21-Year Survival of Left Internal Mammary Artery-Radial Artery-Y Graft

Background: In 1999, Royse et al. reported on the left internal mammary artery, radial artery, Y-graft technique (LIMA-RA-Y), which achieves total arterial revascularization (TAR). However, the most common coronary reconstruction remains LIMA and supplementary saphenous vein grafts (LIMA + SVG).

Objectives: The goal of this study was to conduct a survival comparison of LIMA-RA-Y versus the conventional LIMA + SVG.

Methods: Of the original 464 LIMA-RA-Y patients reported (1996 to 1998), 346 were from the Royal Melbourne Hospital. Survival at June 2017 was compared with a group of 534 patients from 1996 to 2003 from the same institution who received LIMA + SVG, or 5,800 patients who received TAR with different grafting configurations. Propensity score matching (PSM) was performed with 1:1 matching using 26 variables. Comparisons used Kaplan-Meier (KM) and Cox proportional hazards methods. LIMA-RA-Y was compared with LIMA + SVG in which all non-left anterior descending artery grafts were performed with either composite RA or aorta-coronary SVG with no use of right internal mammary artery. We also conducted a comparison of LIMA-RA-Y versus TAR.

Results: Baseline characteristics of the LIMA-RA-Y group (n = 346) compared with LIMA + SVG (n = 534) after PSM (n = 232 pairs) did not differ (3.3 ± 0.8 grafts per patient). Survival was worse for LIMA + SVG in the unmatched groups (KM, p < 0.001) and for PSM groups (KM, p = 0.043; Cox proportional hazards ratio: 1.3; 95% confidence interval: 1.0 to 1.6; p = 0.038). Survival did not differ between LIMA-RA-Y and other TAR (n = 5,800) patients before, or after, PSM (n = 332 pairs).

Conclusions: Use of LIMA + SVG has worse survival than LIMA-RA-Y in achieving total arterial revascularization.