Robot-Assisted Minimally Invasive Direct Coronary Artery Bypass Graft in High-Risk Patients with Reduced Left Ventricular Function: Comparison with Conventional Off-Pump Coronary Artery Bypass Graft Surgery

Objective: Robotic-assisted minimally invasive direct coronary artery bypass (RA-MIDCAB) is a proven alternative to conventional off-pump sternotomy for revascularizing the left anterior descending artery (LAD) in low-risk patients. However, its role in higher-risk candidates remains poorly established. This study compares RA-MIDCAB with off-pump CABG (OPCAB) in intermediate/high-risk patients with moderately reduced left ventricular ejection fraction (LVEF). Methods: We retrospectively analyzed all consecutive high/intermediate-risk patients with depressed LVEF who underwent left internal mammary artery to LAD RA-MIDCAB or OPCAB at our center between January 2021 and August 2025. The primary outcome, assessed at discharge and follow-up, was a composite of all-cause mortality, stroke, and repeat revascularization. Secondary outcomes included ICU stay, red blood cells (RBC) transfusion volume, oro-tracheal intubation time, and acute kidney injury. Kaplan–Meier curves estimated the cumulative freedom from the primary outcome. Restricted mean survival time (RMST) at 1 year was calculated, with non-inferiority confirmed if the lower bound of the 95% CI exceeded − 8 days. A generalized linear model adjusted for confounders. Results: Seventy-two patients were included: 20 RA-MIDCAB and 52 OPCAB. EuroSCORE was 3.8 ± 1.9 and 3.5 ± 2.4 in RA-MIDCAB and OPCAB, respectively (p = 0.384), while mean LVEF was 40 ± 13 and 45 ± 9, respectively (p = 0.454). Other variables were comparable; however, RA-MIDCAB patients had higher rates of prior myocardial infarction (MI) (45% vs. 11.5%; p = 0.003) and PCI (40% vs. 13.4%; p = 0.022). Procedural time was longer for RA-MIDCAB (196 ± 66 vs. 182 ± 66 min; p = 0.048). Thirty-day mortality was comparable (0% RA-MIDCAB, 3.8% OPCAB; p = 0.374), while ICU stay and intubation time were shorter in the RA-MIDCAB group. Fewer RA-MIDCAB patients required >5 RBC units. At one year, freedom from the primary outcome was 95% vs. 83.6% (p = 0.2), with RMST favoring RA-MIDCAB by 34.6 days (p = 0.0067), meeting the non-inferiority threshold. Results remained consistent after adjustment. Conclusions: RA-MIDCAB is noninferior to OPCAB in intermediate- to high-risk patients with moderately depressed LVEF, offering a valuable alternative to conventional surgical revascularization. These findings need further confirm through the analysis of larger datasets and longer follow-up.