BIMA Grafting in Non-Diabetic Elderly CABG Patients
In non-diabetic elderly patients undergoing CABG without additional high-risk factors for sternal complications, BIMA grafting should be considered appropriate, though the survival benefit in this specific population remains uncertain and must be weighed against the 3-fold increased risk of sternal reconstruction.
Evidence from the Arterial Revascularization Trial
The ART trial, the only randomized controlled trial directly comparing BIMA versus single IMA (SIMA), demonstrated that BIMA grafting was as safe as SIMA grafting in the short term 1. Key findings include:
- 30-day mortality was identical at 1.2% in both groups 1
- 1-year mortality was comparable at 2.3% for SIMA versus 2.5% for BIMA 1
- No differences in stroke, MI, or repeat revascularization were observed 1
- Sternal reconstruction risk was significantly increased with BIMA: relative risk 3.24 (95% CI: 1.54–6.83) 1
Long-Term Survival Considerations
While observational data suggests mortality benefit, the evidence is nuanced:
- Meta-analysis of observational studies showed BIMA associated with reduced death risk: HR = 0.81 (95% CI: 0.70–0.94) 1
- The added benefit in older patients is less well documented compared to younger patients 1
- Extended 10-year follow-up from ART is still pending and will hopefully determine whether survival with BIMA is truly superior 1
Age-Specific Recommendations
The evidence suggests a stratified approach based on age:
- For younger patients (≤60 years), complete arterial revascularization including BIMA is particularly reasonable with few comorbidities 2
- For elderly patients, the survival advantage becomes less certain, as the added benefit of a second arterial graft in older patients is less well documented 1
- Patients with multivessel disease at younger age derive clear survival benefit from total arterial grafting with BIMA 1
Technical and Safety Considerations in Non-Diabetics
Non-diabetic status removes a major concern regarding BIMA use:
- Diabetes is NOT a contraindication to BIMA - multiple studies show comparable sternal wound complication rates between diabetic and non-diabetic patients receiving BIMA 3, 4, 5
- In non-diabetics without additional risk factors, the baseline risk of sternal complications is already lower, making BIMA more favorable 3
- The procedure adds only 23 minutes to an operation that takes 3-4 hours 1
Practical Algorithm for Decision-Making
Consider BIMA appropriate when ALL of the following are met:
- Patient age <70 years (stronger evidence for benefit) 2
- No additional high-risk factors for sternal complications (obesity, COPD, chronic renal failure) 6
- Experienced surgeon performing the procedure 2
- Multivessel coronary disease requiring multiple grafts 1
- Good life expectancy (>10 years) to realize potential long-term benefits 6
Exercise caution or consider SIMA when:
- Age ≥75 years where long-term benefit is uncertain and operative time considerations become more important 1
- Limited life expectancy from comorbidities where short-term risks outweigh uncertain long-term benefits 6
- Surgeon inexperience with BIMA technique, as 16.4% of patients randomized to BIMA in ART did not receive allocated treatment 1
Critical Caveats
The major limitation is that definitive survival benefit data in elderly patients specifically is lacking - the ART trial's 10-year follow-up results are still pending 1. The early vein graft failure rate of 10-26% between 12-18 months supports arterial grafting even in older patients 1, 7, but this must be balanced against the 3-fold increased sternal reconstruction risk 1.
Underutilization remains a problem - only 4% of CABG procedures in the USA use BIMA despite potential benefits 1. This low adoption rate stems from technical demands, time requirements, and fear of complications rather than evidence-based contraindications 1.