Routine use of bilateral internal thoracic artery grafting in women does not increase in-hospital mortality and could improve long-term survival.

Background: Bilateral internal thoracic artery (BITA) grafting is underused in women.

Methods: Outcomes of 798 consecutive women with multivessel coronary disease who underwent isolated coronary surgery (1999-2016) using BITA (n=530, 66.4%) or single internal thoracic artery (SITA) grafting (n=268, 33.6%) were reviewed retrospectively. Differences between BITA and SITA cohort were adjusted by propensity score matching. For both series, late survival was estimated with the Kaplan-Meier method.

Results: One-to-one propensity score matching resulted in 247 BITA/SITA pairs with similar baseline characteristics and risk profile. According to the propensity matching, BITA grafting was associated with a trend towards reduced in-hospital mortality (3.2% vs. 5.7%, p=0.19). However, BITA women had an increased chest tube output (p=0.0076) as well as higher rates of any (13% vs. 5.3%, p=0.003) and deep sternal wound infections (9.3% vs. 4.9%, p=0.054), this translating in a longer in-hospital stay (10 vs. 9days, p=0.029). Test for interaction showed that body mass index >30kg/m and extracardiac arteriopathy were associated with a higher risk of deep sternal wound infection in BITA than in SITA women (23.4% vs. 13.7%, p<0.001 and 23.9% vs. 3.4%, p=0.001, respectively). Freedom from all-cause death and cardiac or cerebrovascular death were improved in BITA cohort, even though the differences were not quite significant (p=0.16 and 0.076, respectively).

Conclusions: When routinely performed, BITA grafting does not increase in-hospital mortality in women and could improve long-term survival. However, its use should be avoided in obese women with extracardiac arteriopathy because of increased risk of deep sternal wound infection.