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.