Mechanical properties of the everolimus-eluting bioresorbable vascular scaffold compared to the metallic everolimus-eluting stent

BMC Cardiovascular Disorders, May 2016

Background Everolimus-eluting bioresorbable vascular scaffolds (BVS) represent an innovative treatment option for coronary artery disease. Clinical and angiographic results seem promising, however, data on its immediate procedural performance are still scarce. The aim of our study was to assess the mechanical properties of BVS by Optical Coherence Tomography (OCT) in clinical routine. Methods Post-implantation OCT images of 40 BVS were retrospectively compared to those of 40 metallic everolimus-eluting stents (EES). Post-procedural device related morphological features were assessed. This included incidences of gross underexpansion and the stent eccentricity index (SEI, minimum/maximum diameter) as a measure for focal radial strength. Results Patients receiving BVS were younger than those with EES (54.0 ± 11.2 years versus 61.7 ± 11.4 years, p = 0.012), the remaining baseline, vessel and lesion characteristics were comparable between groups. Lesion pre-dilatation was more frequently performed and inflation time was longer in the BVS than in the EES group (n = 34 versus n = 23, p = 0.006 and 44.2 ± 12.8 versus 25.6 ± 8.4 seconds, p < 0.001, respectively). There were no significant differences in maximal inflation pressures and post-dilatation frequencies with non-compliant balloons between groups. Whereas gross device underexpansion was not significantly different, SEI was significantly lower in the BVS group (n = 12 (30 %) versus n = 14 (35 %), p = 0.812 and 0.69 ± 0.08 versus 0.76 ± 0.09, p < 0.001, respectively). There was no difference in major adverse cardiac event-rate at six months. Conclusion Our data show that focal radial expansion was significantly reduced in BVS compared to EES in a clinical routine setting using no routine post-dilatation protocol. Whether these findings have impact on scaffold mid-term results as well as on clinical outcome has to be investigated in larger, randomized trials.

A PDF file should load here. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a PDF plug-in installed and enabled in your browser.

Alternatively, you can download the file locally and open with any standalone PDF reader:

http://www.biomedcentral.com/content/pdf/s12872-016-0296-1.pdf

Mechanical properties of the everolimus-eluting bioresorbable vascular scaffold compared to the metallic everolimus-eluting stent

Dalos et al. BMC Cardiovascular Disorders Mechanical properties of the everolimus- eluting bioresorbable vascular scaffold compared to the metallic everolimus- eluting stent Daniel Dalos 0 Clemens Gangl 0 Christian Roth 0 Lisa Krenn 0 Sabine Scherzer 0 Markus Vertesich 0 Irene Lang 0 Gerald Maurer 0 Thomas Neunteufl 2 Rudolf Berger 1 Georg Delle-Karth 3 0 Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna , Waehringer Guertel 18-20, 1090 Vienna , Austria 1 Department of Internal Medicine, Division of Cardiology, Barmherzige Brüder Eisenstadt , Eisenstadt , Austria 2 Department of Internal Medicine, Division of Cardiology, University Hospital Krems , Krems , Austria 3 Department of Internal Medicine, Division of Cardiology, Krankenhaus Hietzing , Vienna , Austria Background: Everolimus-eluting bioresorbable vascular scaffolds (BVS) represent an innovative treatment option for coronary artery disease. Clinical and angiographic results seem promising, however, data on its immediate procedural performance are still scarce. The aim of our study was to assess the mechanical properties of BVS by Optical Coherence Tomography (OCT) in clinical routine. Methods: Post-implantation OCT images of 40 BVS were retrospectively compared to those of 40 metallic everolimus-eluting stents (EES). Post-procedural device related morphological features were assessed. This included incidences of gross underexpansion and the stent eccentricity index (SEI, minimum/maximum diameter) as a measure for focal radial strength. Results: Patients receiving BVS were younger than those with EES (54.0 ± 11.2 years versus 61.7 ± 11.4 years, p = 0.012), the remaining baseline, vessel and lesion characteristics were comparable between groups. Lesion pre-dilatation was more frequently performed and inflation time was longer in the BVS than in the EES group (n = 34 versus n = 23, p = 0. 006 and 44.2 ± 12.8 versus 25.6 ± 8.4 seconds, p < 0.001, respectively). There were no significant differences in maximal inflation pressures and post-dilatation frequencies with non-compliant balloons between groups. Whereas gross device underexpansion was not significantly different, SEI was significantly lower in the BVS group (n = 12 (30 %) versus n = 14 (35 %), p = 0.812 and 0.69 ± 0.08 versus 0.76 ± 0.09, p < 0.001, respectively). There was no difference in major adverse cardiac event-rate at six months. Conclusion: Our data show that focal radial expansion was significantly reduced in BVS compared to EES in a clinical routine setting using no routine post-dilatation protocol. Whether these findings have impact on scaffold mid-term results as well as on clinical outcome has to be investigated in larger, randomized trials. Bioresorbable Scaffold; Drug-Eluting Stent; Optical Coherence Tomography Background Drug eluting stents (DES) have shown to be highly effective in the treatment of patients with coronary artery disease [ 1–3 ] as neointimal hyperplasia after a vascular injury was reduced compared to when bare metal stents were used [ 2, 3 ]. Nevertheless, delayed or absent strut endothelialization, persistent or acquired malapposition and neoatherosclerosis of DES contribute to late stent failure rates which are in the range of 1-2 % a year within the first three years after implantation [ 4–6 ]. In addition stent fractures especially at hinge points of the coronary vessels and the lack of adaptive remodelling processes in the artery wall can contribute to late events. Bioresorbable vascular scaffolds (BVS) were developed in order to reduce those potential adverse events after a coronary intervention. After the bioresorption process is completed there will not be any potential triggers for late adverse events [ 7 ]. In contrast to vessels caged by metallic stents, vessels transiently scaffolded by bioresorbable materials are able to perform vasoconstriction and vasodilation and therefore could also contribute to better symptom control in patients with coronary artery disease [ 8–11 ]. It was also shown that BVS are characterized by a better conformability to the vessel compared to metallic stents [12]. On the other hand it is still unclear if the radial strength provided by BVS is sufficient throughout various clinical scenarios. It has been shown that metallic stents generate a larger acute lumen gain compared to BVS, but scaffold/stent type was not predictive for acute recoil [ 13 ]. Intravascular imaging data describing device strength and expansion are still scarce. The aim of the present study was to assess the mechanical properties of BVS by Optical Coherence Tomography (OCT) in clinical routine. Methods Patients Between March and June 2013, 26 consecutive patients underwent OCT immediately after implantation of 40 BVS (Absorb, Abbott Vascular, Santa Clara, CA, USA). Elective patients as well as patients presenting with acute coronary syndrome (ACS) were included. The OCT data of these patients (...truncated)


This is a preview of a remote PDF: http://www.biomedcentral.com/content/pdf/s12872-016-0296-1.pdf

Daniel Dalos, Clemens Gangl, Christian Roth, Lisa Krenn, Sabine Scherzer, Markus Vertesich, Irene Lang, Gerald Maurer, Thomas Neunteufl, Rudolf Berger, Georg Delle-Karth. Mechanical properties of the everolimus-eluting bioresorbable vascular scaffold compared to the metallic everolimus-eluting stent, BMC Cardiovascular Disorders, 2016, pp. 104, 16, DOI: 10.1186/s12872-016-0296-1