Minimally Invasive Coronary Artery Bypass Grafting in Patients With Prior Myocardial Infarction: A Propensity Score-Matched Retrospective Study

Background: Patients with prior myocardial infarction (MI) represent a high-risk subgroup for coronary artery bypass grafting (CABG). The primary goal of CABG is durable myocardial revascularization to prevent recurrent ischemic events and improve survival. Minimally invasive CABG (MICS-CABG) may accelerate recovery, but evidence specifically in patients with a history of MI remains limited. Methods: We performed a single-center retrospective cohort study of adults with prior MI who underwent isolated CABG from 2017 to 2024. Patients with new or recurrent MI within 3 months were excluded. Patients underwent either MICS-CABG via left mini-thoracotomy or conventional CABG via median sternotomy. Propensity score matching (PSM; 1:1) was used to balance preoperative covariates. The primary outcome was the occurrence of major adverse cardiovascular events (MACEs) during the index hospitalization, reflecting the safety and adequacy of surgical myocardial revascularization. Secondary outcomes included postoperative length of stay (LOS), intensive care unit stay, 24-hour drainage volume, and in-hospital mortality. Univariable and multivariable linear regression analyses were performed to evaluate factors associated with postoperative LOS. Results: The unmatched cohort included 208 patients (sternotomy CABG, n = 142; MICS-CABG, n = 66). After PSM, 106 patients (53 pairs) were included in the analysis. The number of grafts was lower in the MICS-CABG group both before matching (1.71 ± 0.84 vs. 2.08 ± 0.91; p = 0.004) and after matching (1.79 ± 0.86 vs. 2.17 ± 0.89; p = 0.029). The number of diseased vessels was also lower in the MICS-CABG group after matching (1.83 ± 0.85 vs. 2.17 ± 0.83; p = 0.039). The incidence of in-hospital MACEs was low and did not differ between groups, and no MACEs occurred after matching. Postoperative LOS was shorter with the minimally invasive approach before matching (6.06 ± 2.79 vs. 7.20 ± 2.98 days; mean difference, −1.14 days; 95% confidence interval (CI), −1.97 to −0.31; p = 0.009) and after matching (6.09 ± 2.96 vs. 7.34 ± 2.68 days; mean difference, −1.25 days; 95% CI, −2.32 to −0.18; p = 0.025). However, this association was attenuated and no longer significant after multivariable adjustment. Early postoperative complications, support therapies, and in-hospital mortality were uncommon and comparable between groups, and no reoperations occurred. Conclusions: In selected patients with prior MI, MICS-CABG demonstrated comparable early safety and a similar incidence of in-hospital MACEs compared with conventional sternotomy CABG after PSM. Although the diseased/transplanted vessel ratio was similar between groups, this finding should be interpreted cautiously because the metric does not fully capture angiographic complexity or graftability. Although the minimally invasive approach was associated with a shorter postoperative LOS in unadjusted analyses, this association was attenuated and not statistically significant after multivariable adjustment.