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Updated: Mar 3, 2026
Human Internal Mammary Artery IMA Transplantation and Stenting: A Human Model to Study the Development of In-Stent Restenosis
Published on: May 9, 2012
One-year costs of bilateral or single internal mammary grafts in the Arterial Revascularisation Trial
Alastair M Gray1, Jacqueline Murphy1, Douglas G Altman2
1Nuffield Department of Population Health, Health Economics Research Centre, University of Oxford, Headington, UK.
Insights
Bilateral internal mammary artery (BIMA) coronary artery bypass grafting (CABG) is more costly than single internal mammary artery (SIMA) CABG due to longer operating times and sternal wound issues. Further follow-up is needed to assess long-term graft patency and survival benefits.
Area of Science:
- Cardiovascular Surgery
- Health Economics
- Clinical Trials
Background:
- Coronary artery bypass grafting (CABG) is a standard treatment for coronary artery disease.
- Bilateral internal mammary artery (BIMA) grafting may offer survival benefits over single internal mammary artery (SIMA) grafting.
- Concerns exist regarding the increased surgical complexity, cost, and potential for impaired sternal wound healing with BIMA.
Purpose of the Study:
- To conduct a detailed 12-month comparison of healthcare resource utilization and costs between BIMA and SIMA CABG.
- To evaluate the economic impact of BIMA versus SIMA grafting within the Arterial Revascularisation (ART) Trial.
Main Methods:
- A randomized trial involving 3102 patients across 28 hospitals in seven countries.
- Patients were assigned to either BIMA (n=1548) or SIMA (n=1554) CABG surgery.
- Detailed resource use data were collected, and costs were calculated using UK unit costs over 12 months post-randomization.
Main Results:
- BIMA patients had longer operative times (20 minutes longer) and required more treatment for sternal wound problems.
- Mean total costs per patient at 12 months were £13,839 for BIMA versus £12,717 for SIMA, a difference of £1122 (p=0.002).
- Approximately 9% higher costs for BIMA were primarily attributed to longer in-theater and in-hospital stays, and sternal wound management.
Conclusions:
- At 12 months, BIMA CABG is associated with higher healthcare costs compared to SIMA CABG.
- The increased costs are mainly driven by operative time, hospital stay, and sternal wound complications.
- Longer-term follow-up is necessary to determine if potential survival advantages of BIMA outweigh the initial economic and wound healing considerations.
Objective:
Coronary artery bypass grafting (CABG) using bilateral internal mammary arteries (BIMA) may improve survival over CABG using single internal mammary arteries (SIMA), but may be surgically more complex (and therefore costly) and associated with impaired sternal wound healing. We report, for the first time, a detailed comparison of healthcare resource use and costs over 12 months, as part of the Arterial Revascularisation (ART) Trial.
Methods:
3102 patients in 28 hospitals in seven countries were randomised to CABG surgery using BIMA (n=1548) or SIMA (n=1554). Detailed resource use data were collected covering surgery, the initial hospital episode, and for 12 months post randomisation. Using UK unit costs, total costs were calculated and compared between trial arms and for subgroups.
Results:
Patients randomised to BIMA spent 20 min longer in theatre (95% CI 15 to 25, p<0.001) and also required more treatment for sternal wound problems. Mean (SD) total costs per patient at 12 months were £13 839 (£10 534) for BIMA and £12 717 (£9719) for SIMA (mean cost difference £1122, 95% CI £407 to £1838, p=0.002). No tests for interaction between subgroups and treatment allocation were significant.
Conclusions:
At 12 months from randomisation, mean costs were approximately 9% higher in BIMA than SIMA patients, primarily due to longer time in theatre and in-hospital stay, and slightly higher costs related to sternal wound problems during follow-up. Follow-up to the primary trial endpoint of 10 years will reveal whether longer-term differences emerge in graft patency or in overall survival.
Trial Registration Number:
Controlled-trials.com (ISRCTN46552265).
