Impact of Prior Myocardial Infarction on Outcomes Following Multiple Arterial Coronary Bypass Grafting: A Propensity-Matched Analysis

Background: Multiple arterial grafting (MAG) is associated with superior long-term outcomes in coronary artery bypass grafting (CABG). The influence of prior myocardial infarction (MI) on outcomes following MAG remains uncertain. This study evaluates in-hospital outcomes and long-term survival of MAG in patients with and without previous MI. Methods: A retrospective single-center observational analysis of 2468 patients undergoing MAG was performed. Propensity score matching yielded 911 pairs based on preoperative variables. Kaplan–Meier survival analysis and Cox regression were used to assess long-term survival and predictors of mortality. Results: In the unmatched cohort, patients with prior MI had significantly higher rates of diabetes (30.6% vs. 23.9%, p < 0.001), smoking history (p < 0.001), and impaired left ventricular function (fair/poor LVEF: 32.4% vs. 11.1%, p < 0.001), along with higher logistic EuroSCORE (3.81 vs. 3.11, p < 0.001). After matching, baseline characteristics were balanced. In-hospital outcomes, including 30-day mortality (1.5% vs. 1.9%, p = 0.587), stroke, reoperation, and renal complications, were similar. Long-term survival at 10, 15, and 20 years was comparable (log-rank p = 0.814). Multivariate Cox regression identified age (HR 1.065, p < 0.001), NYHA class, diabetes (HR 0.779, p = 0.008), and off-pump CABG (HR 1.444, p < 0.001) as independent predictors of mortality. Prior MI was not associated with increased long-term mortality (HR 0.872, p = 0.105). Conclusions: Despite worse baseline risk profiles, patients with prior MI undergoing MAG had equivalent in-hospital outcomes and long-term survival. MAG remains a robust revascularization strategy irrespective of MI history, supporting its broader use in CABG. These findings should be interpreted in the context of a single-center experience from a high-volume arterial grafting program.