Coronary stent implantation guided by intravascular ultrasound reduces the 1-year rate of major adverse cardiac events in patients who have long lesions, compared with standard angiography-guided stent implantation, Dr. Sung-Jin Hong reported at the American Heart Association annual scientific sessions, a presentation that was simultaneously published online Nov. 10 in JAMA.
Even though four meta-analyses have demonstrated the superiority of IVUS-guided implantation and recent guidelines recommend IVUS guidance for select patients to optimize results, “the effect of IVUS-guided drug-eluting stent implantation on clinical outcomes remains uncertain because of the limited number of properly powered randomized clinical trials,” said Dr. Hong of Sanggye Paik Hospital at Inje University and of Severance Cardiovascular Hospital at Yonsei University, both in Seoul, South Korea.
Dr. Hong and his associates performed a 4-year industry-sponsored randomized trial comparing the two techniques in 1,400 patients who had typical chest pain or evidence of myocardial ischemia and were eligible to receive an everolimus-eluting stent of 28 mm or more in length. The study participants were randomly assigned to undergo either IVUS-guided (700 patients) or angiography-guided (700 patients) stent implantation at 20 Korean medical centers and were followed up for 1 year. The mean patient age was 64 years, and 69% of the participants were men. The mean stent length of the targeted lesions was 39.3 mm.
The primary endpoint – a composite of major adverse cardiac events such as death, target-lesion-related MI, or ischemia-driven revascularization of the target lesion at 1 year – occurred in 2.9% of the IVUS group and 5.8% of the angiography group. This is a significant difference, with the IVUS group showing a 2.9% absolute reduction and a 48% relative reduction in the primary endpoint, the investigators said (JAMA 2015 Nov 10. doi: 10.1001/jama.2015.15454).
The superiority of IVUS-guided stent implantation was attributable primarily to a marked decrease in target-lesion revascularization in that group (2.5% of patients) compared with the angiography-guided group (5.0%). This in turn was likely due to the fact that adjunctive poststent balloon dilation was done more frequently in the IVUS group (76% vs 57%) and that the mean final balloon size was larger. Consequently, the minimum lumen diameter was greater in the IVUS-guided stent group than in the angiography-guided stent group.
“To our knowledge, [this] is the first demonstration of the clinical benefit of IVUS guidance in second-generation drug-eluting stent implantation in an adequately powered randomized clinical trial,” the investigators added.