Multi arterial grafting survival exceeds conventional CABG, PCI

A large, 16-year single-center study of patients with multi vessel disease has determined that multi vessel coronary artery bypass grafting achieved longer survival than not only percutaneous coronary interventions, but also conventional coronary artery bypass grafting, researchers from the Mayo Clinic reported in the August issue of the Journal of Thoracic and Cardiovascular Surgery.

Lead author Chaim Locker, MD, and his colleagues said the use of what they called Multi Art, for multi vessel arterial grafting, also known as MAG, “must increase.”

The evolution of bare-metal and then drug-eluting stents may have favored percutaneous coronary interventions (PCI) over coronary artery bypass grafting (CABG), but, Dr. Locker and his coauthors said, “Evidence is accumulating that late outcome of surgical revascularization is improved when at least two arterial grafts are used.”

The study analyzed results of 12,615 patients who had either isolated primary CABG (6,667) or PCI (5,948) from 1993 to 2009. Among the CABG patients, 5,712 had the more conventional approach involving arterial grafts into the left internal thoracic artery/saphenous vein (ITA/SV) and 955 had MAG. Patients in the PCI group had three different procedures: balloon angioplasty (1,020), drug-eluting stent (1,686), or bare-metal stent (3,242). The study excluded patients who had revascularization procedures after a heart attack.

While the overall 15-year survival for patients with CABG was lower than it was for those who had PCI (36% vs. 46%), the survival for those who had MAG was significantly higher: 65% vs. 31% for those who had left ITA/SV revascularization. 8-year survival for the MAG subgroup was also significantly higher than all other subgroups: 87% vs. 69% for left ITA/SV, 75% for bare-metal stent, 73% for balloon angioplasty, and 70% for drug-eluting stent.

Propensity matching found similar survivability for balloon angioplasty and left ITA/SV when compared with MAG: 66% for MAG vs. 57% for the former; and 64% for MAG vs. 56% for the latter. The researchers also estimated the hazard ratio during the first 5 years of follow-up and found that those who had bare-metal stents had “significantly worse” survival, compared with MAG, but that survival evened out after that. Survival in the bare-metal stent group was similar to that of the left ITA/SV group, but “significantly worse” during the first 5 years for those who had balloon angioplasty.

Dr. Locker and his colleagues acknowledged that multiple randomized studies have compared CABG and PCI over the years, but they said that in most of those studies “the enrolled patients were highly selected and likely did not represent the broader population of patients with MVD [multi vessel disease] undergoing revascularization.” With the exception of the SYNTAX trial (Synergy Between PCI With Taxus and Cardiac Surgery), those studies did not report on the frequency of MAG within the study population. The Mayo study, on the other hand, included all treated patients, excluding those who had a previous heart attack.

However, MAG is used infrequently, Dr. Locker and his colleagues said. The average annual rate of MAG in their Mayo practice was 15.2%, higher than the 5% annual rate the Society of Thoracic Surgeons National Cardiac Surgery Database reported, and higher than the 12% rate in Europe. The SYNTAX trial reported an annual MAG rate of 27.6% for all CABG cases.

“It seems clear that use of Multi Art should be more frequent in patients with MVD undergoing CABG,” Dr. Locker and his coauthors said. “Multi Art can be used in most patients with MVD, including diabetic patients and elderly patients, and this strategy will improve outcomes of surgical revascularization.”

Dr. Locker and his coauthors had no financial relationships to disclose.