No improvements in long-term outcome after coronary artery bypass grafting with arterial grafts as a second conduit: A Swedish nationwide registry study

Abstract

OBJECTIVES: Coronary artery bypass grafting using saphenous vein grafts (SVGs) in addition to the left internal mammary artery (IMA) graft is vitiated by poor long-term patency of the vein grafts. Hypothetically, the increased use of arterial grafts could confer even better outcomes. Our goal was to evaluate results after coronary artery bypass grafting in Sweden, where arterial grafts were used as a second conduit. METHODS: Within the Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies (SWEDEHEART) registry, we identified patients who had coronary artery bypass grafting from 2001 to 2015 using the IMA and the SVG, the radial artery (RA) or the additional IMA [bilateral IMA (BIMA)] as a second conduit. Deaths, postoperative incidence of coronary angiography and need for reintervention were recorded, and multivariable adjusted hazard ratios were calculated for different types of grafts. RESULTS: The study population comprised 46 343 cases of IMA + SVG, 1036 cases of IMA + RA and 862 cases of BIMA. The mean followup time (SD) was 9.3 (4.2) years for IMA + SVG, 10.7 (4.1) years for IMA + RA grafts and 5.5 (5.0) years for the BIMA graft. The adjusted hazard ratio for death was (95% confidence interval) 1.01 (0.89-1.14) for IMA + RA and 0.87 (0.72-1.06) for BIMA grafts compared with IMA + SVG. The adjusted hazard ratio for the first angiographic examination was (95% confidence interval) 0.96 (0.84-1.10) for IMA + RA and 1.13 (0.95-1.35) for BIMA grafts. The adjusted hazard ratio for the need for reintervention was (95% confidence interval) 0.91 (0.75-1.09) for IMA + RA and 1.26 (1.00-1.58) for BIMA grafts. CONCLUSIONS: Patients who had arterial grafts as second conduits did not demonstrate a better outcome in any of the studied endpoints. Radial artery grafts seem to be preferable to BIMA grafts as an alternative to an SVG.