Operative Outcomes of Multiple-Arterial Versus Single-Arterial Coronary Bypass Grafting

Abstract

Background: More than 90% of coronary artery bypass grafting (CABG) is performed with a single-arterial bypass graft (SABG), based on the left internal thoracic artery (ITA) with supplemental vein grafts. This practice, often justified by safety concerns with multiple-arterial grafting (MABG), defies evidence of improved late survival achieved with bilateral ITA (BITA-MABG) or left ITA plus radial artery (RA-MABG). We hypothesized that MABG and SABG are equally safe.

Methods: We analyzed The Society of Thoracic Surgeons National Database (2004 to 2015) to assess the operative safety of BITA-MABG (n = 73,054) and RA-MABG (n = 97,623) vs SABG (n = 1,334,511). Primary end points were operative (30-day or same hospitalization) mortality (OM) and deep sternal wound infections (DSWI). Risk-adjusted odds ratios (AOR) and 95% confidence intervals (CIs) were derived from by logistic regression with sensitivity analyses in multiple subcohorts including MABG use rate.

Results: SABG (73.8% men; median age, 66 years), BITA-MABG (85.1% men; median age, 59 years), and RA-MABG (82.5% men; median age, 61 years) showed distinctly different patient characteristics. Compared with SABG (1.91% OM; 0.73% DSWI), observed OM was lower for BITA-MABG (1.19%, p < 0.001) and RA-MABG (1.19%, p < 0.001). DSWI was higher among BITA-MABG (1.08%, p < 0.001) and similar for RA-MABG (0.71%, p = 0.55). BITA-MABG showed marginally increased, likely not clinically significant, OM (AOR, 1.14; 95% CI, 1.00 to 1.30; p = 0.05) and doubled DSWI (AOR, 2.09; 95% CI, 1.80 to 2.43; p < 0.001). RA-MABG had similar OM (AOR, 1.01; 95% CI, 0.89 to 1.15; p = 0.85) and DSWI (AOR, 0.97; 95% CI, 0.83 to 1.13; p = 0.70). Results were consistent across multiple subcohorts. A U-shaped OM vs BITA use relation was documented, with worse OM at hospitals with low (<5%: AOR, 1.38; 95% CI, 1.18 to 1.61; p < 0.001) and high (≥40%: AOR, 1.31; 95% CI, 1.00 to 1.70; p = 0.049) BITA use.

Conclusions: MABG in the United States is associated with OM comparable to SABG and increased DSWI risk with BITA-MABG. Our findings highlight the importance of surgeon and institutional experience and careful patient selection for BITA-MABG. Our short-term results should not in any way dissuade the use of MABG, given its well-established long-term survival advantage.