Mid-term graft patency of right versus left internal mammary artery as arterial conduit usage for left anterior descending artery revascularisation: Insights from a single-centre study of propensity-matched data.

BACKGROUND: Previous studies reported the strategy of in situ skeletonised right internal mammary artery (RIMA) grafting to the left anterior descending artery (LAD). However, few reports have focused on assessing RIMA graft patency rate after grafting to the LAD. This study aimed to assess mid-term graft patency of in situ skeletonised RIMA grafting to the LAD versus in situ skeletonised left internal mammary artery (LIMA) grafting to the LAD in a single-centre propensity-matched study.

MATERIALS AND METHODS: After propensity score matching, 185 pairs of patients who received first, scheduled, isolated off-pump coronary artery bypass grafting (OPCAB) surgery were assigned to either a RIMA group (patients who received retrosternal crossover in situ skeletonised RIMA-LAD grafting with additional conduits grafting) or a LIMA group (patients who received in situ skeletonised LIMA-LAD grafting with additional conduits grafting). The primary endpoint was mid-term internal mammary artery (IMA) graft failure after grafting to the LAD and was determined by coronary computed tomography angiography examination. The secondary endpoints were mid-term all-cause mortality and the composite mid-term clinical outcome.

RESULTS: The graft patency rate of in situ skeletonised RIMA-LAD graft was not inferior to in situ skeletonised LIMA-LAD graft during a follow-up period of 36.6 ± 12.1 months (97.2% vs. 96.6%, p = 0.752). Kaplan-Meier curves showed a similar cumulative IMA graft failure between the two groups (χ2  = 0.092, Log-rank p = 0.762). And Cox regression analysis revealed that grouping was not an independent factor for follow-up IMA graft failure after grafting to the LAD (HR = 0.93, 95% CI: 0.68-2.13). Additionally, Kaplan-Meier curves showed similar cumulative survival free from adverse events between the two groups (χ2  = 2.365, p = 0.124, respectively).

CONCLUSIONS: Revascularisation of the LAD using a skeletonised RIMA resulted in excellent mid-term graft patency and clinical outcomes.