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. (J Am Coll Cardiol 2013;61:302-10) (C) 2013 by the American College of Cardiology Foundation