A 5-year follow-up of the ABSORB trial revealed that in a simple stenotic lesion, bioresorbable scaffold implantation resulted in stable lumen dimensions, low restenosis, and low rates of major adverse cardiac events (MACE).
Angiographic luminal late loss was unchanged between 6 months and 1 year, and 5 years in 2 groups of patients who underwent coronary angiography, intravascular ultrasound (IVUS), and optical coherence tomography (OCT) at different times. Luminal late loss was 0.15 ± 0.20 mm vs 0.15 ± 0.24 mm (P=.8275) when patients with target lesion revascularization were included for the first group and 0.30 ± 0.37 mm vs 0.32 ± 0.48 mm (P=.8204) for the second group.
Later, at 5 years, in-scaffold and in-segment binary restenosis was 7.8% and 12.5%.Using IVUS, the minimum lumen area of the first group decreased from 5.23 ± 0.97 mm2 at 6 months to 4.89 ± 1.81 mm2 at 5 years (P=.04), but remained unchanged in the second group at 5 years. A vasomotion test detected vasodilation in 85% of the scaffold segments, ranging from 0.07% to 9.49%.
Total plaque media decreased in both patient groups on IVUS from 6 to 12 months to 60 months (P=.023 and P<.0001). “The most striking observations are the decrease in plaque media together with adaptive, constrictive remodel of the vessel area,” researchers noted. “In the absence of local detection of any inflammatory biomarkers (such as metalloproteinases or cytokines) that would account for positive or negative biological remodeling, it is difficult to allude to atherosclerotic progression and/or regression.”
Struts were no longer discernible via OCT or IVUS at the 5-year mark and the overall the 5-year MACE event rate was 11% without scaffold thrombosis.
“Five years ago, this first-in-man study aimed to demonstrate feasibility and safety as well as to understand, with multimodality imaging, the biological reaction of the vessel wall following the implantation of a bioresorable scaffold,” researchers wrote. “The current study confirms the long-term safety of the Absorb scaffold for treatment of relatively simple coronary artery stenosis, with demonstration of stable lumen dimensions from the mid- to long-term by invasive imaging.”
Given that the study was relatively small in size—only a total of 101 patients were included—larger-scale randomized trials are needed to confirm clinical advantages of bioresorbable scaffolds in patients with stenotic coronary atherosclerotic lesions.
Serruys PW, Ormiston J, van Geuns RJ, et al. A polyactide bioresorbable scaffold eluting everolimus for treatment of coronary stenosis. 5-year follow-up. J Am Coll Cardiol. 2016;67(7):766-776. doi: 10.1016/j.jacc.2015.11.060.