Very Long-term Outcome of Bilateral Internal Thoracic Artery in Diabetic Patients: A Systematic Review and Reconstructed Time-To-Event Meta-analysis

The benefits of single (SITA) and bilateral internal thoracic arteries (BITA) in diabetics undergoing coronary bypass grafting (CABG) are conflicting. We undertook a study-level meta-analysis to compare early and long-term outcomes of both CABG configurations. PubMed, CENTRAL, and EMBASE were searched for studies comparing BITA versus SITA for isolated CABG surgery in diabetics. Randomized trials or observational studies were considered eligible for the analysis. Kaplan-Meier curves of long-term survival were reconstructed and compared with Cox linear regression; incidence rate ratios (IRR) with 95% confidence intervals (CI) for long-term survival were calculated. Landmark analysis and time-varying hazard ratio (HR) were analyzed. Odds ratios (OR) were extracted for early mortality, postoperative stroke, deep sternal wound infection (DSWI), and myocardial infarction (MI). A random effects meta-analysis was performed. Sensitivity analyses included leave-one-out-analyses and meta-regression. Thirteen studies (7332 patients) were included. Overall, at 20-year follow-up, BITA was associated with higher survival (HR = 0.77; 95% CI, 0.71-0.84; P < 0.0001). Time-varying HR and landmark analysis reported BITA was associated with a higher rate of 10-year survival (HR = 0.75, 95% CI 0.68-0.82, P < 0.0001), while from 10 to 20-year follow-up no difference was revealed (HR = 0.99, 95% CI 0.82-1.19, P = 0.93). There was no increase in early mortality, postoperative MI, stroke, or DSWI between the groups. At meta-regression, the higher the age, the higher the long-term overall survival in patients with BITA. In diabetics, the BITA approach is associated with improved 10-year survival with no increase in early mortality, MI, stroke, or DSWI. In the 10-20-year timeframe, BITA and SITA showed comparable survival.