On-pump versus off-pump coronary artery bypass grafting for left main coronary artery disease: long-term outcomes

Previous studies comparing off-pump versus on-pump coronary artery bypass grafting (CABG) have shown inconsistent results, especially for left main coronary artery disease (LM CAD), largely due to variations in surgical expertise. This study evaluates outcomes from a high-volume center with considerable experience in both techniques.

We retrospectively analyzed 1,410 patients with significant LM CAD (stenosis ≥70% or functionally significant 50-69%) who underwent isolated CABG between 2003 and 2017. The primary endpoint was a composite of death, myocardial infarction (MI), or stroke within 5 years. Analyses included Cox regression, inverse probability of treatment weighting (IPTW), and propensity score (PS) matching with adjustments for surgeon type and temporal trends.

Of 1,410 patients, 824 underwent off-pump and 586 underwent on-pump CABG. The off-pump group demonstrated a low conversion rate (1.0%) and high left internal mammary artery (LIMA) utilization (97.0%). The 5-year composite endpoint (death, MI, or stroke) was similar between groups [14.7% for off-pump vs. 15.0% for on-pump; unadjusted hazard ratio (HR): 0.98, 95% confidence interval (CI): 0.74-1.30], and this finding persisted after adjustments for baseline differences. Individual components showed comparable rates of death and stroke, while in-hospital composite outcomes were lower in the off-pump group (1.3% vs. 3.5%; P=0.01).

Our findings suggest that in a high-volume center with experienced surgeons, off-pump CABG for LM CAD can achieve long-term outcomes comparable to on-pump CABG. Larger prospective studies are warranted to confirm these findings and establish optimal patient selection criteria.