No significant difference in rate of death was found in patients who underwent either bilateral or single internal thoracic artery grafting during coronary artery bypass grafting (CABG) surgery, according to a randomized trial of patients who were scheduled to undergo CABG.

David P. Taggart, MD, PhD

“At 10 years, in intention-to-treat analyses, there were no significant between-group differences in all-cause mortality,” wrote lead author David P. Taggart, MD, PhD, of the University of Oxford (England), and his coauthors, adding that “the results of this trial are not consistent with data from previous, nonrandomized studies.” The study was published in the New England Journal of Medicine.

In the multicenter, unblinded Arterial Revascularization Trial (ART), 3,102 patients with multivessel coronary artery disease were divided into two groups: the bilateral-graft group (1,548 patients) and the single-graft group (1,554). They were assigned to receive bilateral internal thoracic artery grafts or a standard single left internal thoracic artery graft during CABG, respectively. However, 13.9% of the patients in the bilateral-graft group received only a single internal thoracic artery graft, while 21.8% of those in the single-graft group also received a radial artery graft.

At 10-year follow-up, 644 patients (20.8%) had died; 315 deaths (20.3%) occurred in the bilateral-graft group and 329 (21.2%) occurred in the single-graft group. A total of 385 patients (24.9%) suffered MI, stroke, or death in the bilateral-graft group, compared with 425 (27.3%) in the single-graft group (hazard ratio, 0.90; 95% confidence interval, 0.79-1.03).

The coauthors noted several reasons that the results of their trial may not have matched previous data, including conflicting evidence about vein graft failure’s clinical effect on survival and the aforementioned patients who were assigned to a specific group but received alternate grafting. In addition, they acknowledged that ART was an unblinded trial and “biases may be introduced in the treatment of patients, depending on their randomization assignment.”

The study was supported by grants from the British Heart Foundation, the U.K. Medical Research Council, and the National Institute of Health Research Efficacy and Mechanistic Evaluation Program. No relevant conflicts of interest were reported.

SOURCE: Taggart DP et al. N Engl J Med. 2019 Jan 31. doi: 10.1056/NEJMoa1808783.