Impact of coronary artery bypass grafting on survival after aortic valve replacement.

Treatment of coronary artery disease by coronary artery bypass grafting (CABG) concurrently with aortic valve replacement (AVR) improves outcome but survival compared to isolated AVR remains uncertain, as does the role of the left internal mammary artery (LIMA) graft to the left anterior descending (LAD) artery. All 799 patients undergoing elective primary AVR, using the St. Jude Medical mechanical prosthesis, with or without CABG, between March 1986 and May 2000, were reviewed with 100% follow-up. Operative mortality was 1.6% in 574 patients undergoing isolated AVR, 2.6% in 78 patients undergoing combined AVR and CABG with LIMA to LAD grafting (LIMA-AVR), 6.25% in 64 patients receiving vein grafts only to circumflex or right coronary artery territories (Non-LAD VG-AVR) and 2.4% in 83 patients receiving vein grafts to vessels including the LAD (LAD VG-AVR). Cox regression analysis showed improved survival after AVR compared to LAD VG-AVR (P=0.008), but with no significant difference to survival after LIMA-AVR (P=0.18) and Non-LAD VG-AVR (P=0.08). Multivariable regression analysis identified advanced age (P<0.001), male sex (P<0.001), absence of diabetes (P=0.02), number of grafts performed during surgery (P=0.04), non-congenital valvular pathology (P=0.001) and regurgitant valve disease (P=0.008) as independent predictors of reduced survival. LIMA-LAD grafting was not a significant variable in the multivariable model.