Projected Long-Term Benefits of Coronary Artery Bypass Graft Surgery in Patients with Ischemic Cardiomyopathy

BACKGROUND Coronary artery bypass graft (CABG) decision-making in ischemic cardiomyopathy remains complex given trade-offs between surgical risk and long-term benefits. We investigated heterogeneity in absolute benefits of adding CABG to guideline-directed medical therapy (GDMT) using Surgical Treatment for Ischemic Cardiomyopathy trial data through long-term microsimulations. METHODS We performed microsimulations of 1212 trial participants randomized to GDMT plus CABG (N=610) or GDMT alone (N=602) with a state-transition model. We used multivariable Cox regression for individual-level heart failure readmission, CABG crossover, and mortality rates. We assessed heterogeneity in predicted differences of 20-year restricted mean survival time and 10-year cumulative event risks by baseline patient characteristics and 120-day mortality risk. Finally, we performed a scenario analysis with updated GDMT strategies. RESULTS Adding CABG improved restricted mean survival time by 1.4 years (95% uncertainty interval: 0.3-2.0), 10-year mortality by 6.0% (1.2-11.2%), and 10-year heart failure readmission risk by 7.6% (2.6-12.8%). With GDMT alone, 18.9% participants (15.8-21.8%) crossed over to CABG. Restricted mean survival time gains with CABG persisted for age ≥75 (+1.04 years) and operative mortality ≥12.5% (+0.79 years). Absolute heart failure readmission risk reduction was 8.0% for age <45 vs 8.8% for age ≥75, and 5.8% for low vs 10.0% for high operative mortality. Although CABG benefits decreased on average, they remained present with updated GDMT strategies. CONCLUSIONS Absolute benefits of CABG across survival and heart failure readmission remain significant in high-risk ischemic cardiomyopathy patients, even in the context of novel GDMT. Future randomized trials should be conducted to confirm these simulations.