RELATIONSHIP BETWEEN DIABETES AND LONG-TERM OUTCOMES IN PATIENTS UNDERGOING ISOLATED CORONARY ARTERY BYPASS GRAFTING.

Background and Aim: Diabetes is a known risk factor for coronary artery disease, but its impact after coronary artery bypass grafting (CABG) remains uncertain, with limited data on long-term outcomes. This study aims to assess how diabetes affects 10-year outcomes following CABG. Methods: The PRedictIng long term Outcomes afteR Isolated coronary arTery bypass surgery (PRIORITY) project is an observational cohort study that combines two prospective multicenter studies from 2002-2004 and 2007-2008 on isolated CABG. Follow-up data were gathered from administrative databases and extended up to 10 years post-surgery. Primary outcome was a composite of Major Adverse Cardiac and Cerebrovascular Events (MACCE). Baseline differences between patients with and without diabetes were adjusted using propensity score inverse probability of treatment. Time-to-event data were analyzed through Cox- regression and competing risk analysis. Results: The study included 10989 patients with complete follow-up information who had isolated CABG, with 32.3% having diabetes. Diabetic patients exhibited a higher 10-year risk for MACCE (weighted HR 1.22, 95% CI 1.17 - 1.27, p<0.001), mortality (HR 1.39, 95% CI 1.32 - 1.47, p<0.001), stroke (HR 1.33, 95% CI 1.21 - 1.47), and myocardial infarction (MI) (HR 1.16, 95% CI 1.07 - 1.25, p<0.001). However, diabetes was not linked to higher incidence of repeat revascularization (HR 1.03, 95% CI 0.95 - 1.12, p=0.41). Conclusions: Diabetic patients faced poorer outcomes, with a higher 10-year incidence of myocardial infarction and a lower rate of repeat revascularization, suggesting that diabetes may have a more detrimental effect on microvascular health rather than on the grafts.