Current trends in bilateral internal thoracic artery use for coronary revascularization: Extending benefit to high-risk patients

Background: We sought to identify the trends in bilateral internal thoracic artery use and determine the degree to which the survival advantage of bilateral internal thoracic artery revascularization persists among perceived “high-risk” patients, compared with the use of left internal thoracic artery alone. Methods: A retrospective review was conducted of patients who underwent isolated coronary artery bypass grafting for multivessel coronary artery disease at the Mayo Clinic between January 2000 and December 2015. Propensity score matching was performed between patients with bilateral internal thoracic artery and left internal thoracic artery alone grafts (1011 matched pairs). Effect of bilateral internal thoracic artery use on survival in “high-risk” patients (ejection fraction <40%, body mass index ≥30, age ≥70 years, diabetes, chronic lung disease, cerebrovascular accident) was evaluated. Results: A total of 6468 isolated coronary artery bypass grafts were performed (5431 using left internal thoracic artery alone, 1037 using bilateral internal thoracic artery). There was an increasing trend in bilateral internal thoracic artery use (P value for linear trend =.005), with the percentage of coronary artery bypass grafting cases with bilateral internal thoracic artery doubling over the last 4 years (13% in 2012 to 27% in 2015). Propensity-matched comparisons showed a survival advantage for bilateral internal thoracic artery (hazard ratio, 0.81; 95% confidence interval, 0.66-0.99; P =.043). Risk of deep sternal wound infection, although higher in the bilateral internal thoracic artery group, was not significant (1.2% vs 0.5%; P =.088). None of the “high-risk” subsets of patients showed an adverse effect of bilateral internal thoracic artery on survival. Conclusions: Bilateral internal thoracic artery use in coronary artery bypass grafting is increasing over time. There is a consistent survival benefit with bilateral internal thoracic artery use, extending to patients with higher-risk comorbidities, suggesting the need for further expansion in use of this technique.