Bilateral internal mammary artery grafting: In situ versus Y-graft. Similar 20-year outcome

Abstract

OBJECTIVE: The aim of this study was to evaluate the 20-year clinical outcome of patients undergoing coronary artery bypass grafting with bilateral internal mammary arteries (BIMAs) using two different configurations, in situ versus Y-graft. METHODS: From September 1991 to December 2002, 2150 patients with multivessel coronary artery disease underwent isolated myocardial revascularization with BIMA grafting. BIMA was used as an in situ or Y-configuration in 1332 and 818 cases, respectively. A propensity score model was applied to calculate a standardized difference of ≤10% between groups (BIMA in situ vs BIMA Y-graft), and a cohort of 1468 matched patients was identified (734 in each group). Death, non-fatal myocardial infarction and the need for repeat revascularization were defined as 'major adverse cardiac events'. RESULTS: Late mortality was 24.3% (n = 357) [BIMA in situ vs BIMA Y-graft: 26.9% (n = 197) vs 21.8% (n = 160)]; in 11.6% (n = 170) of cases death was due to cardiac causes [11.9% (n = 87) vs 11.3% (n = 83)]. The rate of major adverse cardiac events was 37.1% (n = 545) [40.8% (n = 299) vs 33.5% (n = 246)]. The 20-year survival was 59 ± 6% and the event-free survival was 45 ± 7%. CONCLUSIONS: The clinical outcome of BIMA grafting is independent of surgical configuration. Y-grafting increases the flexibility of BIMA grafting and should be taken into account when a surgical strategy for myocardial revascularization needs to be planned.