of the 191 patients, 94 (49.2%) received medical treatment, and 97 (50.8%) underwent percutaneous coronary intervention (PCI). There were no significant differences in demographic or clinical characteristics between the groups. The mean age was 72.6±9 years, 82.7% were male and 17.3% were female. In the medical management group (MMG), 90.4% underwent angiography without PCI, while 9.6% had no invasive assessment. In revascularized patients, 64.9% underwent PCI on native vessels, and 35.1% on bypass grafts. During follow-up, the 1-year mortality was significantly higher in MMG (24.5%) compared to the PCI group (10.3%) (p=0.010). When comparing PCI in native vessels vs. grafts, no significant outcome differences were found. After adjusting for potential confounders, PCI was associated with a 62.5% reduction in death risk at 1-year compared to MMG (aHR= 0.375, p=0.014). The results persisted after propensity score matching, with higher 1-year mortality rates in the MMG (23.5%) vs. PCI (9.4%) (p=0.019). Hazard ratio was 0.38 (p=0.022), confirming the protective effect associated with the PCI group. Conclusion This retrospective study suggests that patients undergoing PCI achieve better outcomes, including lower mortality, compared to medical treatment. However, selection bias remains a confounding issue, and some contributing factors may not be accounted for in adjusted models. Further research is required to optimize treatment strategies for this population.Medical versus Invasive management