Ten-Year Outcomes of CABG With BITA Grafts Favorable in Patients With Diabetes

Long-term outcomes of off-pump coronary artery bypass graft (CABG) with bilateral internal thoracic artery (BITA) grafts are favorable and similar between the general population and patients with diabetes mellitus (DM), according to results of a study published in Cardiovascular Diabetology.

Patient records from Samsung Medical Center in South Korea were reviewed for this study. Patients (N=3395) who received off-pump CABG with BITA grafts between 2001 and 2017 were evaluated for outcomes up to 10 years on the basis of DM status. Major adverse cardiovascular events (MACE) were defined as the composite of cardiac death, myocardial infarction (MI), and revascularization.

The DM (n=1511) and nonDM (n=1884) cohorts included patients aged mean 64.16 (SD, 8.80) and 62.62 (SD, 10.29) years (P <.001), 73.7% and 79.8% were men (P <.001), 72.1% and 57.4% had hypertension (P <.001), and preoperative ejection fraction was 56.46% (SD, 12.32%) and 58.96% (SD, 10.78%; P <.001), respectively.

A similar proportion of the DM and nonDM patients received urgent CABG (1.75%-2.4%). During CABG, the patients with DM had more anastomoses (mean, 4.10 vs 3.87; P <.001), received more free grafts (1.5% vs 0.5%; P =.006), and fewer left internal thoracic artery in situ grafts (97.4% vs 98.9%; P =.001) compared with nondiabetic patients, respectively.

Postoperative mortality occurred at a rate of 0.32%, graft-related reoperation at 0.38%, and bleeding requiring reoperation at 1.08%. At 10 years, no difference in the rates of cardiac death (P =.186), MI (P =.846), repeat revascularization (P =.692), or MACE (P =.387) were observed on the basis of DM status, however, DM was associated with lower rates of graft failure (P =.009) and higher rates of stroke (P =.031) compared with no DM.

In the multivariate model, DM was associated with decreased risk for 10-year right internal thoracic artery graft failure (adjusted hazard ratio [aHR], 0.696; P =.025), FitzGibbon grade O graft failure (aHR, 0.752; P =.046), and internal thoracic artery graft failure (aHR, 0.767; P =.045) compared with no DM.

Due to the group differences at baseline, a propensity-matched subset of 1393 pairs of patients were compared. In this analysis, DM was associated with increased risk for wound infection (HR, 3.202; P <.001) and acute kidney injury (HR, 1.877; P =.001) at 30 days compared with no DM. In addition, the decreased risk for graft failures at 10 years observed in the adjusted analysis remained significant.

In a subgroup analysis, 752 patients had poorly-controlled and 516 had well-controlled DM. Compared with well-controlled DM, poorly-controlled DM was associated with decreased risk for 10-year revascularization in the multivariate analysis (aHR, 0.464; P =.036) and increased risk for 30-day wound infection in the propensity-matched analysis using 452 pairs (HR, 2.430; P =.004).

These findings may have been biased, as invasive imaging was not performed following CABG.

“In conclusion, OP [off-pump] CABG with BITA grafts showed excellent and comparable long-term clinical outcomes in patients with and without DM. DM might have a protective effect on competition and graft failure of ITA, and strict preoperative control of hyperglycemia with target HbA1c of <7% might reduce postoperative wound infection and facilitate the use of BITA in CABG.”