Outcomes following surgical revascularization with single versus bilateral internal thoracic arterial grafts in patients with left main coronary artery disease undergoing coronary artery bypass grafting: insights from the EXCEL trial†.

Abstract

Observational data suggest that the use of a single internal thoracic artery (SITA) may result in inferior outcomes compared with bilateral internal thoracic artery (BITA) use for coronary artery bypass grafting (CABG)-a finding not yet supported by randomized trial outcomes. However, the optimal number of internal thoracic artery grafts in patients with left main coronary artery disease has not been investigated. The EXCEL trial randomized 1905 patients with left main coronary artery disease to percutaneous coronary intervention with everolimus-eluting stents versus CABG. Among the 905 patients undergoing CABG, 688 (76.0%) received SITA and 217 (24.0%) received BITA. Differences in clinical event rates were estimated using the Kaplan-Meier method and compared with the log-rank test. Multivariable Cox regression was used to adjust for differences in baseline covariates. Compared to SITA, patients treated with BITA were younger (66.1 ± 9.5 vs 64.5 ± 9.3 years, P = 0.020), were less likely female (24.3% vs 14.3%, P = 0.002) and diabetic (28.8% vs 15.2%, P < 0.001), and had a lower prevalence of peripheral vessel disease (10.2% vs 5.5%, P = 0.040). The unadjusted 3-year composite primary endpoint of death, stroke or myocardial infarction (MI) occurred in 15.6% of SITA vs 11.6% of BITA patients (P = 0.17). The SITA group tended to have a higher 3-year rate of all-cause death compared with the BITA group (6.7% vs 3.3%; P = 0.070). Stroke, MI and ischaemia-driven revascularization outcomes were not significantly different between groups. After adjusting for baseline differences, neither the composite of death, stroke or MI [hazard ratio (HR) 1.12, 95% confidence interval (CI) 0.71-1.78; P = 0.62] nor mortality (HR 1.36, 95% CI 0.60-3.12; P = 0.46) was significantly higher with SITA. The rehospitalization rate after 3 years was higher in the SITA group (35.8% vs 26.0%, P = 0.008), a difference which was no longer present after multivariable adjustment (HR 1.27, 95% CI 0.93-1.74; P = 0.13). Sternal wound dehiscence within 30 days did not occur more often in the BITA group compared to the SITA group (1.8% vs 2.2%, P > 0.99). In the EXCEL trial, there were no clinical differences at 3 years between SITA or BITA revascularization in patients with left main coronary artery disease.