OPTIMAL CONFIGURATION FOR BYPASS OF THE LAD DURING BILATERAL INTERNAL THORACIC ARTERY GRAFTING

Abstract

Coronary artery bypass graft (CABG) surgery is considered the most effective and durable approach to multi-vessel coronary revascularization primarily attributed to the excellent patency of the internal thoracic artery (ITA) to left anterior descending (LAD) artery graft. This success has led to the increased use of bilateral ITA (BITA). However, it is not clear whether the left ITA (LITA) or the right ITA (RITA) should be used for the LAD. Therefore, the objective of this study was to compare clinical outcomes between LITA-LAD and RITA-LAD configurations in BITA grafting. The primary outcome was the need for percutaneous or surgical re-intervention of the LAD territory. Secondary outcomes included all-cause mortality and cardiac mortality. Cox proportional hazard models were used with entropy weighting to balance groups. Competing risks were determined using the Fine and Gray model. The studied cohort included 1527 BITA patients with LITA-LAD and 523 with RITA-LAD. The median follow-up was greater in the LITA-LAD group (6.5 years IQR[2.7, 11.3] vs 5.5 years[2.4, 9.2], p < 0.001). Before entropy weighting, RITA-LAD patients were significantly older with more diabetes, peripheral vascular disease and left ventricular dysfunction and more urgent status (all with p < 0.05). Cases with RITA-LAD were also more frequently performed off-pump (p < 0.001). Predicted need for repeat revascularization of the LAD territory at 10 years was 2.8% in the LITA-LAD group and 1.8% in the RITA-LAD group. There was no difference in the need for LAD re-revascularization between groups (Subhazard HR [SHR] 0.686 95% CI [0.296, 1.589], p=0.38). There was no difference in long term all-cause mortality (HR 1.056 95%CI [0.677, 1.647], p=0.81). Adjusted survival at 10 years was 97.2% in the LITA-LAD group and 98.2% in the RITA-LAD group. There was no difference in the risk of cardiac death (SHR 1.062 95%CI [0.502, 2.250], p=0.87). The use of either the LITA or the RITA for LAD grafting during BITA revascularization has no effect on long-term cardiac and all-cause mortality or need for repeat revascularization of the LAD territory. Cardiac surgeons should be confident in using a RITA-LAD bypass in their operative strategy.View Large Image Figure ViewerDownload Hi-res image Download (PPT)