Are all forms of total arterial revascularization equal? A comparison of single versus bilateral internal thoracic artery grafting strategies

Abstract

Objective: Total arterial revascularization (TAR) with internal thoracic arteries (ITAs) and radial arteries (RA) is associated with greater long-term survival compared with the use of a single internal thoracic artery supplemented by veins. The optimal conduit choice and configuration in achieving TAR remains controversial, with uncertainty regarding the individual prognostic impact of ITAs and RAs. As such, among patients solely undergoing TAR, we compared long-term survival between patients receiving single thoracic arteries and those receiving bilateral ITAs.

Methods: From 1995 to 2010, 2821 patients with 3-vessel coronary artery disease at 8 centers underwent primary isolated coronary artery bypass with TAR using ITAs and RAs. Bilateral ITAs were used in 912 patients. In 380 cases, bilateral in situ ITAs were grafted to the left coronary system. RAs were used in 848 patients (93%) receiving bilateral ITAs and 1906 patients (99.8%) receiving single ITAs. Survival data were obtained using the National Death Index. Separate 1:1 propensity score-matched analyses were performed for (1) bilateral ITA versus single ITA and (2) bilateral ITA incorporating a free right ITA versus single ITA and RAs. Among the 912 patients with bilateral ITAs, those receiving an in situ right ITA to the left coronary system were compared with those receiving a free right ITA.

Results: In the propensity score-matched analysis comparing bilateral versus single ITAs (591 matched pairs), there were similar rates of 30-day mortality and deep sternal wound infection. Bilateral ITA use was associated with greater 15-year survival (79% ± 3.9% vs 67% ± 4.7%, P < .001). In the analysis between bilateral ITA incorporating a free right ITA versus single ITA + RAs (380 matched pairs), bilateral ITA use demonstrated comparable survival at 15 years (79% ± 4.7% vs 67% ± 5.7%, P = .09). Among patients receiving bilateral ITAs, comparison between in situ right ITA versus free right ITA recipients (206 matched pairs) revealed comparable 15-year survival (84% ± 6.1% vs 79% ± 6.7%, P = .13). Multivariable Cox regression found bilateral ITA use to be protective from mortality (hazard ratio, 0.73; 95% confidence interval, 0.59-0.90, P = .004).

Conclusions: The use of bilateral ITAs as an in situ or free conduit is associated with greater survival and seems to offer a prognostic advantage over the use of only a single ITA supplemented by RAs. Therefore, all configurations of TAR are not equivalent.

Keywords: arterial grafting; coronary artery bypass grafting; coronary artery disease; coronary revascularization; internal thoracic artery; radial artery; surgery.