This article is more than 5 years old. Information may no longer be current.
ART: Outcomes of single, bilateral internal-thoracic-artery-grafting similar at 5 years
Click Here to Manage Email Alerts
NEW ORLEANS — Patients with symptomatic multivessel CAD undergoing CABG who received single or bilateral internal-thoracic-artery grafting had similar rates of death and composite CV events at 5 years, researchers reported at the American Heart Association Scientific Sessions.
However, evidence emerged suggesting early excess sternal wound complications may be associated with the bilateral approach.
David P. Taggart, MD, PhD, professor of cardiovascular surgery, University of Oxford, England, who presented 5-year data from the ART study, noted that this is “an interim analysis, which has limited power to detect differences in clinical outcomes. Longer-term follow-up will determine if there are benefits from the [bilateral approach].”
According to Taggart, the specified primary outcome of the ART trial is 10-year survival, and the results will be available in 2018.
The 5-year data presented here focused on a comparison of outcomes of 3,102 patients scheduled for CABG, including urgent cases and planned off-pump surgery, who were randomly assigned to undergo single (n = 1,554) or bilateral (n = 1,548) internal-thoracic-artery grafting. The study was conducted at 28 cardiac surgery centers in seven countries and patients were enrolled from June 2004 to December 2007.
The primary outcome was death from any cause at 10 years and the secondary outcome was a composite of death from any cause, MI or stroke at 5 and 10 years. The interim analyses were prespecified at 5 years of follow-up, according to the researchers.
At 5 years, 8.7% of the bilateral-graft group and 8.4% of the single-graft group had died (HR = 1.04; 95% CI, 0.81-1.32; P = .77). The rate of the composite outcome of death from any cause, MI or stroke was 12.2% in the bilateral-graft group vs. 12.7% in the single-graft group (HR = 0.96; 95% CI, 0.79-1.17; P = .69).
The bilateral-graft group had higher rates of sternal wound complications (3.5% vs. 1.9%; P = .005) and sternal reconstruction (1.9% vs. 0.6%; P = .002) compared with the single-graft approach.
In other results, both approaches yielded similar rates of major bleeding (2.6% single vs. 3.1% bilateral; HR = 1.18; 95% CI, 0.78-1.77) and need for repeat revascularization (6.6% single vs. 6.5% bilateral; HR = 0.98; 95% CI, 0.76-1.28).
“The left internal mammary artery is the standard of care for grafting the left anterior descending coronary artery during CABG,” Taggart said during a press conference. The use of the bilateral approach is low in current practice, used in “fewer than 10% [of cases] in Europe and fewer than 5% [of cases] in the United States.” However, previous observational data estimated a reduction in mortality of up to 20% with bilateral vs. single grafts, according to Taggart.
He also noted that possible explanations for the similarity in outcomes were that vein graft failure is known to be relatively low for the first 5 years after CABG and then accelerates; that there was very high use of guideline-based medical therapy in both groups that may have slowed vein graft failure; and that about 20% of the single group also received a radial artery that is known to lead to better clinical outcomes than vein grafts.
Approximately 14% of patients assigned to receive bilateral grafting received a single graft, and 2.4% of those assigned to receive a single graft actually received bilateral grafting, Taggart reported here. Patients in each group received a mean of three grafts. Forty percent of patients received off-pump procedures without the use of cardiopulmonary bypass. Loss to follow-up at 5 years was 4% to 5% in both groups, he said.
“This is a very large, well-designed study, with surprisingly no difference detected in all-cause mortality or in death, MI or stroke at 5 years. I was very surprised with the results … and also surprised there was no difference in the need for repeat revascularization at 5 years,” Frank Sellke, MD, chief of cardiothoracic surgery at Brown University and chairman of the Committee on Scientific Sessions Program for the AHA, said during a discussion of the results.
References:
Taggart DP, et al. LBCT.02 – Pioneering the Future of HeART Interventions. Presented at: American Heart Association Scientific Sessions; Nov. 12-16, 2016; New Orleans.
Taggart DP, et al. N Engl J Med. 2016;doi:10.1056/NEJMoa1610021.
Disclosure: Sellke and Taggart report no relevant financial disclosures.
Perspective
Back to Top
Timothy Gardner, MD
I was somewhat surprised that there weren’t better outcomes seen in the bilateral mammary artery graft patients because we know that we’re comparing a second mammary to vein grafts. We also know from the PREVENT trial and years of follow-up reports that vein graft failure is predictable and real. The other important point made by Dr. Taggart is that the benefit of the second mammary may be seen in patients who are in their second decade after CABG. I have no doubt, based on what we know about late mammary and vein graft patency, that for younger patients all arterial grafting is beneficial. The other interesting point is the impact of diabetes, obesity and chronic lung disease on the incidence of sternal wound problems. This is an important word of caution from this report that we really have to take seriously. However, I would have expected to see some benefit with bilateral mammary grafts at 5 years. Despite this 5-year follow-up information, I’m undeterred from my belief that for patients who are having CABG surgery in their 40s, 50s or early 60s, betting on arterial grafts that are going to outperform vein grafts in terms of long-term patency is the better strategy.
Click Here to Manage Email Alerts