Should Bilateral Internal Thoracic Artery Grafting be Used in Patients with Left Main Disease?

Objectives: Left main diseas(LM) is a severe form of coronary artery disease .CABG is the standard of care for (LM) patients with complex lesions. Improved survival of patients treated with internal thoracic artery (ITA) grafts used to bypass the LAD artery is believed to be related to their better long-term patency compared to SVGs. Survival is further improved when two ITAs are used The purpose of this study is to compare outcome of bilateral ITA(BITA) grafting to that of single ITA and other conduits such as SVG and RA in patients LM.

Methods: Eight hundreds and thirty eight Patients with LM who underwent BITA grafting between 1996 and 2010 were compared with 408 LM patients who underwent CABG with SITA and SVG or RA.

Results: Patients undergoing SITA were older, more often female, more likely to have chronic obstructive lung disease, EF,30% ,Diabetes, renal insufficiency, peripheral vascular disease and emergency operation. Euroscore of SITA patients was significantly higher(8.87 +4.46 vs. 6.12 + 3.67 p<0.001)

operative mortality (2.3% vs. 5.1% in BITA and SITA)and sternal wound infections (2.3% vs. 2.0%) were not significantly different between groups.

Median follow-up was 12.8 (95%CI 11.98-13.61) years. Ten-year survival (Kaplan-Meier ) of the SITA group was significantly lower than that of the BITA group (50.1+2.8% vs. 69.2+1.7%, P <0.001, Log Rank test) .However, assignment to the BITA group was not associated with better propensity-adjusted survival (HR 0.958, 95% CI: 0.822-1.118, P =0.588) (COX model. )

Conclusions: This large cohort study shows. that, early and long-term outcomes of BITA grafting are not better than those of patients treated with SITA. Early mortality from non-cardiac causes ,reduces the influence of the type of conduit used(BITA or SITA) on survival. Selective use of BITA in lower-risk left main patients might un-mask the benefits of BITA grafting