Right Internal Thoracic Artery Patency Is Affected More by Target Choice Than Conduit Configuration.

Abstract

BACKGROUND\nAlthough coronary artery bypass grafting using bilateral internal thoracic arteries (BITA) maximizes long-term survival, knowledge of the effect of different right ITA (RITA) inflow configurations on graft patency is limited. We have compared RITA occlusion among these configurations and identified its risk factors while adjusting for outflow coronary target location.\n\n\nMETHODS\nFrom 1/1972-1/2016, of 7,092 patients undergoing BITA grafting at a single center, 1,331 received 1 ITA to the left anterior descending coronary artery (LAD) and had ≥1 evaluable postoperative coronary angiograms: 835 (63%) in-situ, 496 free-RITA grafts (311 [63%] originating from aorta, 98 [20%] left internal thoracic artery (LITA), 76 [15%] saphenous vein graft [SVG], 11 [2%] radial graft). RITA occlusion reported on 1,983 angiograms performed a median of 5.8 years later was estimated using nonlinear mixed-effects longitudinal modeling.\n\n\nRESULTS\nRITA patency was 90% at 1 year, 87% at 5 years, and 86% at 10 and 15 years. At 15 years, in-situ RITA patency was 91% and free RITA patency from aorta 91%, LITA 89%, and SVG 77%. After adjusting for coronary target location and degree of stenosis, occlusion was similar in free RITAs from aorta (P=.15), LITA (P=.4), SVG (P=.13), and in-situ RITAs. However, RITAs grafted to the LAD had fewer occlusions (P<.001), with patency similar to LITAs.\n\n\nCONCLUSIONS\nAmong patients with BITA grafting requiring interval coronary angiography, long-term RITA patency was high and independent of its inflow configuration. Therefore, priority should be a RITA configuration optimizing its reach to important coronary targets, including the LAD.