Does bilateral versus single thoracic artery grafting provide survival benefit in female patients?

Abstract

Bilateral internal thoracic artery (BITA) grafting is associated with improved survival, but this technique is reluctantly used in women due to an increased risk of sternal wound infection. The aim of this study was to compare the long-term survival of women who underwent BITA grafting and single internal thoracic artery (SITA) grafting. We performed a retrospective analysis of 556 consecutive female BITA patients and 685 female SITA patients. SITA patients were older and more likely to have comorbidities (diabetes mellitus, chronic lung disease, chronic renal failure, peripheral vascular disease and cerebral vascular disease). Operative mortality showed a trend towards a benefit for BITA (2.9% vs 5.0% for SITA, P = 0.06). The sternal wound infection rates were similar (3.4% vs 2.9%, P = 0.6); however, the occurrence of stroke was significantly lower in the SITA group (3.4% vs 1.2%, P = 0.007). The median survival of the BITA group was significantly better {13.8 years [95% confidence interval (CI) 12.8-14.9] vs 10.3 years [95% CI 9.6-11.1], P = 0.001}. After propensity score matching (491 pairs), the assignment to BITA was not associated with increased early mortality or complication rates, and the choice of BITA grafting was associated with better survival [14.5 years (95% CI 13.3-15.6) vs 11.8 years (95% CI 10.7-12.9)]. Only the choice of conduits was associated with increased late mortality (multivariable analysis, hazard ratio 1.28, 95% CI 1.024-1.591; P = 0.03). The low early mortality and complication rate, and the long-term survival benefit of BITA compared to SITA grafting, support the use of BITA grafting in women.