Bilateral Internal Mammary Artery Use in Diabetic Patients: Friend or Foe?

Meta-analysis of BITA versus SITA grafting in diabetic patients: evidence from propensity score-matched studies

BACKGROUND

It has been demonstrated that the use of bilateral internal thoracic artery (BITA) grafting in coronary artery bypass grafting (CABG) improves long-term survival in comparison to the use of a single internal thoracic artery (SITA) graft. However, the optimal transplantation technique for diabetic patients remains undetermined. The purpose of this meta-analysis was to compare the effectiveness and safety of BITA and SITA CABG in diabetic patients.

METHODS

A comprehensive search of Google Scholar, Science Direct, and PubMed was conducted for studies with propensity score-matched comparing between BITA and SITA grafting in diabetic patients. The main goal was to know mid- to long-term mortality, and the supplementary results included incidence of deep sternal wound infection, 30-day mortality, and incidence of reoperation due to hemorrhage.

RESULTS

The meta-analysis included 11 studies involving 3762 diabetic patients with matched propensity scores. Compared to SITA grafting, BITA grafting was associated with a significant reduction in long-term mortality (HR 0.78; 95% CI 0.67-0.91), P = 0.03, I2 = 54%. There were no significant differences between the two groups in terms of 30-day mortality, reoperation for bleeding, cerebrovascular accident, or renal failure.

CONCLUSIONS

BITA grafting appears to provide better overall survival than SITA grafting in patients with diabetes. However, using BITA grafting is associated with a greater risk of deep sternal wound infection. These findings may help guide the choice of grafting technique in diabetic patients undergoing CABG.

Bilateral versus single internal mammary artery in diabetic patients: systematic review and meta-analysis

OBJECTIVES

Data on bilateral internal mammary artery (BIMA) versus single internal mammary artery (SIMA) on diabetics were analyzed; This is the only meta-analysis, the last 7 years.

METHODS

Medline through PubMed/EMBASE/CINHAL and the Cochrane Central Register of Controlled Trials; 179 articles were studied; 19 studies deemed suitable and were included in the analysis.

RESULTS

The mortality was 2.41% for BIMA versus 1.71% for SIMA (odds ratio [OR] =  0.95; 95% confidence interval [CI]: 0.74-1.22). Postoperative reopening for bleeding was higher at 3.75% for BIMA versus 2.91% for SIMA (OR =  1.49; 95% CI: 1.15-1.93). The incidence of MI was 0.87% for BIMA versus 0.83% for SIMA (OR =  0.73; 95% CI: 0.37-1.44). Deep sternal wound infection was 3.02% for BIMA and 1.95% for SIMA (OR =  1.57; 95% CI: 1.26-1.95). When skeletonized, the incidence of DSWI was 2.5% for BIMA versus 2.41% for SIMA. There was a significant difference at 5-year survival favoring the BIMA, 85.15% BIMA versus 80.77% SIMA (OR =  1.79; 95% CI: 1.60-2.01). The 10-year overall survival was 74.04% BIMA versus 61.57% SIMA (OR =  1.79; 95% CI: 1.61-1.98). The 15-year survival was 47.08% for BIMA versus 37.06% for SIMA (OR =  1.69; 95% CI: 1.52-1.88).

CONCLUSIONS

Postoperative bleeding was higher in BIMA group. Bilateral internal mammary artery in diabetic patients should be carried out in a skeletonize fashion, to reduce DSWI. There is a survival benefit of using BIMA in diabetics within 5 years of surgery; it remains significant up to 15 years.

Bilateral internal thoracic artery versus single internal thoracic artery: a meta-analysis of propensity score-matched observational studies

The lack of benefit in terms of mid-term survival and the increase in the risk of sternal wound complications published in a recent randomized controlled trial have raised concerns about the use of bilateral internal thoracic artery (BITA) in myocardial revascularization surgery. For this reason, we decided to explore the current evidence available on the subject by carrying out a meta-analysis of propensity score-matched studies comparing BITA versus single internal thoracic artery (SITA). PubMed, EMBASE and Google Scholar were searched for propensity score-matched studies comparing BITA versus SITA. The generic inverse variance method was used to compute the combined hazard ratio (HR) of long-term mortality. The DerSimonian and Laird method was used to compute the combined risk ratio of 30-day mortality, deep sternal wound infection and reoperation for bleeding. Forty-five BITA versus SITA matched populations were included. Meta-analysis showed a significant benefit in terms of long-term survival in favour of the BITA group [HR 0.78; 95% confidence interval (CI) 0.71-0.86]. These results were consistent with those obtained by a pooled analysis of the matched populations comprising patients with diabetes (HR 0.65; 95% CI 0.43-0.99). When compared with the use of SITA plus radial artery, BITA did not show any significant benefit in terms of long-term survival (HR 0.86; 95% CI 0.69-1.07). No differences between BITA and SITA groups were detected in terms of 30-day mortality or in terms of reoperation for bleeding. Compared with the SITA group, patients in the BITA group had a significantly higher risk of deep sternal wound infection (risk ratio 1.66; 95% CI 1.41-1.95) even when the pooled analysis was limited to matched populations in which BITA was harvested according to the skeletonization technique (risk ratio 1.37; 95% CI 1.04-1.79). The use of BITA provided a long-term survival benefit compared with the use of SITA at the expense of a higher risk of sternal deep wound infection. The long-term survival advantage of BITA is undetectable when compared with SITA plus radial artery.