Multiarterial grafting in redo coronary artery bypass grafting: Type of arterial conduit and patient sex determine benefit.

Objective: To evaluate whether multiarterial grafting provides an incremental benefit above single arterial grafting in isolated redo coronary artery bypass grafting (CABG).

Methods: From January 1980 to July 2020, 6559 adults underwent a total of 6693 isolated CABG reoperations. Patients undergoing multiarterial grafting were propensity score-matched with those undergoing single arterial grafting with or without additional vein grafts, yielding 2005 well-matched pairs. Endpoints were in-hospital postoperative complications, hospital mortality, and long-term mortality. The median follow-up was 10 years, with 25% of patients followed for >17 years. Multivariable multiphase hazard models and nonparametric random survival forest models for survival were used to identify patients for whom multiarterial grafting was most beneficial.

Results: Among propensity score-matched patients, postoperative complications in multiarterial versus single arterial grafting included any reoperation (50 [2.5%] vs 65 [3.2%]); renal failure (73 [3.6%] vs 55 [2.7%]), stroke (44 [2.2%] vs 38 [1.9%]), and deep sternal infection (36 [1.8%] vs 25 [1.2%]). In-hospital mortality was 1.7% (n = 35) in multiarterial grafting versus 2.8% (n = 56) in single arterial grafting (P = .03). Comparing multiarterial to single arterial grafting, overall survival was 95% versus 94% at 1 year, 92% versus 88% at 3 years, 87% versus 82% at 5 years, 49% versus 42% at 15 years, and 31% versus 25% at 20 years. Better survival after multiarterial grafting was confined to males with 2 patent internal thoracic artery grafts (P < .0001).

Conclusions: Redo CABG with multiarterial grafting can be performed with lower in-hospital mortality and similar major morbidity to single arterial grafting. It is associated with better long-term survival, particularly in males when 2 internal thoracic artery grafts are used.