IN-HOSPITAL AND LONG-TERM CLINICAL OUTCOMES OF CORONARY ARTERY BYPASS GRAFTING USING THE RADIAL ARTERY: SUPERIOR SURVIVAL

Abstract

Recent studies suggest the radial artery is associated with superior long-term patency than the saphenous vein in coronary artery bypass graft (CABG) surgery. However, literature evaluating clinical, rather than angiographic, outcomes comparing the conduits is currently less extensive. Our objective was to examine in-hospital and long-term clinical outcomes for patients who have undergone CABG surgery using the left internal mammary artery (LIMA) and the radial artery, compared to those using the LIMA and the saphenous vein. This single-centre retrospective observational study evaluated in-hospital and long-term follow-up for consecutive patients undergoing isolated non-redo CABG procedures at the Queen Elizabeth II Health Sciences Centre in Halifax, Nova Scotia from September 1st, 1998 to December 31st, 2004. In-hospital post-operative outcomes included: mortality, stroke, deep sternal wound infection, sepsis, blood transfusion, MI, length of ICU stay, length of hospital stay, ventilation time, and re-operation. Long-term follow-up data was obtained from the Canadian Institute for Health Information and Vital Statistics. Cox proportional hazards analysis was used to examine long-term outcomes, including survival and freedom from hospital readmission for acute coronary syndrome or cardiovascular re-intervention. There were 4,886 consecutive cases, of which 1,076 used a radial artery graft and 3,810 did not. A propensity score model was developed to create 1,058 matched pairs. There were no statistically significant differences between the radial and non-radial groups with respect to in-hospital post-operative outcomes, aside from length of hospital stay, which was longer for radial patients (p=0.02). There were 4,474 surviving patients for whom long-term follow-up was available. Median follow-up was 9.80 (interquartile range (IQR), 4.35 to 11.71) years for the radial group and 8.64 (IQR, 3.56 to 10.51) for the non-radial group. After adjustment for comorbidities and acuity, there was no statistically significant difference between the groups in readmission for acute coronary syndrome or re-intervention. However, the radial artery group had superior long-term survival (78.2% [95% confidence interval (CI), 76.0 to 80.5] versus 66.4% [95% CI, 64.9 to 68.0]) at 10 years. This difference remained significant in multivariate analysis (hazard ratio, 0.85 [95% CI, 0.74 to 0.97; p=0.016]). Use of the radial artery in CABG surgery was associated with better long-term survival compared to the saphenous vein. There were no significant differences in long-term freedom from cardiac readmission. The results of this study suggest the radial artery and the LIMA may be preferable to the saphenous vein and the LIMA in isolated CABG procedures.