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Updated: Dec 7, 2025
Human Internal Mammary Artery IMA Transplantation and Stenting: A Human Model to Study the Development of In-Stent Restenosis
Published on: May 9, 2012
Short-Term Risk of Bilateral Internal Mammary Artery Grafting in Diabetic Patients
Toshinobu Kazui1, Scott D Lick1, Chiu-Hsieh Hsu2
1Division of Cardiothoracic Surgery, The University of Arizona, College of Medicine/Banner University Medical Center Tucson, Tucson, Arizona.
Insights
Bilateral internal mammary arteries (BIMA) use in coronary artery bypass grafting (CABG) shows increased sternal wound infection risk, especially with higher HbA1c levels. However, BIMA is a reasonable choice for patients with diabetes and HbA1c below 7%.
Area of Science:
- Cardiovascular Surgery
- Diabetology
- Surgical Infections
Background:
- Coronary artery bypass grafting (CABG) is a common procedure for coronary artery disease.
- The use of bilateral internal mammary arteries (BIMA) versus a single internal mammary artery (SIMA) is debated, particularly in diabetic patients.
- Preoperative HbA1c levels are a significant factor in surgical outcomes.
Purpose of the Study:
- To compare 30-day morbidity and mortality following CABG using BIMA versus SIMA.
- To evaluate the impact of preoperative HbA1c levels on outcomes in patients undergoing CABG with BIMA or SIMA.
Main Methods:
- Retrospective review of the Society of Thoracic Surgeons database (2008-2016).
- Propensity score matching of patients who received BIMA or SIMA.
- Subgroup analysis based on diabetes mellitus status and preoperative HbA1c levels (<7%, 7-9%, 9-11%, >11%).
Main Results:
- No significant difference in postoperative mortality between BIMA and SIMA groups (1.3% vs 1.2%).
- Sternal wound infection (SWI) rates were significantly higher with BIMA compared to SIMA across all HbA1c groups.
- SWI incidence increased with higher HbA1c levels in both BIMA and SIMA groups, with BIMA showing a greater relative increase.
Conclusions:
- While BIMA use is associated with increased SWI risk, it remains a reasonable option for CABG patients with a preoperative HbA1c below 7%.
- Careful patient selection and risk stratification are crucial when considering BIMA in diabetic patients undergoing CABG.
Abstract:
This study compares the morbidity and mortality at 30 days following the use of bilateral internal mammary arteries (BIMA) vs a single internal mammary artery (SIMA) at the time of coronary artery bypass grafting (CABG) in patients with a preoperative HbA1c. Patients undergoing CABG from January 2008 to December 2016 reported to the Society of Thoracic Surgeons database were retrospectively reviewed. The patients were divided into 2 groups: use of BIMA or use of SIMA and propensity matched. To assess the effect of preoperative HbA1c, both groups were further divided into 5 subgroups: patients without diabetes mellitus (DM), or patients with DM and a preoperative HbA1c level in one of four groups (< 7%, 7-9%, 9-11%, or >11%). The postoperative outcomes in both the BIMA and SIMA groups were compared. There were 700,504 and 28,115 patients with measured preoperative HbA1c levels in the SIMA and BIMA groups, respectively. Propensity score matching identified 23,635 comparable patients in each group for analysis. There was no difference in postoperative mortality between the BIMA and SIMA groups (1.3% vs 1.2%). The incidences of sternal wound infection (SWI) in patients undergoing placement of BIMA vs SIMA were: 0.8% vs 0.4% with no DM (P < 0.0001), 1.9% vs 1.0% with HbA1c < 7% (P < 0.001), 2.4% vs 1.2% with HbA1c 7-9% (P < 0.001), 2.8% vs 1.4% with HbA1c 9-11% (P = 0.02), 4.1% vs 1.5% with HbA1c > 11% (P = 0.01). Based on the incidence of SWI, BIMA is a reasonable approach with an HbA1c<7%.
