AHA Scientific Sessions 2026 Abstract · Nov 2, 2026
Initial Diabetes Therapy After Coronary Artery Bypass Grafting and Long-Term Outcomes
By Tam V, Schaff HV, Thao V et al.
Background: Type 2 diabetes mellitus (DM) is common among patients undergoing coronary artery bypass grafting (CABG) and is associated with adverse long-term outcomes. Although contemporary glucose-lowering therapies confer cardiovascular benefit in broad populations, optimal post-discharge diabetes management after CABG remains uncertain. Hypothesis: Initial post-discharge DM therapy after CABG is associated with differential long-term survival and cardiovascular outcomes. Methods: Using the OptumLabs Data Warehouse, we analyzed adults with type 2 DM undergoing isolated CABG from 2012-2024. Patients were classified by initial post-discharge therapy: no treatment, metformin, insulin, or glucagon-like peptide-1 receptor agonist/sodium-glucose cotransporter-2 inhibitor (GLP-1RA/SGLT2i) therapy. Patients were censored at treatment change. Stabilized inverse probability of treatment weighting was used to balance baseline covariates. Weighted Cox models evaluated all-cause mortality, heart failure hospitalization, stroke, and repeat coronary revascularization. Results: Among 19,237 patients, 4,791 (24.9%) had no observed post-discharge diabetes therapy, 8,231 (42.8%) received metformin, 4,401 (22.9%) received insulin, and 1,814 (9.4%) received GLP-1RA/SGLT2i therapy. Compared with no treatment, all active therapies were associated with lower mortality: GLP-1RA/SGLT2i (hazard ratio [HR] 0.07, 95% CI 0.04-0.11), metformin (HR 0.21, 95% CI 0.18-0.24), and insulin (HR 0.14, 95% CI 0.11-0.17; all p<0.001). GLP-1RA/SGLT2i therapy was associated with lower mortality than metformin (HR 0.25, 95% CI 0.15-0.40; p<0.001), whereas mortality did not differ between GLP-1RA/SGLT2i and insulin or between metformin and insulin. GLP-1RA/SGLT2i and metformin were also associated with lower risks of heart failure hospitalization (HR 0.79, 95% CI 0.65-0.96; p=0.02 and HR 0.60, 95% CI 0.53-0.67; p<0.001) and stroke (HR 0.57, 95% CI 0.40-0.83; p<0.01 and HR 0.73, 95% CI 0.61-0.88; p<0.001) compared with no treatment. Repeat revascularization did not differ across groups. Conclusions: Nearly one-quarter of patients with type 2 DM had no observed post-discharge diabetes therapy after CABG. Active therapy was associated with lower mortality and selected cardiovascular outcomes, and GLP-1RA/SGLT2i therapy was associated with lower mortality compared with metformin. Initial diabetes therapy after CABG represents a modifiable opportunity for long-term secondary prevention among patients with type 2 DM.