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

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