Dynamics of Vessel Wall Changes Studied After Absorb Bioresorbable Scaffold Implantation

December 2, 2013—In EuroIntervention, Patrick W. Serruys, MD, et al published findings online ahead of print from a study conducted to assess observations with multimodality imaging of the Absorb bioresorbable everolimus-eluting vascular scaffold (Abbott Vascular, Santa Clara, CA) performed in two consecutive cohorts of patients who were serially investigated either at 6 and 24 months or at 12 and 36 months. The investigators looked at patients from the ABSORB clinical investigation, cohort B (ABSORB B).

As summarized in EuroIntervention, 45 patients (cohort B1) and 56 patients (cohort B2) from the ABSORB multicenter, single-arm trial underwent serial invasive imaging, specifically quantitative coronary angiography, intravascular ultrasound (IVUS), radiofrequency backscattering, and optical coherence tomography (OCT).

The investigators reported that between 1 and 3 years, late luminal loss remained unchanged (6 months: 0.19 mm; 1 year: 0.27 mm; 2 years: 0.27 mm; 3 years: 0.29 mm), and the in-segment angiographic restenosis rate for the entire cohort B (n = 101) at 3 years was 6%.

On IVUS, mean lumen, scaffold, plaque, and vessel area showed enlargement up to 2 years. Mean lumen and scaffold area remained stable between 2 and 3 years, whereas significant reduction in plaque behind the struts occurred with a trend toward adaptive restrictive remodelling of external elastic membrane. Hyperechogenicity of the vessel wall, a surrogate of the bioresorption process, decreased from 23.1% to 10.4%, with a reduction of radiofrequency backscattering for dense calcium and necrotic core.

At 3 years, the count of strut cores detected on OCT increased significantly, which the investigators stated probably reflects the dismantling of the scaffold; 98% of struts were covered. In the entire cohort B (n = 101), the 3-year major adverse cardiac event rate was 10% without any scaffold thrombosis.

The current investigation demonstrated the dynamics of vessel wall changes after implantation of a bioresorbable scaffold, resulting at 3 years in stable luminal dimensions, a low restenosis rate, and a low clinical major adverse cardiac events rate, concluded the investigators in EuroIntervention.