Bilateral internal thoracic artery on the left side: a propensity score-matched study of impact of the third conduit on the right side.

OBJECTIVE: This study was undertaken to evaluate long-term results of bilateral internal thoracic artery grafting with saphenous vein or another arterial conduit as the third conduit.

METHODS: From September 1991 to December 2002, a total of 1015 patients underwent first isolated coronary artery bypass grafting for triple-vessel disease, with bilateral internal thoracic artery plus saphenous vein in 643 cases and bilateral internal thoracic artery plus arterial conduit in 372. A nonparsimonious regression model was built to determine propensity score, then sample matching (saphenous vein vs arterial conduit) was performed to select 885 patients (590 with saphenous vein, 295 with arterial conduit). Groups had similar preoperative and operative characteristics.

RESULTS: Eight-year freedoms from cardiac death were significantly higher when saphenous vein was used (98.6% +/- 0.5% with saphenous vein vs 95.3% +/- 1.3% with arterial conduit, P = .009), but this difference was related exclusively to right gastroepiploic artery grafting (94.5% +/- 1.6% vs saphenous vein, P = .004). This difference disappeared for radial artery grafting (97.6% +/- 1.6% vs saphenous vein, P = .492). Cox analysis confirmed that supplementary gastroepiploic artery was an independent variable for lower freedoms from all-cause mortality and from cardiac death. Presence of high-degree stenosis (80%) appeared to influence this result.

CONCLUSIONS: In patients with triple-vessel disease undergoing first isolated coronary artery bypass grafting, supplementary venous grafts seem to provide more stability than gastroepiploic artery, which may even impair long-term outcome.