Value of Internal Thoracic Artery Grafting to the Left Anterior Descending Coronary Artery at Coronary Reoperation

OBJECTIVES:

The study sought to determine if left internal thoracic artery (LITA) grafting of the left anterior descending (LAD) at reoperative coronary artery bypass grafting (CABG) improves patient outcomes.

BACKGROUND:

LITA grafting to the LAD is the gold standard for primary CABG, but its value for reoperative CABG is unknown.

METHODS:

From January 1985 to January 2007, reoperative CABG was performed in 3,473 patients who did not receive a LITA during their primary CABG and whose anterior myocardium (LAD) was at risk at reoperation: 2,389 had LITA grafting and 1,084 saphenous vein (SV) grafting to the LAD. Propensity matching (908 matched pairs) was used for balanced comparison of outcomes. Follow-up was continued to 20 years post-operatively, with a mean follow-up of 11 ± 8.2 years.

RESULTS:

Unadjusted hospital mortality was 2.2% and 6.5% in the LITA and SV groups, respectively (p < 0.001), but 3.1% and 5.6% in propensity-matched groups (p = 0.008). Unadjusted survival at 1, 5, 10, 15, and 20 years was 94%, 82%, 64%, 46%, and 32% for the LITA group, but 88%, 73%, 50%, 32%, and 18% for the SV group (p <.0001), respectively. For propensity-matched groups, both early (p = 0.01) and late survival was greater (p = 0.005) in the LITA group. At 20 years, LITA grafting of the LAD at reoperation resulted in an absolute mortality risk reduction of 6.0% and a hazard ratio of 0.85, with number needed to treat of 16 patients.

CONCLUSIONS:

LITA-to-LAD grafting at reoperation is safe and confers a risk-adjusted survival advantage. When appropriate, a LITA should be used to revascularize the LAD at coronary reoperations.