There are few long-term data on neointimal healing and neoatherosclerosis development following primary percutaneous coronary intervention (PCI) with implantation of an everolimus-eluting bioresorbable vascular scaffold (BVS) (ABSORB BVS 1.0, Abbott Vascular). In addition, the causes behind late scaffold failure have yet to be fully understood.
This study looked at the healing pattern and existence of neoatherosclerosis in patients suffering from 12 ST-segment elevation myocardial infarction (STEMI) who underwent serial optical coherence tomography (OCT) evaluations at baseline, 12, 24, and 60 months following PCI.
The study was conducted at a single center and followed a prospective and longitudinal study design. In 12 patients with STEMI, serial optical coherence tomography (OCT) assessments were done at baseline, 12, 24, and 60 months following PCI. The average period of follow-up was 59 months.
As measured by angiography, the diameter stenosis rose from 7.11 ± 4.99 % at 1 year to 21.00 ± 11.31 % at 5 years (p = 0.03). However, during the follow-up period, the minimal lumen diameter remained steady. During the 5 year follow-up, the minimum lumen area decreased by 1.00 ± 1.57 mm2, while the mean lumen area declined by 1.75 ± 0.87 mm2. Between 2 and 5 years of follow-up there was stable luminal dimensions. Over the course of 60 months, no change was observed in the lumen eccentricity (0.85± 0.03) and asymmetry (0.43± 0.10) indexes. In both the in-scaffold (IS) and out-scaffold (OS) regions, the incidence of atherosclerosis was high, with calcifications (IS = 100%, OS = 92%, p = 0.99), macrophages (IS = 92% and OS = 67%, p = 0.31), and neovascularization (IS = 75%, OS = 50%, p = 0.40).
Serial OCT imaging of STEMI patients up to 5 years after BVS implantation showed complete scaffold resorption, high prevalence of neoatherosclerosis, and stable lumen area after a period of neointima expansion in the first two years following PCI.