Interpreting clinical outcomes using different strut thickness in coronary artery disease: insights from vascular imaging analysis

Abstract

Background: Coronary artery disease is a global health concern that necessitates treatments, such as percutaneous coronary intervention (PCI) with drug-eluting stents (DES). Recent advancements in biodegradable polymer-coated DES have improved long-term outcomes by reducing neointimal hyperplasia. Superior long-term outcomes in patients with ultrathin-strut sirolimus-eluting Orsiro stent (BP-SES) compared with those with thick-strut biolimus-eluting BioMatrix stent (BP-BES) have been shown. This study aimed to explore the mechanisms underlying these differences by using quantitative coronary angiography (QCA) and optical coherence tomography (OCT).

Methods: This sub-analysis of the BIODEGRADE trial, a prospective, randomized, multi-center study, compared BP-SES and BP-BES in patients who underwent PCI between July 2014 and September 2017. Patients with positive stress test results, ischemic symptoms, or those who consented to routine follow-up angiography were included. QCA and OCT were used to evaluate the lumen diameter, cross-sectional areas and stent apposition or coverage. OCT images were analyzed at 1 mm intervals within 5 mm proximal and distal to the stented segment.

Results: Of the 2,341 patients, 689 underwent follow-up angiography between 18- and 36-months post-PCI, and 929 stents were analyzed via QCA. OCT images of 61 participants were available. The BP-SES group exhibited a significantly larger minimal lumen diameter and reduced late lumen loss compared to the BP-BES group (0.34 ± 0.45 mm vs. 0.42 ± 0.44 mm, P = 0.005). OCT analysis showed significantly less neointimal hyperplasia in the BP-SES group (0.04 ± 0.4 mm2 vs. 0.64 ± 0.54 mm2, P < 0.001), with no significant differences in stent strut coverage or inflammation markers, than in the BP-BES group.

Conclusions: QCA and OCT analyses revealed less neointimal growth with BP-SES than with BP-BES, without delayed healing or increased inflammation. These findings underscore the importance of stent design characteristics and suggest that thinner struts may enhance clinical success by reducing restenosis and improving long-term vessel patency.