Total Arterial Revascularization in Diabetic Patients Undergoing Coronary Artery Bypass Graft Surgery: A Systematic Review and Meta-Analysis

Background: Total arterial revascularization (TAR) has gradually become accepted and recognized, but its effect and safety in diabetic patients are not clear. We performed a systematic review and meta-analysis to summarize the safety and efficacy of TAR and addition-ally evaluated the clinical outcomes of arterial revascularization using different arterial deployments in patients with diabetes. Methods: PubMed, Embase, and the Cochrane Library databases from inception to July 2022 for studies that studied the effect of arterial revascular-ization in diabetic patients undergoing isolated coronary artery bypass graft (CABG) were searched. The primary outcome was long-term (& GE;12 months of follow-up) death by any cause. The secondary efficacy endpoints were long-term (& GE;12 months) cardiovascular death, early sternal wound infection (SWI) and death (& LE;30 days or in hospital). Risk ratios (RRs), hazard ratios (HRs), and their corresponding 95% confidence intervals (CIs) were calculated to describe short-term results and long-term survival outcomes. Two different ways were used to analyze the effect of TAR and the impact of diabetes on the clinical outcomes of TAR. Results: Thirty-five studies were included in the study, covering 178,274 diabetic patients. Compared to conventional surgery with saphenous veins, TAR was not associated with increased early mortality (RR 0.77, 95% CI 0.48-1.23) and risk of SWI (RR 0.77, 95% CI 0.46-1.28). The overall Kaplan-Meier sur-vival curves based on reconstructed patient data indicated a significant association between TAR and reduced late mortality (HR 0.52, 95% CI 0.48-0.67) and the curves based on the propensity-score matched (PSM) analyses suggested a similar result (HR 0.74, 95% CI 0.66-0.85). TAR could also effectively decrease the risk of cardiovascular death (HR 0.42, 95% CI 0.24-0.75). Through comparing the effect of TAR in patients with and without diabetes, we found that the presence of diabetes did not elevate the risk of early adverse events (death: RR 1.50, 95% CI 0.64-3.49; SWI: RR 2.52, 95% CI 0.91-7.00). Although diabetes increased long-term mortality (HR 1.06; 95% CI 1.35-2.03), the cardiovascular death rate was similar in patients with diabetes and patients without diabetes (HR 1.09; 95% CI 0.49-2.45). Regarding the selection of arterial conduits, grafting via the bilateral internal mammary artery (BIMA) decreased the risk of overall death (HR 0.67, 95% CI 0.52-0.85) and cardiovascular death (HR 0.55, 95% CI 0.35-0.87) without resulting in a significantly elevated rate of early death (RR 0.95, 95% CI 0.82-1.11). However, the evidence from PSM studies indicated no difference between the long-term mortality of the BIMA group and that of the single internal mammary arteries (SIMA) groups (HR 0.76, 95% CI 0.52-1.11), and the risk of SWI was significantly increased by BIMA in diabetes (RR 1.65, 95% CI 1.42-1.91). The sub-analysis indicated the consistent benefit of the radial artery (RA) application in diabetic patients (HR 0.71, 95% CI 0.63-0.79) compared to saphenous vein graft. In two propensity-score-matched studies, the evidence showed that the survival outcomes of the BIMA group were similar to that of the SIMA plus RA group but that grafting via the RA reduced the risk of sternal wound infection. Conclusions: Compared with con-ventional surgery using SVG, TAR was associated with an enhanced survival benefit in diabetes and this long-term gain did not increase the risk of early mortality or SWI. Given the increased infection risk and controversial long-term survival gains of grafting via the BIMA in diabetes, its wide use for grafting in this cohort should be seriously considered. Compared to using the right internal mammary artery (RIMA), RA might be a similarly effective but safer option for patients with diabetes.