Bilateral Versus Single Internal Mammary Artery Bypass Grafting

Article, see p 1676 The article by Iribarne et al1 in this issue of Circulation describes a retrospective study comparing the long-term outcome of propensity-matched groups of patients undergoing either bilateral (BIMA) or single (SIMA) internal mammary artery coronary artery bypass grafting (CABG), with emphasis on the need for repeat revascularization. The study originated from the Northern New England Cardiovascular Disease Study Group, which has been a leader in examining outcomes after cardiovascular surgery and quality improvement.CABG has continued to be a principal method to treat advanced coronary disease. With improved percutaneous coronary intervention and medical treatment, CABG has been forced to improve as well. The SIMA graft was first introduced by Loop et al2 to significantly prolong survival and to improve the outcome of CABG. The use of 2 internal mammary artery grafts (BIMA) was described by Suzuki et al3 in 1973. It would make sense that if the SIMA were good, BIMA would be better. Indeed, Lytle et al4 reported from the Cleveland Clinic that patients who received CABG with BIMA grafts did better than if they received a SIMA graft. Since this publication, many studies have demonstrated what seems to be common sense, that patients who receive BIMA grafts5,6 or multiple arterial grafts of other types should do much better in the long …