Arterial grafts protect the native coronary vessels from atherosclerotic disease progression.

BACKGROUND We sought to examine the effect of different conduits on the progression of atherosclerosis in previously revascularized coronary territories. METHODS Between 1995 and 2010, 4,960 patients were discharged alive after primary isolated coronary artery bypass grafting (CABG) with a left internal thoracic artery (LITA) conduit and additional conduits as needed: radial artery (RA) or saphenous vein graft (SVG), or both. Seven hundred seventy-two patients had coronary angiography for recurrent symptoms an average of 5.5±3.5 years after CABG (range, 0.1-16 years). Cumulative graft patency and disease progression in the native vessels was estimated by the Kaplan-Meier survival method. The log-rank test was used to assess differences of disease progression per territory between different types of conduits. RESULTS Kaplan-Meier-estimated 1-, 5-, and 10-year overall disease progression in territories with patent LITAs was 0.01%, 4%, and 8%, respectively; with patent RA grafts, it was 0.01%, 6%, and 11%, respectively (log-rank test, p=0.157); and with patent SVGs it was 3%, 19%, and 43%, respectively (log-rank test; p<0.0001). Disease progression in grafted native coronary arteries in the anterior territory with patent LITA-to-left anterior descending (LAD) artery was 8%, and with patent RA grafts versus patent SVGs to the diagonal branches of LAD artery was 10% and 40%, respectively (log-rank test; p<0.0001). Disease progression in grafted native coronary arteries to the lateral territory with a patent RA graft was 11% versus 50% with a patent SVG (log-rank test; p<0.0001). CONCLUSIONS RA and LITA grafting has a strong protective effect against progression of native coronary artery disease in previously grafted vessels. Multiple arterial grafting may improve long-term survival by preventing progression of atherosclerosis in the native coronary vessels.