NEW YORK (Reuters Health) – Among patients undergoing their first coronary artery bypass procedure, outcomes are better when saphenous vein grafts are used for a single distal anastomosis rather than for multiple target vessels, according to a new study.

“These data should encourage the use of s-SVG (saphenous vein grafts with single distal targets) over m-SVG (saphenous vein grafts with multiple distal targets) when feasible,” the authors advise in the July 19 issue of Circulation.

Dr. Rajendra H. Mehta, with the Duke Clinical Research Institute in Durham, North Carolina, and colleagues point out that grafts with multiple distal targets are often used in CABG surgery when saphenous vein material is limited. Also, because only one proximal anastomosis is involved, such procedures are shorter than placing several single saphenous vein grafts.

However, studies of outcomes of saphenous vein grafts with multiple distal targets (m-SVG) versus saphenous vein grafts with single distal targets (s-SVG) are dated. The team therefore looked at data from a recent SVG failure prevention trial in which 1045 patients had at least one m-SVG during CABG and 1969 had s-SVGs only.

“Saphenous vein graft failure was lowest in patients with isolated s-SVG (41.6%), highest in those with isolated m-SVG (50.6%), and intermediate in those with m- and s-SVG (46.0%),” the researchers found. This translated to an odds ratio of 1.24 for graft failure at 1 year for m-SVG compared to s-SVG.

Over the longer term, the risk of major adverse cardiac events at 5 years was significantly higher with use of m-SVGs. Specifically, the hazard ratio for the adjusted composite endpoint of death, MI, or revascularization was 1.15, according to the report.

“These findings should stimulate further studies to identify why m-SVGs have a higher failure rate and to better understand the most appropriate conduit to improve long-term graft patency and clinical outcomes of patients undergoing CABG surgery,” Dr. Mehta and colleagues conclude.

Circulation 2011;124.