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.